Cadillac Cadillac 1973 Install guide

1 973 CADILLAC
SHOP MANUAL
ALL
SERIES
IMPORTANT SAFETY NOTICE
Proper service and repair is important to the safe, reliable operation of all
motor vehicles. The service procedures recommended by Cadillac and
described inthis service manual are effective methods for performing service
operations. Some of these service operationsrequirethe use oftools specially
designed for the purpose. The special tools should be used when and as
recommended.
It is important to note that some warnings against the use of specific service
methods that can damage the vehicle or render
it unsafe are stated in this
service manual.
It is also important to understand these warnings are not
exhaustive. Cadillac could not possibly know, evaluate and advise theservice
trade of all conceivable ways inwhich service might bedoneor of the possible
hazardous consequences of each way. Consequently, Cadillac has not under-
taken any such broad evaluation. Accordingly, anyone who uses a service
procedure or tool which is not recommended by Cadillac must first satisfy
himself thoroughly that neither his safety nor vehicle safety will be
jeopardized
by theservice method heselects.

1 973
CADILLAC
SHOP
MANUAL
Service information pertaining to features exclusive to the
Eldorado is provided at the back of the individual sections in
this manual. All other service information for the Eldorado is
the same as that described in the forward portion of the
individual sections.
Ail information, illustrations, and specificationscontained in
this manual are based on the latest product information
available at the time of publication approval. The right is
reservedto make changes at any time without notice.
Service Department
CADILLAC MOTOR CAR DIVISION
General Motors Corporation
Detroit, Michigan 48232
Printed in U.S.A. 9-72
@ General Motors Corporation 1972
Part No. 109 9635
SECTION NO. P,
1
mi
Cruise Control
e
16
26
Twilight Sentinel 32
Rear Window De-Fogger 39
Lamp Monitor System 41
Low Washer Fluid System
I 44
45
ii

THE CADILLAC CERTIFIED CRAFTSMAN'S LEAGUE
CADILLAC CRAFTSMAN CODE
HEREBY pledge myself in all my work on
Cadillac cars, to be thorough and exact in diag-
nosing trouble; to recommend only that service
which is to the best interest ofthe owner;to perform
that work for which
I am responsible in accordance
with Cadillac standards to the best ofmy ability,and
in all my dealings with Cadillac owners, to be cour-
teous, honest, and ethical; and to do everything
within my power to further the owner's satisfaction
and promote his good will to Caaillac and to my
dealer.
The Cadillac Certified Craftsman's League is a program sponsored by Cadillac Motor Car Division
for the benefit of authorized dealer's service departments. Participation in the League is open to
Cadillac servicemen and partsmen, including department managers and apprentices. Enrollment
information is available from the Zone Service Representative.

GENERAL INFORMATION, MAINTENANCE AND LUBRICATION 0-1
GENERAL INFORMATION, MAINTENANCE AND LUBRICATION
Foreword
This Shop Manual has been prepared by the Service
Department of the Cadillac Motor Car Division toaid in
servicing 1973 model Cadillac automobiles. It is in-
tended primarily for servicemen who are familiar with
earlier model Cadillacs. It includes complete information
on service procedures and specifications pertaining to all
1973 Cadillac cars except body service information
which is covered in a separate manual. Refer to the body
service manual for servicing Cadillac body items.
Arrangement of the Manual
The title page contains a rapid reference section
index with headings corresponding to the page tabs at
the beginning of each section. A Table of Contents is
provided at the beginning of each section that contains
more than one major subject. A complete alphabetical
index is located at the back of the manual. The section
sequence used in this manual has been arranged to con-
form with the ShopManuals of other
GM car lines.
The individual sections include theory of operation
and diagnosis at the beginning of each section followed
by service adjustments and replacement procedures. An
illustrated list of special tools, a torque requirement
chart, and specifications are provided at the end of each
section.
Service information pertaining only to those features
that are exclusive to the Eldorado is provided at the
back of the individual sections in the manual. For
Eldorado service procedures and recommendations not
listed, refer to the forward part of the appropriate
section, as these service procedures are similar to those
on other 1973Cadillac cars.
GENERAL INFORMATION
Vehicle Identification Number
identification number is decoded as follows:
The last six digits of the number determine the se-
Each 1973 Cadillac automobile or Commercial quence in which the car was built. These numbers are
Chassis carries a 13-digit vehicle identification number utilized as follows:
used for license and insurance identification and in
general reference to the automobile. The number is 100001through 350000
- Detroit built "C" bodies
located on the forward lower edge of the windshield 350001 through 400000
- Linden built DeVille
trim molding at the driver's side of the car where it is series
visible through the windshield. The 1973Cadillac vehicle 400001 through 450000
- Detroit built "E" bodies
I -
Car Line Series
C
c4 R ] looGi
1 6 denotes Cadillac
Division
- -
Sequence in which car
was built.
Plant designation
Q - Detroit
E - Linden
Model Year (1973)
Engine Designation
R - 472 Cu. In.
S - 500Cu. In.

0-2 GENERAL INFORMATION. MAINTENANCE AND LUBRICATION
ENGINE UNlT NUMBER ON
BLOCK BEHIND LEFT CYLINDER
HEAD; V.I.N. DERIVATIVE ON
BLOCK BEHIND INTAKE MANIFOLD
TURBO HYDRAMATIC TRANSMISSION
UNlT NUMBER PLATE LOCATED
ON
RIGHT SIDE OF CASE (EXCEPT 6L)
GUIDE-MATIC PHOTOCELL AND AM-
PLIFIER SERIAL NUMBER LABEL LO-
CATED ON BACK OF UNlT
ViHlCLF 1l)l PNII CATION NUMBER
LOCATED ON PLATE RIVETED TO
COWL BAR IN THE LOWER LEFT
HAND CORNER OF THE WINDSHIELD.
VEHICLE IDtNTIfICATION NUMRtR
DERIVATIVE LOCATED ON LEFT
SlDE OF TRANSMISSION CASE
(EXCEPT 6L)
A C COMPRESSOR SERIAL NUMBER
LABEL LOCATED ON REAR PORTION
OF COMPRESSOR HOUSING.
TURBO HYDKA MATlC TRANSMIS-
SION UNlT NUMBER PLATE LOCAT-
ED
ON LEFT S DE OF COlvVERTER
hOUSlNG.VEH C.E IDElvTIFICATION
NUMBER DERIVATIVE LOCATED ON
VERTICAL SUPPORT PAD ON LEFT
OF TRANSMISSION (6L ONLY)
- -
-- -
TWLICIHT '>IPJIINI I AMPLFltR ',I i'AL
NUMBER LAREL LOCATED ON COVFR
OF UNlT
RADIO SERIAL NUMRER TAG LOCATED
ON RIGHT SlDE
OF TUNER
Fig. 0-1 Unit Number Location
-- -
- ~~ ~
.. -~

GENERAL INFORMATION, MAINTENANCE AND LUBRICATION 0-3
The series and model section (2nd, 3rd, and 4th
digits) of the vehicle identification number may be
further decoded using the above chart. These two body
style numbers are interchangeable when referring to the
automobile.
A nine-digit derivative of the vehicle identification
number is applied to the engine and transmission at the
locations shown in Fig. 0-1. This derivative is used for
in-plant control of these Assemblies and may be used by
law enforcement or other officials to identify proper
enginechassis combinations. This number should con-
tain the same numbers and letters as the vehicle identifi-
cation number but in the condensed form shown below.
6 3
Q 100001
Sequence in which car
was built
Plant
Q - Detroit
E - Linden
Model Year (1973)
6 denotes Cadillac Division
\
V.I. BODY STYLES
6C47
6C49
6D47
6D49
6B69
6F23
6F33
6L47
,$L67
6290
MODEL NAME
Calais Coupe
Calais Sedan
Coupe DeVille
Sedan DeVille
Fleetwood Sixty Special Brougham
Fleetwood Seventy-Five Sedan
Fleetwood Seventy-Five Limousine
Eldorado coupe
Eldorado Convertible
Commercial Chassis
I
Identification Numbers
PARTS AND FLAT RATE
MANUAL BODY STYLE
6CC47
6CC49
6CD47
6CD49
6CB69
6DF23
6DF33
6EL47
6EL67
62290
Locations of identification numbers on various units
are shown in Fig. 0-1. The identification number on the
unit should always appear on product report forms sent
to the Central Office such as PIR's, Claim Tags, Pre-
I Delivery Reports and, when required, on Warranty
I
Claims. The 13 digit Vehicle Identification Number is
necessary when reporting product information on any
vehicle.
t
Body Name Plate
A body name plate, Fig. 0-2, is attached to the top
surface of the shroud on the right side, under the hood,
near the cowl. The name plate carries the style number,
trim number, body number, and paint number in the
areas indicated by ST, TR, BODY, and PAINT.
The first two digits of the style number (ST) indicate
the model year while the remaining five digits indicate
the body style.
The numbers following
TR indicate the interior trim
color and seat type.
The body number consists of three letters indicating
the assembly plant and six digits indicating the sequence
in which the body was built.
The first two digits of the paint number indicate
color of thebody shell and chassis sheet metal; the letter
indicates color of convertible and vinyl tops.
The number-letter code at the left below trim indi-
catesdate of assembly (month-week).
/ BODY BY FISHER \
ST 73-6CD47 FWD 123456 BDY
TR 351 11-K PNT
oooO
GENERAL MOTORS CORPORATION
0
CERTIFIES TO THE DEALER THAT THIS
VEHICLE CONFORMS TO ALL U.S. FEDERAL
MOTOR VEHICLE SAFETY STANDARDS
APPLICABLE AT TIME OF MANUFACTURE
1
Fig. 0-2 Body Name Plate

0-4 GENERAL INFORMATION, MAINTENANCE AND LUBRICATION
GENERAL DESCRIPTION AND SPECIFICATIONS
Hoist Recommendations
(Except Eldorado)
CAUTION: Failrrrr to follow the recommenda-
tions orrtlined below ma)' reszrlt in unsatisfactory
vehicle performance, or a durability failure which
may result in loss of control of the vehicle.
Description
Fleetwood Sixty Special
Brougham
Calais Sedan
Calais Coupe
Sedan de Ville
Coupe de Ville
Eldorado Coupe
Eldorado Convertible
Fleetwood Seventy-Five
The preferred type of hoist for lifting 1973Cadillacs
is one that engages the front suspension and rear axle, or
all four wheels.
The front lower suspension arm is designed with a
flattened portion on the flange of the arm for use with
lifting equipment that engages the suspension system.
When using lifting equipment of this type, make certain
that the car is properly centered over the hoist and that
the hoist arms are positioned under the flattened portion
of the flange, Fig. 0.3, outboard of the safety locaters. If
the hoist arms are not properly positioned in relation to
the lower support arms, damage to the steering linkage
or brake lines could result, or the car may shift on the
hoist.
Overall
Length
(Inches)
231.5
228.5
228.5
228.5
228.5
222.0
222.0
250.0
250.0
253.9
CAUTION: The rear lower control arms should
never be used asa liftpoint.
Vehicle
Identifi-
cation
Number
6869
6C49
6C47
6D49
6D47
6L47
6L67
If a frameengaging hoist is used, certain precautions
must be observed. The shaded areas of the frame, Fig.
04,indicate the only acceptable positions for lift pads.
Pads must be used in these areas with maximum surface
contact and must contact only those parts of the frame
indicated.
Overall
Height
(Inches)
55.5
54.6
54.1
54.6
54.1
53.9
54.3
57.8
57.7
-
Sedan
Fleetwood Seventy-Five
Limousine
Commercial Chassis 6290
(NOTE: Certain cars are equipped at these loca-
tions with special brackets used for rail shipment. If such
a situation is encountered, be sure to engage bracket
fully rather than at the edges.)
151.5
151.5
157.5
WEIGHT
4999
4850
4797
4882
4822
4777
4863
Do not use a frame-engaging hoist to raise the Fleet-
wood Seventy-Five Sedan and Limousine or the Com-
mercial Chassis.
Maxi-
mum
Width
(Inches)
79.8
79.8
79.8
79.8
79.8
79.8
79.8
79.8
79.8
-
Wheel-
base
(Inches)
133.0
130.0
130.0
130.0
130.0
126.3
126.3
CAUTION: The shock absorbers act as rebound
stops for the rear suspension Under no circum-
stances should the rear end ofcar be raised so that
rrar suspension is in rebound position while dis.
connecting shock absorbers.
Hoist Recommendations
(Eldorado Only)
Tread
Width
CAUTION: Failure to follow the recommenda-
Front
63.3
63.3
63.3
63.3
63.3
63.66
63.66
63.3
63.3
63.3
tions outlined below mav result in unsatisfactory
vehicle performance, or a durability failure which
may result in loss of control of the vehicle.
Rear
63.3
63.3
63.3
63.3
63.3
63.59
63.59
63.3
63.3
65.0
The preferred type of hoist for lifting the 1973
Eldorado is one that engages the front suspension and
rear axle or all fourwheels.
Use of a suspension-engaging hoist requires that
certain procedures bc observed.
Be sure front hoist saddle adapters engage lower
suspension arm just inboard of stabilizer linkage (both
sides), Fig. 0-5, to prevent damage to steering linkage. At
the rear, Fig. 0-6, place "saddles" of hoist in maximum
"in" ~ositionto prevent dama~eto Automatic Level
contrb~overtravei lever bracket, fuel lines, and brake
Fig.
0-3 Front Hoist Saddle Position-Except Eldorado lines.
-~ ~~ ~
~ -~~~
. -
- --

GENERAL INFORMATION, MAINTENANCE AND LUBRICATION 0-5
5 FRONT WHEELS
FRONT BOTTOM
CORNER OF DOOR
ON
CLEARANCE
7.90
Fig. 0-4 Lifting Locations-Except Eldorado and Commercial Chassis
Fig.
0-5 Front Hoist Saddle Position-Eldorado Fig.
0-6 Rear Hoist Saddle Position-Eldorado
W' - ~ ~

0-6 GENERAL INFORMATION, MAINTENANCE AND LUBRICATION
1
Fig. 0-7 Lifting Locations-Eldorado
CAUTION: The rear lower control arm should
a situation is encountered, be sure to engage bracket
never be used as a lift point.
fully rather than at the edges.)
If a frame engaging hoist is used, certain precautions An additional precaution of using two floor stands
must also be observed. under the front frame cross member of the Eldorado is
Make sure that hoist adapters and "tabs" are in recommended when heavy mechanical operations are to
lowered position before driving on or off the lift. be performed. Be sure to remove these stands before
attemptingto lower the vehicle.
Position hoist adapter "tabs" in raised position to If a drive-on hoist is used, be sure the center line
obtain maximum possible height between frame and
relationship as stated above is also applied,Fig. 0-7.
hoist. When supporting the Eldorado with a floor jack or
Be sure to position tabs in exact locations jack stands, the supports should be placed at the sus.
shown in the shaded areas of Fig. 0-7 and make
the
pendon lift points or the frame contact lift points. The
centerline of the door is behind the centerline of the lift ~ld~~~d~should
never be Npported at the extreme ends
post for proper weight distribution. of the frame or at the center of the frame side rail or
(NOTE: Certain cars are equipped at these loca- lifted at the front or rear bumper with anything other
tionswith specialbrackets used for rail shipment. If such than the bumper jack provided with the car.

GENERAL INFORMATION, MAINTENANCE AND LUBRICATION
0-7
SERVICE INFORMATION
Complete instructionsfor lubrication of the various
points of the 1973Cadillacsaredescribed in this section.
An Engine Oil Change Interval and Viscosity Chart, and
a Fluid Capacity Chart appear at the end of this section,
on Page 0-21. The Maintenance Schedule, Pages 0-18
through 0-20, is based upon service at time of engine oil
change, unless otherwise specified.
The recommended engine oil change interval, regard-
less of season, is every 4 months, never to exceed 6,000
miles. More frequent changes are required with stopand
go operation, prolonged idling periods, trailer towing,
dusty road travel, or during extended cold or wet cli-
matic conditions. In such cases, an oil change is recom-
mended after 2,000or even 1,000miles of driving.
The various points on the chassis that require a lubri-
cant are listed in the Maintenance Schedulc, Pages 0-18
through 0-20. Maintenance should be performed accord-
ing to the intervals specified on the Schedule. Use fac-
tory recommended fluids in the quantities specified.
1. Front Suspension
Spherical joints are used on the front suspension
system at the outer ends of the upper and lower control
arms, and at the inner and outer steering linkage tie rod
pivots.
These joints should not need repacking throughout
their entire service life under normal driving conditions.
At the time of an engine oil change, visually inspect all
joint seals for any indication of damage, such as cuts,
tears, ruptures, worn spots, etc. If a damaged seal is
evident, the seal must be replaced and the joint
repacked. Special front suspension lubricant is recom-
mended for the repacking operation.
The procedure for replacing and repacking the upper
and lower suspension arm spherical joint seals is de-
scribed in Section 3, Notes 25 and 28 for Eldorados and
Notes 8,9and 10for all other cars.
Extended life spherical joints are used at both inner
and outer tie rod pivots. The only maintenance normally
required is to inspect the seals for physical damage each
time the engine oil is changed. If periodic inspection
reveals a damaged seal, the seal may be replaced and the
joint repacked as described in Section
9, Note 22. If a
loose joint is found, replace the joint as described in
Section 9, Notes
17 and 34.
2. Engine
a. EngineOil Recommendations
The original factory fill oil will perform satisfactorily
during the normal change interval specified on the
Engine Oil Change Interval and Viscosity Chart, Page
0.21, because this oil meets the specifications for service
"SE". The same chart should also be consulted for
factory recommendations if additional oil should be
necessary prior to the normal change interval.
The use of proper engine oil is the best assurance of
continued reliability and performance from a Cadillac
engine. Cadillac does not recommend oils by brand
name, as assurance of oil quality is the responsibility of
the refiner. Instead, the factory recommends oils that,
Fig.
0-8 Adding Engine Oil
according to their labels, are intended for service "SE".
Cadillac Servicemen should assist owners in the selection
of the proper oil that meets the above requirements, as
well as the proper viscosity numher for a particular area
and season.
In areas where the temperature seldom drops below
zero, most 10W or 10W-40oils are satisfactory for easy
starting of the engine. When the temperature is fre-
quently near or below zero, a SW-20 or 5W-30 oil is
recommended.
(NOTE: W-20 oils are not recommended for sus-
tained high speed driving. Non detergent and low quality
oils are specifically not recommended for any type of
service.)
b. Adding EngineOil (Fig. 08)
Always maintain the correct oil level. Oil should be
added only when the level reaches the "Add One Quart"
mark on the dipstick. Do
NOT add oil if oil level is
above the "Add
I Qt" line, or foaming may result. For
an accurate check of oil level wait 10to 15minutesafter
shutting off engine to allow time for oil to drain back
into pan. Always check engine oil level when engine is
hot.
Engine oil is added by removing the oil filler cap on
the right rocker arm cover, Fig.
0-8.
c. Changing Engine Oil
The engine should be drained of oil only after it has
been warmed to normal operating temperature. The
benefits of draining are minimized if the crankcase is
drained when the engine is cold, as some suspended
foreign matter will cling to the internal engine parts and
will not drain with the slower moving colder oil.
The Engine Oil Change Interval and Viscosity Chart,
Page 0-21, will serve as a guide for the proper oil change
interval and oil viscosity to be used at the prevailing
temperature. It is unnecessary to change the oil for the
occasional unseasonably cold or warm day encountered
during the fall or spring season.

08 GENERP RMATION, MAINTENANCE AND LUBRICATION
Fig. 09 Dipstick 1.ocations-Eldorado
The capacity is 4 quarts (5 quarts on Eldorado). Do
not add more than 4 auarts exceot when chaneine oil
" -
fijter in which case 5 quarts should be used (6 quartson
Eldorado). Fig. 0-1 1 Engine Oil Filter
The dipstick locationsfor the Eldorado are shown
in
Fig. 0-9. , . b. Carburetor Air Cleaner
(NOTE: The Eldorado engine has two oil pan drain The carburetor air cleaner, Fig. 0-10, incorporates a
plugs which must he opened when changing oil.) replaceable paper element.
A new air cleaner element
should be installed every 24,000 miles. More frequent
3. Engine Accessories
a. Distributor
The Cadillac distributor is permanently lubricated
and requires no periodic oiling. However, in the event
the distributor is disassembled and the shaft or breaker
plate is removed, the wick in the oil reservoir should be
moistened with light weight engine oil.
When the contact point set is changed, the distri-
butor cam lubricator should he rotated
112 turn. At the
second engine tune up, 24,000 miles, the lubricator
should be replaced. Rotate or replace lubricator with
each engine tune-up.
Fig.
010 Thermac Air Cleaner Assembly
replacement of the element may be necessary
if the car
is constantlv driven in dustv areas.
A visual ins~ectionof
.
the element is recommended periodically to make cer-
tain that it is properly seated and that there is no indica-
tion of dust leakage. If dirt or damage is indicated at
time of visual inspection, the element should be
changed. To replace element, proceed as follows:
I. Remove cover from carburetor air cleaner.
2. Remove element and discard.
3. Wipe all dirt from inside air cleaner cover.
4. Install a new element onair cleaner base, making
certain that it is properly seated and replace air cleaner
cover.
c. EngineOil Filter (Fig. 0-11)
The engine oil filter is of the spin-on,fi~ll-flowtype.
It is recommended that the filter be replaced at time of
first engine oil change and every second oil change there-
after.
The full-flow type oil filter filters 10(Ma of the oil
delivered by the oil pump. For this reason, it is very
important that the recommended oil filter change inter-
vals be followed.
The oil filter is mounted on the front right side of
the engine, Fig. 0-1I. Access to the filter isgained from
under the car. Replacement procedure is as follows:
1. Position car on hoist.
2. Unscrew filter from base and discard.
3. Wipe gasket area ofbase clean.
4. Place a light film of silicone on top of gasket and
screw filter on stud of filter base by hand until gasket
tooclics filter base. Then tighten element an additional
213 of 3 turn.

GENERAL INFORMATION, MAINTENANCE AND LUBRICATION 0-9 \
5. Add 1quart of oil to engine crankcase.
(NOTE: If engine oil is changed in conjunction
with oil filter replacement, add a total of
5 quarts of oil
to engine crankcase (6 on Eldorado).)
6. Operate engineat fast idle and check for oil leaks
at filter base.
7. After engine has run for 3 to 4 minutes, stop
engine and check oil level.
4. Battery
The battery electrolyte level should be checked at
every engine oil change. In warm weather, a check
should be made at two-week intervals. An electrolyte
level indicator vent cap is located in the second cell cap
from the positivebattery terminal.
The indicator cap makes it unnecessary to remove
cell vent caps when checking fluid level. A dark (black)
spot in the center of this vent cap is visible when elec-
trolyte is at the normal level.
If 0t any time the electrolyte level drops below
normal, the spot changes from black to an off-white
color. When an off-white condition is encountered, all
cell fluids must be adjusted to their correct level. This is
accomplished by adding colorless, odorless drinking
water to raise the fluid level to the bottom of the slot in
each vent-well.
CAUTION: Do not overfll battery or add any
substance to fluid except colorless, odorless
drinking water.
When replacing battery cables retorque screws to 70
inch-pounds.
CAUTION: Over torquing terminal screws may
strip threads in terminal or short out battery. Use
only proper size
(318 x 16 coarse).
Keep battery, cable clamps, and hold-down bracket
-. -.
clean. If necessary, clean with a solution of ammonia
and water, or baking soda and water. Flush off with
water and apply petroleum jelly to cable clamps and
terminals to retard corrosion.
5. Emission Control Systems
The Federal Clean Air Act stipulates that it is unlaw-
ful "for any person to remove or render inoperative any
device or element of design on a motor vehicle in com-
pliance with regulations." A further provision stipulates
that "the manufacturer shall furnish with each new
Motor vehicle"
. . . "written instructions for the main-
tenance and use of the vehicle or engine by the ultimate
purchaser as may be reasonable and necessary to assure
the proper functioning of emission control devices and
systems."
a. ThermacAir Cleaner
The thermac air cleaner should be inspected to make
certain that all hoses and ducts are intact and correctly
installed. Operational function should be checked as
described in Section 6,Note
79.
b. Choke
Choke mechanism should be checked for free opera-
tion after four months or 6,000 miles (whichever comes
first) and at 12 month/12,000 mile intervals thereafter.
A binding condition may have developed from gum for-
mation on the choke shaft or from damage. Choke shafts
can usually be cleaned without disassembly by using
X-66 Carburetor Conditioner or equivalent.
c. Carburetor to Manifold Screws
Carburetor attaching screws should be carefully
adjusted to correct torque to compensate for com-
pression of gasket at first 4 months or 6,000 miles of
vehicle operation only. Correct torque on front screws is
10 foot-pounds. Tighten rear screws to 14 foot-pounds.
d. Fuel Filter
A clogged fuel pump filter may restrict fuel flow.
Replace filter each 12months or 12,000miles whichever
occurs first.
e. Spark Plugs
Spark plugs must be replaced at 6,000 miles when
operating with leaded fuels or at 12,000 miles when
using unleaded fuels.
Use of leaded fuels results in lead deposits on spark
plugs and can cause misfiring. Where misfiring occurs
prior to 6,000 miles, spark plugs in good condition can
often be cleaned, tested, and reinstalled in an engine
with acceptable results.
f. EngineCompression
Minimum compression recorded in any one cylinder
should not be lessthan 70% of highest cylinder.
This test should be performed to provide reasonable
assurance that engine condition is sufficiently efficient
to prevent leakage of unburned gases. Check compres-
sion every 24 months or 24,000 miles.
g. Distributor Points,Cam Lubricator
Distributor points should be inspected prior to per-
formance of tune-up adjustments. Burned or pitted
points must be replaced. Points in good condition may
be reused after readjustment and the rotation or installa-
tion of the cam lubricator. Points should be replaced
every 12 months or 12,000 miles. New cam lubricator
should be installed at least every 24,000 miles.
h. DistributorCap
The interior and exterior of the distributor cap
should be carefully inspected and cleaned to prevent
misfiring and deterioration every 24 months or 24,000
miles.
i. Spark PlugWires
Inspect spark plug wires for evidence of checking or
cracking of exterior insulation and a tight fit in the dis-
tributor cap and spark plugs. Exterior of wires should be
cleaned, any evidence of corrosion on ends removed and
wire replaced if deteriorated. Check should be made
after first 24 months or 24,000 miles and at every 12
month/12,000 miles thereafter.

0-1 0 GENERAL INFORMATION, MAINTENANCE AND LUBRICATION
j. Timing, Dwell, ldleSpeed
These adjustments must be performed accurately,
following the specifications and procedures described in
Section 6, Notes 36, 37, and 62b. Adjustments must be
made with test equipment known to be accurate.
Proper functioning of the carburetor is particularly
essential to control of emissions. Correct mixtures for
emission compliance and idle quality have been preset
by Cadillac. Plastic idle mixture limiters are installed on
the idle mixture screws to prevent unauthorized adjust-
ment.
These idle limiters are
go-t to be removed unless
made necessary by some major carburetor repair or
replacement &ch affects the idle screw adjustment.
Thereafter, the idle mixture must be readjusted as de-
scribed in Section 6, Note 62a, and a new - red plastic
limiter installed.
k. Thermal Vacuum Switch & Hoses
The thermal vacuum switch should be tested every
12 months or 12,000 miles as described in Section 6,
Note 28b. Vacuum control hoses must be in good condi-
tion, correctly installed and fit tightly.
I. Exhaust Gas Recirculation System
This system should be tested as described in Section
6, Note 80 at 12 month/12,000 mile intervals when us-
ing leaded fuels or at 24 month/24,000 mile periods if
using unleaded fuels.
m. EvaporationControl System Fuel
& Vapor Lines
All fuel and vapor lines and hoses must be in good
condition with no signs of leakage. Any damaged or
deteriorated lines or hoses must be replaced. All lines
should be inspected for proper connections and correct
routing.
n. EvaporationControl System Canister
Check canister for cracks or damage when replacing
the canister filter. Replace filter every 24 months or
24,000 miles.
o. EvaporationCanister Filter
Remove canister and replace filter in lower section
of canister.
p. Positive Crankcase Ventilation System
The PCV system should be checked for satisfactory
operation at 12-month or 12,000-mile intervals using a
tester such as CT-3.
Replace the PCV glveat 24 months or 24,000 mile
intervals (whichever occurs first). PCV valve hose, when
removed for valve replacement, should be blown out
with an air hose to make certain that it
is clean. The
PCV valve should be replaced at 12 months or 12,000
miles (whichever occurs first) when the vehicle is used
under the following conditions:
Driving in dusty conditions
Extensive idling
Trailer towing
Short trip operation at freezing temperatures
(engine not thoroughly warmed-up)
Cleaning of the crankcase ventilating breather is
important in order to provide proper crankcase
breathing. The breather is located on the left rocker arm
cover. The filtering material in the unit must be cleaned
with solvent at every oil filter change. Do oil the
filtering element.
q. ldleStop Solenoid
Check for proper operation every 12 months or
12,000miles. Replace solenoid if inoperative.
r. Air Injection Reactor Pump &
Engine Drive Belts
Engine belts must be properly adjusted. A slipping
belt will not operate the AIR pump satisfactorily.
Deteriorated belts should be replaced.
s. Air Injection Reactor System
Hoses
& Connections
Check AIR system hoses and fittings for loose
connections and deterioration. Test diverter valve by
quickly depressing and releasing throttle and holding
hand under diverter valve exhaust. If exhausted air can
be felt during engine deceleration, valve is operating
properly. Inoperative diverter valves should be replaced.
t. Test Coolant Level
Engine coolant should be checked for proper level
and for corrosion protection to at least -40°F and for
freeze protection to the lowest temperature expected
during the period of vehicle operation. Each two years
or 24,000 miles, whichever first occurs, cooling system
must be drained, flushed and refilled with a new coolant
solution. See Section 6,Note 4, for additional details on
cooling system care.
u. Radiator Core Exterior
For proper cooling efficiency, the exterior of the
radiator core and A/C condenser, if so equipped, must
be kept clean. Light brushing and reverse air flow is
usually a satisfactory cleaning method. Insects can
usually be removed with a garden hose using light water
pressure.
v. FuelCap, Fuel Lines, and
Fuel Tank
The fuel tank, cap, and lines should be inspected for
road damage that could cause leakage. Inspect fuel cap
for correct sealing ability and indications of physical
damage. Replace any damaged or malfunctioning parts.
w. Automatic Transmission Fluid
Oil level in the automatic transmission must be
checked at each engine oil change. Under normal driving
conditions the transmission fluid should be changed
every 100,000 miles. Under unusual conditions such as
constant driving in heavy city traffic during hot weather,
trailer towing, etc. fluid should be changed at
50,000-mile intervals. It is important that transmission
fluid level be maintained at the full mark and not over

GENERAL INFORMATION, MAINTENANCE AND LUBRICATION 0-11
Fig. 0-12 Power Steering Pump Reservoir
filled. See Section 7, Note 6, for additional details on
transmission care.
6. Power Steering
The steering gear is lubricated by the power steering
fluid and requires no other lubricant. The fluid level in
the pump reservoir, Fig.
0.12, should be checked every
spring and fall after the engine is warm, and the reservoir
kept filled with special power steering fluid, Part
Number 1050017, or its equivalent. If the dipstick
indicates that the fluid level is extremely low, the unit
should be inspected for leaks and corrected immediately.
When making a complete fluid change, always use special
power steering fluid available from servicing parts ware-
houses. When topping off the fluid, if the special fluid is
not avsilable, Dexron Automatic Transmission Fluid or
equivalent may be used. Refer to Section 9, Note
1, for
checkingfluid level.
7. Power Brakes
The brake fluid level of both sections of the master
cylinder, Fig. 0-13, should be checked at every engine oil
change and every time the brakes are serviced. The
reservoir cover incorporates a diaphragm that provides a
seal between the reservoir fluid and the atmosphere to
prevent moisture absorption or dust contamination.
If either the front or rear brake reservoir is found to
be low, the related hydraulic system should be checked
for leaks. Then fill the reservoir with Super Heavy Duty
Brake Fluid, Part Number 5464831, or equivalent fluids
conforming to SAE 5-1703 specifications, to within 118
inch to 318 inch of the reservoir sealing surface.
Check travel of service brake pedal and the parking
brake pedal every 4 months never toexceed 6,000 miles.
Excessive brake pedal travel is an indication of the air in
the fluid or some other brake system malfunction.
Service brake pedal travel should not exceed 1.314
inch during normal brake pedal application of approxi-
mately 30 pounds force (2" on Eldorado). The parking
brake pedal should travel 1.314 inch to 2.314 inch with
moderate application (50 pounds force).
Refer to Section
5 for adjustment procedures should
either pedal travel be found incorrect.
8. Air Conditioner Compressor
The 6 cylinder compressor uses 525 viscosity oil. It
is important that only the type of oil recommended by
the compressor manufacturer be used. Refer to Section
1,Note 44f for lubricating recommendations.
9. Transmission
a. Fluid Recommendations
Dexron Type Automatic Transmission Fluid or fluid
of equivalent quality is recommended exclusively for use
in Cadillac automatic transmissions. It should be used
both for adding and refilling. Dexron fluid or its equiva-
lent incorporates additives not used in regular fluid-
additives that are essential for satisfactory transmission
performance. Fluid of this quality is distributed by
General Motors and by other oil marketers.
b. Checking Fluid Level
The transmission dipstick and filler tube is located
on the right side of the engine (left side on the Eldorado,
Fig. 0.9).
Fluid level should be checked at every engine oil
change. Add fluid, if necessary, until proper level is
indicated on dipstick. Proper fluid level is based on
operating temperature. See Figs. 0-14 and 0.15. At
normal operating temperature, 1 pint of fluid will
change the level from the low mark to the full mark on
the dipstick.
Fig.
0-13 Power Brake Reservoit

0-1 2 GENERAL INFORMATION, MAINTENANCE AND LUBRICATION
I
TRANSMISSION TEMPERATURE OF.
I
Fig. 0-14 Transmission Oil Level-Except Eldorado
When checking fluid level, first run engine at 800
rpm with shift lever in Park "P position for 1-112
,
minutes to make certain converter is full. Reduce engine
speed toslow idle, remove and wipe dipstick, then check
fluid level. With the engine still running, add fluid
through dipstick tube to bring fluid to proper level.
CAUTION: Do not overfill, as foaming may
occur when fluid heats up. If fluid level is too low,
especially when cold, complete loss of drive may
result after quick stops. Extremely lowfluid levels
will result indamage to the transmission.
level. Add fluid, if necessary, to bring to proper level,
Figs. 0-14and 0-1
5.
d. Oil Filter
The oil intake system incorporates an oil filter in the
transmission oil sump. The filter must be replaced after
the first 100,000 miles only, or after a major trans-
mission failure. The procedure for removing and
installingthe filter is described in Section 7, Note 6c.
e. Transmission Linkage
Lubricate all transmission linkage friction points
each spring and fall with a grade 3-zinc oxide grease
c. Transmission Fluid Change (except Eldorado). Lubricate Eldorado linkage with a
The transmission bottom pan should be drained gade lithium
soap grease.
every 100,000miles and fresh fluid added to obtain the
proper level on the dipstick. For cars subjected to heavy
city driving, or in commercial use where the engine is
regularly idled for prolonged periods, or for trailer
towing, the bottom pan should be drained every 50,000
miles.
1. Remove dipstick from filler tube and insert a
length of hose secured to a suction gun down the filler
tube. Remove enough transmission fluid so that bottom
pan will not overflow when removed.
2. Raise car and remove bottom pan. Empty pan
and cleanwith solvent.
3. Install bottom pan using a new gasket.
4. Lower car and add 2 quarts of transmission fluid
through filler tube.
5. Operate engine at 800 rpm for approximately
1-112 minutes with selector lever in park "P" position.
6. Reduce engine speed to slow idle and check fluid
10. Front Wheel Bearings (Except
Eldorado) Rear Wheel Bearings
(Eldorado Only)
These wheel bearings require repacking and adjusting
when the brake linings or pads are replaced. When
repacking these bearings, use a
#2 grade lithium hlgh
melting point wheel bearing grease free from any fillers
or abrasives. Refer to Section 3, Note 17 for repacking
procedure.
11. Differential (Except Eldorado)
Check the lubricant level in the differential only on
the first inspection and Add lubricant if necessary. The
differential lubricant level should be within 112 inch of
the lower edge of the filler hole. Each spring and fall,

GENERAL INFORMATION, MAINTENANCE AND LUBRICATION 0-1 3
\,
I I
I
TOO LOW,--
2.0 1 I 1 I 1 I
I I I I I 1 I I I I I I
--
50 60 70 80 90 100 110 120 130 140 150 160 170 180 190 200 210 220 230 240 250 260
TRANSMISSION TEMPERATURE OF.
Fig. 0-15 Transmission Oil Level-Eldorado
inspect differential assembly for external signs of leakage
and check lubricant level only if leakage is evident.
Either SAE
80 or SAE 90 GL-5 multi-purpose type
gear lubricant conforming to
MIL-L-2105-B specifica-
tions or the controlled differential lubricant can be used
for cars equipped with the standard differential. Cars
equipped with the Controlled Differential should use
only the special lubricant, Part Number
1050189, or its
equivalent, to assure the satisfactory operation of this
unit.
For vehicles normally operated in Canada, SAE
80
GL-5
gear lubricant is recommended.
When removing the filler plug, take extreme care not
to allow any dirt toenter the filler hole.
Draining and refilling of the differential is necessary
only when performing service operations inside the
differential.
12. Final Drive (Eldorado Only)
Check the lubricant level in the final drive only at
the first inspection and add lubricant if necessary. The
final drive lubricant level should be within
1/2 inch of
the lower edge of the filler hole. Each spring and fall,
inspect the final drive assembly for signs of external
leakage at the output shaft seals and at the pan gasket,
and check lubricant level only
if leakage is evident.
The factory recommended fluid for the final drive
assembly is either SAE 80 or SAE 90 GL5 multi-
purpose type gear lubricant conforming to
MIL-L-2105 -B specifications.
For vehicles normally operated
in Canada, SAE 80
GL-5
gear lubricant is recommended.
When removing the filler plug, take extreme care not
to allow any dirt to enter the filler hole.
Draining and refilling of the final drive is necessary
only at time of replacement.
13. Propeller Shaft
The propeller shaft does not require maintenance on
a regularly scheduled basis. Whenever the shaft is dis-
connected at the transmission, lubricate the outside
diameter of the front propeller shaft yoke with Auto-
matic Transmission Fluid, and the inside diameter with
propeller shaft slip yoke lubricant, or an equivalent
lubricant.
14. Additional Lubrication Points
The moveable mechanical parts of the body are
lubricated during production to insure proper and quiet
operation. If additional lubrication is required, lubri-
cants should be used according to the directions in
Section
2 of the body service manual.
In addition the following points should be lubricated
as indicated.
a. Hood Latch Mechanisms
Every 4 months or 6,000 miles, whichever occurs
first, lubricate hood latch assembly and hood hinges as
follows:
Wipe off any accumulation of dirt or contamination
on latch parts and apply lubricant to latch striker and
latch locking plate. Apply light engine oil to pivot points
in release mechanism, as well as primary and secondary
latch mechanism.
I

0-14 GENERAL INFORMATION, MAINTENANCE AND LUBRICATION
b. Hood Hinges
Lubricate hood hinges. Make hood hinge and latch
mechanism functional check to assure the assembly is
working correctly.
c. Fuel Filler Door Hinges
Apply a light coat of zinc oxide grease to all moving
joints of the fuel filler door hinges each spring and fall.
15. Points Requiring No Lubrication
No lubrication is required at the generator; water
pump; propeller shaft bearings; driven wheel bearings;
upper and lower rear control arms;rear springs; shackles,
or spring liners on Seventy-Five and Commercial Chassis;
starter motor; speedometer cable; Automatic Level Con-
trol Compressor; or front bumper Energy Absorbing
Devices, as all of these are packed with sufficient lubri-
cant at time of assembly.
Although periodic lubrication is not required,
replace damaged seals and add special lubricant, if re-
quired at the following locations:
a. Front upper and lower suspension arm pivot
points.
b. Pitman arm or idler arm pivots.
c. Tie rod linkage.
16. Vibration Complaints and
Correction
There are several excitation sources and many
responding systems which may cause an annoying vibra-
tion. The first step is to identify individual vibration
complaints by systematically classifying them, during a
road test, into one or more of the following categories:
(1) car speed sensitive, (2) engine speed sensitive, (3)
torque (throttle) sensitive, or (4) jounce sensitive.Since
each of these categories has specific vibrations associated
with it, this classification will give direction to the
proper area for analysis of the problem. This will
eliminate many components that cannot be the cause,
and will focus attention on only those items that can
contribute to the specific condition encountered.
1. Road Test
Prior to the initial road test, check and adjust the
tire pressures and install an engine tachometer. Next,
ride the car with the owner driving and have
him point
out the disturbance with which he is concerned.
(NOTE: The importance of riding the car with the
owner cannot be over-emphasized.)
If the condition is normal, and no corrective work is
needed, the owner should be told immediately. This
normalcy can be demonstrated with other vehicles,
pointing out that similar vehicles have the same
condition.
2. SensitivityClassification
Having verified that a vibration problem does exist,
the first step in correcting the problem is to classify it in
terms of one or more of the following sensitivity cate-
gories.
a. Car Speed Sensitive
Most vibration complaints will be found to be car
speed sensitive, i.e., the frequency of the excitation
depends only on the speed of the vehicle. To determine
if a given problem is car speed sensitive:
(1) Drive the car in "Drive Left" and record the car
speed and the engine RPM at which the problem occurs.
(2) Shift the car into "Drive Right" and again record
the car speed and the engine RPM at which the problem
occurs.
(3) If the problem occurs at the same car speed as
when the car was in "Drive Left", the vibration is car
speed sensitive.
(NOTE: It is possible thai two problems could
occur at the same car speed. Decelerate the engine to the
RPM obtained in Step 1 and check to see that problem
has disappeared. If it has not, there are two problems:
one of which occurs at the car speed determined in Step
1, while the second occurs at the engine speed deter-
mined in Step 1
.)
b. EngineSpeed Sensitive
Another group of vibration complaints will be found
to be engine speed sensitive, i.e., the frequency of the
excitation depends only on the speed of the engine,
independent of the speed of thevehcle. Hence, to deter-
mine if a given problem is engine speed sensitive:
(1) Drive the car in "Drive Left" and locate the
vibration problem. Record the car speed and the engine
RPM at which the problem occurs.
-
-
(2) Shift the car into "Drive Right" and again locate
the vibration problem. Record the car speed and the
engine RPM at which the problem occurs.
(3) If the problem occurs at the same engine speed
as, when the car was in "Drive Left", the vibration is
engine speed sensitive.
c. Torque Sensitive
A torque sensitive problem is one which increases in
intensity as the torque (power) output of the engine
increases, i.e., the intensity of the vibration increases as
the throttle opening is increased. To determine if a given
problem is torque sensitive:
(1) Drive the car in "Drive Left" and record the car
speed and engine RPM at which the problem occurs.
(2) Observe the condition while varying the throttle
position. Drive the car with steady throttle, slowly
increasing to heavy throttle by going up hill or applying
the brakes while increasing the throttle opening, and
slowly decreasing to minimum throttle by coasting
through thevibration speed.
(3) If the condition becomes more severe as the
throttle opening is increased, the vibration is torque
sensitive.
d. Jounce (or Load) Sensitive
A jounce (or load) sensitive problem is one which
varies in intensity as the height of the car changes with
respect to the surface of the road, i.e., the intensity
varies as therear springsare extended or compressed. To
determine if a given problem is jounce (or load)
sensitive:

GENERAL INFORMATION, MAINTENANCE AND LUBRICATION 0-1 5
(1) Drive the car and observe the condition with
varying passenger load.
(2) Alternatively, drive the car over a road that dips
in such a way that it causes the rear of the car tomove
up and downrelative tothe surface of the road. Keeping
a constant throttle, observe the condition.
(3) If the condition varies depending on the
passenger load (or varies as the rear of the car moves up
and down), the problem isjounce (or load) sensitive.
e. MultipleClassification
In the process of classifying vibration problems in
terms of these four sensitivity categories, you will find
that many problems fit more than one of the categories.
Combining these categories into their possible com-
binations, the majority of all vibration problems will fall
into one of thefollowing "classes" of categories:
(1) Engine speed sensitive only
(2) Car speed sensitive only
(3) Torque sensitive and car speed sensitive
(4) Torque sensitive and engine speed sensitive
3. EngineSpeed SensitiveOnly
Problems in this class may be duplicated with the car
stopped and the transmission in neutral by running the
engine at the RPM at which the disturbance was felt
during the road test. All additionalappra~salscan thus be
made under this "free engine" condition.
"Free engine" problems can be due to belts or
engine driven accessories (power steering pump,
generator, air conditioning compressor, fan, etc.). To
isolate the offending component, first check the torque
on all accessory mounting bracket bolts. Also, check the
condition and tension of all accessory drive belts. If any
abnormal conditions are found, correct and retest for
thevibration problem.
Air conditioning compressor problems can be diag-
nosed by turning compressor off and on while thevibra-
tion problem is being experienced.
If tightening the accessory mounting bolts and
adjusting the drive belt tensions fails to correct the dis-
turbance, remove accessory drive belts, one at a time,
tighten the accessory mounting bolts, and retest for the
problem. Continue to remove the belts one at a time
until the offending component is located.
CAUTION: With the water pump drive belt
removed, the engine will overheat rapidly; hence,
thisappraisal must be made very quickly.
4. Car Speed Sensitive Only
All tire problems are sensitive to car speed only.
Driveline unbalance or runout is sensitive to car speed at
the rate of one vibration per revolution (First Order).
Driveline vibrations at the rate of two or more vibrations
per revolution, oneither "C" cars or Eldorado, are sensi-
tive to both car speed and torque, and should not be
considered as "car speed sensitive only"
(NOTE: Vibration appraisal on the hoist should be
performed on car speed sensitive problems only.
Analysis of torque sensitive problems on stands will very
often lead to erroneous conclusions, due to the fact that
no appreciable torque is transmitted when the vehicle's
tires are not touching the pavement.)
CAUTION: This procedure should never be
attempted on the drive (front) wheels of an
Eldomdo. On these vehicles, evaluation must be
doneon theroad.
a. Suspension Hop and Tramp (Tire Balance)
In order toverify suspension hop & tramp as excited
by tire balance and/or runout, proceed asfollows:
(1) Install a complete set of known good wheel, tire,
and brake drum assemblies on the car and retest on the
road.
(NOTE: In all cases wheq removing the owner's
wheels, tires, and brake drums, use care to index mark
the brake drums to their respective wheel and tire assem-
blies so that they may be reinstalled in their original
positions.)
If the problem disappears, then concentrate on the
tire-and-wheel assemblies as' being the cause of the
problem, and hence proceed to Part b. If the problem
still occurs in the same manner as before, inspect brake
drums and/or rotors for unbalanced condition or body
mounts for failure or improper torque, since the tire-
and-wheel assemblies are obviously not at fault.
(2) If known good tire, wheel, and drum assemblies
are not available, place the car ona hoist orjack stand so
that the rear of the car is supported by the axle, and
remove the rear tire, wheel, and drum assemblies. Retest
the problem speed in the car under these conditions. If
the disturbance is still present at the problem speed, tires
are not the problem. If the disturbance cannot be dupli-
cated on the hoist, then the tire, wheel, and drum
assemblies were at fault and, hence, proceed to Step 3.
CAUTION: This procedure should never be
attempted on the driving (front) wheels of an
Eldorado. It is therefore necessary to use the sub-
stitution method on those vehicles.
(3) Reinstall original tires in their original positions
and balance all four tire, wheel, and drum assemblies.
Retest onthe road.
b. BalancingWheels, Tires, and Brake Drums
Many wheel balancers will adequately balance the
wheel-tire-brake drum assembly; however, it is the skill
of the operator that really counts. The operator must be
welltrained ontheequipment used.
c. Checking Tire, Wheel Brake
Rotor and Rear Axle Runout
Excessive runout will cause a vibration which is
exactly like unbalanced wheels and tires. After balancing
tires, if a 1st order tire disturbance still exists, check
runout as follows:
1. Wheel and Tire Runout
Follow procedure described in Section 10,Note 10c.
If the runout cannot be reduced toacceptable values by
repositioning the tire and wheel, replace the parts at
fault. Retest onthe road.

0-16 GENERAL INFORMATION, MAINTENANCE AND LUBRICATION
2. Brake Rotorand Axle Shaft Runout
a. If after checking wheel runout (radial and
lateral), it is determined that excessive runout is present,
check brake rotor or axle shaft for runout with a dial
indicator before replacing wheel. Refer to Section 5,
Note 15 for specifications on rotor runout. Axle flange
runout should be less than .006 inch.
b. If lateral (in-out) wheel runout (wobble) is
beyond specifications, check brake drum to wheel pads
(front end) or axle flange (rear end) for lateral runout.
The dial indicator stem should contact the axle flange or
drum pads as close as possible to the outboard side of
the studs.
d. Tire Radial Force Variation
If the disturbance is still present, the problem is due
to a non-uniformity in one or more of the tires. This
fault is inherent
in the tire and often cannot be cor-
rected by any means other than replacement. The
problem which remains at this point, however, is to
isolate the offending tire(s). This may be accomplished
by using a machine capable of measuring loaded radial
runout. See Section 10, Note 9.
5. Torque Sensitive and Car Speed Sensitive
The only excitation which is both car speed sensitive
and torque sensitive is 2ncl Order driveline (two vibra-
tions per revolution) on the "C" car or 3rd Order Drive-
line (three vibrations per revolution) op the Eldorado.
These problems are caused by improper drive shaft
angles which are a result of wrong standing height or
faulty joints. Refer to Section 3, Note 1 or 18to check
standing height. Drive axlejoint replacement is described
in Section 3, Notes 35 and 36. Constant velocity univer-
saljoint repair is described in Section 4.
6. Torque Sensitiveand Engine
Speed Sensitive
The only excitation which is both engine speed sen-
sitive and torque sensitiveis the "firing order" excitation
(that is, 4th Order for an eight cylinder engine). The
problems likely to be encountered in this class are as
follows:
a. An engine-driven accessory (power steering
pump, generator, air conditioning compressor, etc.) ex-
cited by 4th Order Engine.
Engine driven accessories generally do
not present a
problem if all attachment bolts are torqued tospecifica-
tions and all drive belts are adjusted to the proper ten-
sion. Hence, in order to verify that an engine-driven ac-
cessory is not the cause of a vibration complaint:
b. Check installation torques on all attachment
bolts securing either an accessory to its mounting or the
mounting to the engine.
c. Check all drive belts for correct tension. Also
check the physical condition of the belts.
d. Visually inspect each accessory to ensure that
the bracketing installed is complete and properly as-
sembled.
e. The checks outlined above should be performed
and any irregularities corrected before proceeding.
f. Power plant "bending" as excited by 4th Order
Engine.
(1) Loosen the top four bolts which attach the trans-
mission to the engine, and reappraise the problem. If this
is the actual cause of the complaint, the problem should
now occur at a much lower-engine speed than it did
originally, or be completely eliminated. Retorque bolts
before proceeding.
(2) Having thus verified that this is the actual cause
of the complaint, the following procedures are suggested
as a means of correction:
(3) Inspect the vehicle to be sure the entire engine-
transmission assembly and the exhaust system are not in
contact with the frame or body:
(4) Inspect the engine and transmission mounts to
be sure they have not sagged, failed, or been distorted.
(5) Check the initial spark advance setting.
(6) If these inspection procedures reveal any irregu-
larities, correct and retest on the road.
g. Exhaust system "bending" as excited by 4th
Order Engine. (This may include either the crossover
pipe, exhaust pipe, or tailpipe.)
CAUTION: It is often convenient to test for
exhaust system vibrations by stalling theengine in
Drive with the brakes applied. However, a car
should
never be stalled at engine speeds greater
than 1200-1300
RPM and Erfor extended
periods of time, since the transmission may over-
heat. Whenthis method oftestingis used, it is best
done on a hoist, permitting the driveline and rear
axle to rotate a.fter each appraisal to circulate
transmission oil. DO not use'ihis test method for
anv uroblemoccurinnabove 1300
RPM.
When a particular component of the exhaust system,
such as the exhaust pipe or tailpipe, is suspected of
causing a vibration problem, it may be verified by the
following procedure:
(1) Put the car on a hoist with a helper behind the
wheel and all doors and windows closed. Next, stall the
vehicle in "Drive" as described above in the problem
RPM range, while pressing a metal object (such as a
wrench or screwdriver) lightly against the suspected
component. If this component is the cause, it will
"buzz" or "rattle" against the wrench or screwdriverdue
to its vibratory motion.
(2) To further verify that the suspected component
is the cause, pull down rather heavily on that component
while the driver evaluates the problem
RPM range for
any reduction in the level of the disturbance. This
method of verification may also be applied on a road
test by clamping a 5-10 lb. metal weight securely to the
suspected component. Such a weight will change the
resonant frequency of the component in question, and
hence will change the problem speed if it is actually the
cause.
(3) To verify disturbances produced by exhaust
system components which resonate beyond 1300 RPM
(such as the exhaust crossover), the stall technique
cannot be used. In these cases, it is best to use the
weight-and-clamp method together with a road test.
Having verified that some component of the exhaust