Allis-Chalmers HD 6B User manual

Topic Title
Page
Air Pre-Cleaner and Air Cleaner .......... 42
Avoid Unnecessary Engine Idling .......... 17
Cold Weather Engine Primer .............. 44
Cold Weather Operation ................. 19
Driving Instructions . . . . . . . . . . . . . . . . . . . . . 17
Electrical System ·. . . . . . . . . . . . . . . . . . . . . . . 40
Engine Clutch and Clutch Brake . . . . . . . . . . . . 51
Engine Control Adjustments . . . . . . . . . . . . . . . 49
Engine Cooling System .' . . . . . . . . . . . . . . . . . 20
Engine Lubrication Syste.m· .......•....... 36
Fuel Storage .......... , ............. ·. . 9
I •
Fuel System~ ............... ~ . . . . . . . . . . . 22
General Description . . . . . . . . . . . . . . . . . . . . 4
General Specifications . . . . . . . . . . . . . . . . . . 5
-Governor ...................... :.. . . . . . 34
Operating C~~trols and Instruments . -~ . . . . . . 13
Operating in Mud or Water ; . . . . . . . . . . . . . 19
Periodic Adjustment . . . . . . . . . . . . . . . . . . . . . 11
Periodic Lubrication· and Preventive
Maintenance ........................ 10
Topic . Tit.le
Periodic Service ....................... .
Preparation of Tractor for Storage ....... \ .·
Preparation of Tractor for Use .......... : .
Routine Service .......................•
10-Hour Service ................... .
100.Hour Service ................... .
200-Hour Service ................... .
400-Hour Service
1000-Hour Service ................... .
Speciflcaflons of Fu.el .................... .
Specifl~ations of Lubricants .............. .
StartintJ and Stopping of Engine .......... .
Steering Brakes ..... ,. ................. .
Steering Clutches ...................... .
T.-ack and Traek: l~ler Adjustment ........... :
Tractor and Engine Serial Numper ....... ··
Valve Adjustment and Cylinder Head ... el(·· ••

The/,Model "HD 68" Tractor is a 12,400 pound track·type tractor p~,'l,(ered with a
:f'~ylinder, 4 cycle "DIESEL" engine.
Power from the engine is transmitted' through a single plate, over-,center type ,engine
clutch to the transmission through q universal ;oint drive shaft assembly. From the trans·
mission the power is transmitted to the bevel gear and from fhe bevel gear through the ·
steering clutches to the final drives and the track driv!,! ·sprockefs.
The transmission provides 5 forward speeds ranging from 1.5 M.P.H. in low gear to
5.5 M.P.H. in high gear and a reverse speed of 2.0 M.P.H., under full governed e,n9ine
speed of i800 R.P.M. ·
Mechanical self.energizing brakes, wide operator's seat, and uno8structed view of the
front of both tracks assure ea$y, positive contro.l of the tractor at all times.
The standard model tractor is equipped with 24-volt electric starting and light equipment,
suction type cooling fan, muffler, full width crankcase guard, bumper, hinged.radiator
guard, and 13° grouser track shpes. The truck wheels, track idlers, and track support
rollers have positive type seals.
TRACK
RHEASE
YOKli
AIR PRE-CLEANER
TRUCK WHEEL
OUTER GUARD.
(SPECIAL· EQUIPMENT)
TRUCK WHEEL
INNER GUARD
(SPECIAL EQUIPMENT)
c.1------------------------ Model HD 68 Tractor -----------------
FIG. 1

~'GcEJ~ ER A L/ ·SP E,C:l fI G.~,T l;,G>;N'Sir .
(STANDARD TRACTOR)
General Dimensions and Weight:
Overall Length ... , ..........•. x .•..... 10ft. 73<6 in.
Overall Height (to top of exhaust stgck) .... 5 ft. 8% in.
Overall Width (standard shoes) .......... ,6 ft. 63.4 in.
Ground Clearance ........................ 111,4 in.
Drawbar Height (c:enter fine of jaw) ...... , .. 131 ~6 in.
Lateral Drawbar Movement .....•............ 21 in.
Shipping Weight (approximate) ... · ....... 12,400 lbs.
Tracks:
Width of Standard Track Shoes ............... 13 in.
Maximum Width Track Shoes Available ......... 20 jn.
Tread Wid.th (center-to-center) ................. 60 in.
Engine:
Make· ...................... "Allis-Chalmers" Diesel
Model .................................. HD-344
Type ............................ .4 Strol<e Cycle
(Naturally Aspirated)
Number of Cylinders ............................ 4
Bore .........•............................ 4K6 in.
Stroke ........ · ............................ 5'<6 in.
·Crankshaft Rotation (when viewed
from fan end) ........................ Clockwise
Number of Main Bearings ... , .............. · ..... 5
Piston Displacement .................... 344 cu. in.
L"ubrication ...........................•.. ··•. Pressure
Fuel Used ............... , .............. Diesel Fuel
Fuel Supplied By .. "American Bosch" Fuel Injection Pump
Low Idle Speed .................. 525 to"J50 R.P.M!+
High Idle Speed ............. 1930 R.P.M. +or -25
Governed at Full Load ................. 1800 R.P.M.
Steering:
,,.I}-.•
Method .............. .- ..••................ Clute
Controls, ...................• , ......... Mechanical
Turning Radius ............................ 8414Jn.
Capacities (Approximate):
(U. S. Standard Measure)
Cooling System .......................... 6~ gal:.'
Crankcase and Filter .....•................ 2~ gal~;
Air Cleaner ........................... : ..... 2 qts.
Transmission ................ ; ...•........ .5 gpj~.
Final Drives (each) ......................... 3,~(:t\
Fuel Tank .............................. . 40 >'v· ·
Support Roller (each) (Grease) .............. , ;
Truck Wheel (each) (Grease) ...............•. ·
. Track Idler (each) (Grease) .......•......... 11
Speeds ( at Rated
Engine Speed):
1st Gear ................ .
2nd Gear ................ .
3rd Gear ................ .
.4th Gear ................ .
5th Gear ................ .
1st Reversp .............. .
2nd Reverse. ; ............ .
HD6B
l.5M.l~.
2.4M.P.H.
3.3M.P.H.
4.0M.P.H.
5.5 M.P.H.
2.0M:P.H.
The Allis-Chalmers Manufacturing. Company reserves the r,ieht to make changes in the
above specifications or to add improvements at· any time without notice or obligation.

TRACT(!)R A,ND ENGINE SP.IAL NU,MBERS
1~11 all parts orders and in all correspondence
'relatiy,e/to the tractor, it is necessary that both
,<;)*t
1
fractor and engine serial numbers be given.
;:ff{is will properly identify the particular tractor
and will assure obtaining the correct replacement
pq,rts f'?r it.
6
The tractor serial number is stamped in the rear
face of the steering ~lµtch housing (near the upper
right corner) and is also stamped , on a serial
number plate attached to the cowl.
The engine serial number is stamped on a plate
attached to the left rear side of the cylinder block.
FIG. 3

SPECIFICATIONS Of LUBRICANTS
A. Engine Crankcase Lubricant
USE NON-CORROSIVE "DIESEL" ENGINE LUBRI-
CATING OIL CONlAINING ADDITIVES WHICH
WILL PREVENT SLUDGE OR GUM DEPOSITS.
UNDER NO CIRCUMSTANCES SHOULD A CORRO-
SIVE ENGINE LUBRICA "J:ING OIL EVER BE USED.
Use oils of the following viscosities:
Atmospheric
Temperature
Viscosity
90° F. and above
Use
SAE 40
32° F. to 90° F. Use
SAE 30
0° F. to 32° F.
Use
SAE 20W
0° F. and below Use
SAE lOW
Manufacturers of lubricants recognize the im-
portance of the qualities required for use in our
equipment and they are cooperating fully to assure
the use of only those oils which fulfill these require-
ments. The oil distributor and oil manufacturer
are to be held respo11sible for the results obta.ined
from their products.
The outstanding lubricating requirements for effi-
cient operation of the engine are: The maintaining
of piston rings in a clean, free condition; absence
of hard carbon and "varnish" deposits on or within
engine parts; the prevention of bearing corrosion;
and the promotion of general cleanliness within
the engine.
Proper operation and maintenance of the engine
are necessary to 9J,tain the desired results fro11J the
lubricating oil. fr/
(l
7
B. Air Cleaner
Use the same viscosity oil in. the air cleaner as
used in the engine crankcase. CAUTION: Do not.
use an oil that foams.
C. transmission and Final Drive Lubricarit
Lubricate these assemblies with a good grade of
engine lubricating oil purchased from a repufoble
oil company.
Use oils of the following viscosities:
Atmospheric
Temper:ature
Above 32'\f ,,
32° F. and below
Viscosity
Use SAE 50
Use SAE 30
D. Truck Wheel, Track ldler,>an&:1 Tra /•
Support Roller Lubricant
Lubricate these assemblies with''g ,€1
been tested ond found satisfactorfi
Allis-Chalmers Manufacturing Company\,.
A revised list of approved greases is issuec:1
periodicplly. Ask your nearest "Allis-Chalmers"
authorized Dealer for the latest list.
E. Pressure Gun Lubricant
Use a ball and roller bearing lubricant with a
minimum melting point of 300° ,F; This lubricaht
should have a viscosity range so clito assure e~sy
handling in the lubricating gun at the prevailing
atmospheric temperature, and MUST be water-
proof.

SPECIFICATIONS OF FUil
'Mr·
The '!OIESEL
11
fuel should be a natural distillate
~fr:oleum oil and must have certain qualities in
"brder to ignite and burn at the proper rate and
temperature. Field experience has ·shown that the
fuel best suited for this engine closely approxi-
mates the following specifications:
Gravity API ....................... 30 -35
Viscosity Saybolt Universal at l00° F ... 35 - 40
Flash Point ....................... 150° F.
Diesel Index .................. 48.5 to 65.5
Cetane Number ... ; .............. 46 to 60
Pour Point ......................... 0° F.
Volatil-ity 90% ............... 650° F. Max.
End Point 98%
Summer ................... 700° F. Max.
Winter ...... , ........ 600° F. Preferable
Sediment and Water ....... ~ ......... Trace
Ash , . . . . . . . . . . . . . . . . . . . . .02 of l % Max.
':,•Geriradson Corban .........• 03 of l % Max.
},C~o)phur .............. ; . . . V2 of l % Max.
satisfactory fuel flow through lines' and filters
. celd weather, the pour point of the fuel must
fie. at least 10° F. below the prevailing atmos-
;fJ:iie API ;gr'°vity of a fuel varies with its specific
gravity. The low API fuels are desirable because
they have a high specific gravity and more heat
·units per gallon. H9wever~ 4 ''the higher the API
gravity, the better will be. th~ ignition quality of
the fuel.
'The ignition quality of a fuel is expressed as; a •
"cetane number." The higher the cefone number,
the higher the quality of the fuel. The higher cetane
. .
fuel shortens the ignition delay period to facilitate
starting and improve combustion. The "DIESEL"
index number, which is a close approximation of
the cetane number, is a field method to represent
ignition quality. ·
The distillation 90% point and the end point are
important. High volatility is ~equired to enable
complete vaporization of the fuel, clean combus-
tion, and low residue formation.
The flash point of a fuel has no quality significance,
but is importcmt with respect to safety in storage
and handling of the fuel.
It is important that the fuel be within the specified
limits for ash, carbon, water, and sediment con-
tent, etc., to prevent excessive wear and damage
to engine parts.
It is also important that the fuel has lubricating
properties so that the fuel injection pump and fuel
nozzles are adequately lubricated. At times it may
be necessary to use fuel with no lubricating prop~
erties. If this occasion arises, add one quart of
SAE lO engine oil to every 10 gallons of fuel.
NOTE: Distillates should be used only in emer:
gencies. When the proper fuel is again available,
the fuel system must be drained and cleaned before
the proper fuel is added.
CAUTION: The sulphur content of "DIESEL" fuel
should be as low as possible. The fuel should not
contain a sulphur content of more than V:z of 1 %.
Generally speaking, a No. 2 "DIESEL" fuel pur-
chased from a reputable oil company will meet
the above specifications.

ll
fillers cmd eventi;,:i!iy dicm10£1•::e
i;:mmi,
p,oi·t,01bl,:1 ston:ige provid1:ts th,e meth:iJd
51i0,rin91 fu,e! cm the job, in Sl.lch c, i'cmk, th,e
c1r,d VJ'Cfl·er .:r)m easi"y be
ccm be pumped in1o th,e tn.:ictor fo3! lomk ¥ti~h ·
ne,;:ires'!·
this ty,p,e
OCCU!I" 111

PERIODIC LUBRICATION AND PREVENTIVE MA1NTENANCE
LubricaJion is an essential part' of preventive main- .
ten~u{ce, _controlling to a great extent the useful
life of the tractor. Different lubricants are needed
and some components in the tractor require more
frequent lubrication than others. Therefore, it is
important that lhe instructions regarding types of
lubricants .and the frequency of their application,
as given in this manual and on the "LUBRICATION
CHART," be explicitly followed. Periodic lubrication
of the moving parts reduces to a minimum the
possibility of mechanical failures.
To prevent minor irregularities from developing
10
into serious conditions that might involve shut-
down and major repair, several other services are
recommended for the same intervals as the periodic
lubrication. The purpose of these services or in-
spections, which require only a few minutes, is to
assure the uninterrupted operation of the tractor
by revealing the need for adjustment caused by
normal wear. The need for some minor adjustment,
if neglected, could result in failure and shut-down.
Refer to the "LUBRICATION CHART" for relative
location of the service points of the tractor to be
serviced.

For added conveniente, listed below are the lubri-
cation points, adjustments, service items, and in-
spections to be made at each of the intervals (10-
l 00 - 200 - 400 - 1000 hours) shown on the
"LUBRICATION CHART." Reference symbols given
below refer to those given on this chart.
10-HOUR SERVICE
(Identified by Q on chart)
INSPECT:
Engine Crankcase -Oil Level
Air Cleaner Oil Cup -Oil Level
Air Pre-Cleaner -Dust Level
Radiator - Coolant .Level
Batteries -Check Electrolyte Level
SERVICE:
Fuel Filters
First Stage -Drain Sediment
Second Stage -Drain Sediment
Fuel Tank -Check Fuel Level and
Drain Sediment
LUB:a'UCA'IE:
Engine Clutch Shifting Bearing
100-HOUR S~RVICE
(ldentilied by O on chart) ·
INSPECT:
Final ·Qrives -Oil Level
Tr(msmission -Oil Level
SER~CE:
Engine Crankcase - Change Oil
Lubricating Oil Filter -Replace Element
Batteries -Test with Hydrometer
LUBRICATE:
Engine .Clutch Shaft Rear Bearing
Engine Clutch Camshafts f'Rockford" Clutch
only)
Engine qutch Shifting Sleeve
200-HOUR SERVICE
(Identified by • on chart)
LUBRICATE:
Fan Idler Bearings
Fan Bearings
Generator
Brake Pedal Levers
400-HOUR SERVICE
(Identified by O on chart)
LUBRICATE:,.
Drive Shaft Universal Joints
. 1000-HOUR SERVICE
(Identified by • on chart)
LUBRICATE:
Truck Wheels
Truck Idlers
Track Support Rollers
SERVICE:
Transmission - Change Oil
Final Drives - Change Oil
PERIODIC SERVICE
Fuel Filters -Replace Elements
Cooling System -Drain and Flush
Fuel Tank -Drain and Flush
PERIODIC ADJUSTMENT
Eg.gine Clutch -Check and Adjust
Steering Clutch Linkage -Check and Adjust
Brakes -Check and Adjust
Tracks -Check .and Adjust
Water Pump and Generator Belt -Check and
Adjust
· Fan Belts -Check and Adjust
Valve Tappet Clearance -Chec:k and A:qJlist
Fuel Nozzles .:.... Check and Adjust ·· ,•
11

Cl· cornp;'E:i)·lf;}
sure·· ·~·J"~oiJ no
Ihe fr::,do,r i'o make
lo:i:!' or
m
the 1&nkr.mce or
the 1:m Ihe engirie
soft w,.~rr,er or c1 suit,c,b;e cmti-fre,,eze
'l'c,
lri !'h1::e Clip is
(~ir prs=
firi::ici'or m, i!'s
f'rCi1Cdk3 Vl·/2'1'..;~,. p·:Jri~]0:5f~ly
()p,c!n.1,t12, the fr1::i1c:i'or with r,] i !9ht
hmirs. The mo:£,!' ,edlld0nt e•nr::3ini:':,
un1oi::1dinr1
rrw.st
T t~7~ /.c\, (~' /(
cil:iirr,iin1ed i'h<:i ii:ln91in,r.1 terr,1~1,e1,,1hm:1
ci n:mge 'ii Jo ·i i:35° F, Op:::'!rrcrtinti the
,rmgine th(.;; ,c,,:,•;)l,i::;ITTri· temp"rcrl·urfi hr:'ilov'I' iihis
rcm,ge vviil rr~svit irn:::011npleh::1 ·co,mbuz;'l'r,:,n
stud :1r._rts
dwck
hcmrs, th•e,
,::mk:rging th,~: bolt
c!uti:!1
If
propet ton:pe, it is cibci to t1v2,
vi:..iive lapp,ets for proper ,deGn:mc,e (n?.fo:r
"\/Al VIE AD.HJSTMJ:],fl' Ah!D CYUl',IDER HEAD"
fcH· ;nk1,:-rn,r:i;!,km).

The
1N!'ih
~, !En{ijhlle ~i~'IDilJrtr~(JHY
knob is
Th,e
shvt-oH
sh1.ri·"ciff
en,;1 inri h; to ,:1h::1rireJd; puU ·~ht~
nor sf'eip the
fo idling
to :;Jop 'l'hei 1,mgir,e, C,~,UTiOl··,l: D,o
firs, the
1
Itfo1!![ll~ll1).s, Cfotdr fJ~:J;,e:r,~i1l'~E'itl le~,e~·, Thi'.:! 12::;1~
g,iru~ ckrN::h op
1
en:rling ,engine
dutch frcin, the tH·,9drue ti:,
~jGC!ir rr:;rt·fio: ,,
posi'fo:m h:, '>.ii/hid,
·~h,,~
V\/h,;;;n the dutch
en,gc1gc:~ dutch., H
pc.:i5i~·fc1in
'I"rr:J ns1Yt~fl;si()I~
1Q
. Th,~
1:!11fJl11e dutch op1a:n:::rl°ing 1rmsr io,r"' n·ii:]ved 'frr::;.
rc
1
cs,Hion 1.x;,frw,re l'hE: 'lran~m1ss.1.o,r,r
ccm be n'ilC1Vf.:1d int,o or fo'h .. ,
(!!Kl'!h,E:f pt1srnc:m.
h·""'"'''"" stoppinJ;1. hvc,
'Which ccmnect the
'.'aL 31·,J·,rnfil
0
1l·,~a· (jl11f.l:{~~·t:irtim1f] Ritn.t. Pt!!:.h on s.',',r::irl'er
op15•ra1ing n:,d IfJ en,i;tClf!®' s'tc1rt1Br pinkm the,
fly11vhe,e: ring :;iecff to nperc:1te the starter
1im,~
,:iep,r,es:s,ed it musl"
j'.'/OSIIk;,11
Hme Io ieec1s'E:1
stmter open:tlfog rod is
b1:; rrJs,ad, cmd ·wm
no'l thc1 Z:n(Jirn:!,. (\lC1 TE: H fhe engine rfo,es
dt;ihI,hand
turn;
'l"rc1ck dr;ve, spn)ckets.
sh:.w?r1t1£1 l,&·rer bc1d,;
!,::1H-hand r.leer!ng,
dis-
'lhe
t,i,) nDR'[V!hlG INSTRUCTli'.Ji!•;Su).
} , it'll:ak@ P,e,Jl1:.!~S. bn:ik1 3! pr~i::kllis r:11n? 1xsed
to H,1~ sp,?.,.:!'d or h:1 fru::ilH.i:1h:, i'rJrni:"'i{J the
turn ths trncJ·or t,,, ·~he rk:ihl',.
,.,
(~r:d

right brake pedal; to turn the tractor to the left,
fully disengage the left steering clutch and press
on the left brake pedal. After the desired turn has
been made, release the brake pedal and return
the steering lever to its fqrward position.
CAUTION: Never attempt to use the brakes to turn
the tractor without first pulling the steering lever
back as far as possible on the side toward which
the turn is to be made.
8. Parking Brake Lock Levers. The parking
brake lock levers provide a means of holding the
brake pedals in the applied position. To engage the
parking brake lock levers, depress the brake pedals
and move the lock levers forward. To disengage
the .parking brake lock levers, further depress the
brake pedals and move the lock levers toward
the ,rear.
FIG. 6
9. Cold Weather Engine Primer Dispenser.
The primer dispenser, located on the cowl (to the
right of-the instruments), is used to hold and to
puncture a capsule containing starting fluid used
as an aid in starting the engine in cbld weather.
1 O. Cold Weather Engine Primer Pump.
The primer pump, mounted in the cowl with the
instruments, is used to force starting fluid through
a small nozzle and into the air inlet elbow of the
engine. Refer to "STARTING OF ENGINE" for full
ins~ructions on the use of the Cold Weather Engine
·'.Primer Pump and Primer Dispenser.
11. .Light Switch. Move the switch lever to turn
on the lights. · · 14
B. INSTRUMENTS
1. Engine Temperature Gage. This gage
indicates the engine coolant operating tempera-
ture, which should be maintained between 160°
and 185° F. at· all times.
2. Engine Oil Pressure Gage. This indicates
the pressure at which the engine lubricating oil is
circulated through the engine. At full throttle, the
oil pressure should be between 30 and 55 pounds
at normal engine operating temperature (160° to
185° F.). CAUTION: If no oil pressure is indicated
by the gage, the engine must be stopped immedi-
ately and the cause determined and corrected.
3. Fuel Pressure Gage {Special Equipment).
This gage indicates the pressure at which the fuel
is circulated through the low pressure fuel system.
Under normal conditions, with the engine operating
at full governed speed, the fuel pressure should
be between 5 and 15 pounds.
4. Ammeter. The ammeter indicates the charg-
ing rate of the generator. When the batteries are
in a discharged condition, the ammeter should
indicate a good rate of charge until the batteries
approach a fully charged condition. When the
batteries are fully charged, the ammeter will indi-
cate nearly zero except for a short time after the
starter has been used.
5. Engine Hour Meter. The engine hour meter
is installed as special equipment.
All hands of the hour meter move clockwise. The
small indicator (upper left) visibly turns when the
meter is recording. The meter records up to l0,000
hours and repeats. The four figures of the hours of
operation are read from the three hands as follows:
l 9 5 5
Use number passed on 1,000 hour
(inner) track here -------...J
Use number passed on l 00 hour
(middle) track here---------J
Use number passed on lO hour
(outer) track here ·-------------l
Use number of marks passed beyond
last figure on 10 hour track here _____ __.

Engine Hour Meter ____ __.
(Reading- 1955 Hours}
FIG. 7
STARTING AND STOPPING OF ENGINE
A. Starting of Engine
1. Before starting the engine, check the fuel
level, crankcase oil level, and the level of
the water or anti-freeze solution in the cool-
ing system. If repairs have been made since
the last operating period, be sure that all
nuts and bolts affected by the repairs ·have
been tightened and the parts have been
properly adjusted.
2. Push the engine clutch operating lever for-
ward and move the transmission gear shift
lever to its.neutral position.
3. Push the engine shut-off knob all the way
forward (run position).
4. Pull the throttle operating lever all the way
back (high idle).
5. Press forward on the starter operating rod.
If the starter spins but does not crank. the
engine, pull the starter operating rod back
to its original position (all the way back) and
wait until the starter stops spinning before
depressing the rod again. CAUTION: If the
engine does not start within 30 seconds,
allow the starter to cool for 2 minutes before
using it again.
6. As soon asthe engine starts, pushthe thrott~e
operating lever forward enough to slow the
engine to about 1h of full speed and allow
the engine to warm up. CAUTION: Be sure
15
the engine clutch operating lever is in the
engaged position during the engine warm
up period~
7. Observe the engine lubricating oil ·pressur,~,
indicated by the gage. With the engine\r~n~ '
ning at full speed and with the er1gine: c:doi'.:'
ant at normal operating temperip(~re {l~Q.P:
to 185° F.), the oil pressuf@ .. should be bJi
tween ·30 and 55 pounds. If the'\. ofl is cotq,
no. pressure may be indicate~.J:>y the ga.e
for about 15 seco,nds after tf:ie'.i}ngine stal'fs,
but if the pressure does; not then rise to
normal or above, the engine must be stopped
immediately and the cause determined am:I.
corrected.
8. If the tractor is equipped with a fuel pressul:e
gage (Special Equipment), observe the fuel
pressure indicated by. the gage. With the
engine running at full speed, the fuel. pres-
sure should be between 5 and 15 pounds.
9. Move the throttle operating lever to obtain
the desired engine speed.
10. In cold weather, when it is necessary to use .
a starting aid in starting the engine, pi:oceed
as stated above in the first four (4) opera-
tions, then proceed as follows:
a. Unscrew the.upper chamber of theengine,,
primer dispenser.
b. Place a capsule of starti~g flui~, smciH

,..,,
or large, dependi~g upon the atmos-
pheric temperature and the requirements
established by trial, in the lower chamber
or body of the primer dispenser. In ex-
. tremely low temperatures, one large and
one small capsule may be necessary.
c. Pull the plunger to the top of the upper
chamber and screw the upper chamber
tightly onto the primer dispenser body.
d. Push the plunger to the bottom, thereby
puncturing the capsule and releasing the
starting fluid so it can be picked up by
the primer pump.
e. Push the engine shut-off knob all the way
forward (run position) and pull the throt-
tle operating lever all the way back (high
idle position).
f. Depress the starter operating rod to
crank the engine, and at the same time
~
operate the primer pump to force starting
.fluid into the engine air intake system.
Continue pumping, after the engine
starts, until all of the starting fluid in the
dispenser has been injected into the air
intake system. CAUTION: ALWAYS BE
SURE THE ST ARTER IS CRANKING THE
ENGINE BEFORE USING THE PRIMER
PUMP TO INJECT ST ART/NG FLUID INTO
THE ENGINE AIR INT AKE SYSTEM.
g. While the engine is warming up, unscrew
the upper chamber of the engine primer
dispenser, remove the empty capsule,
and reinstall the upper chamber.
CAUTION: The starting fluid contained in the cap-
sule is essentially ethyl ether, highly inflammable
16
af!d should be treatf!d with the same caution as
high octane gasoline. Gelatine capsules dissolve in
water and soften at high temperatures. Therefore,
the following precautions must be taken:
1. Avoid breathing large quantities of the
fumes from the starting fluid.
2. Avoid. cutting of the hand by barbs on the
~uncturing plunger.
3. Avoid proximity of the starting fluid and
capsules to open flames, sparks, or hot
surfaces.
4. Avoid contact of the. capsules with water.
5. Avoid subjection of the capsules to high
temperatures (above approximately 120° F.).
Obtain starting fluid capsules from your nearest
"Allis-Chalmers" Construction Machinery Dealer.
The capsules are packed, 12 of the 17 c.c. or
24 of the 7 c.c. sizes, in a can for safe storage
and handling. Obtain the size and quantity most
suitable for your needs according to the prevailing
atmospheric temperature.
B. Stopping of Engine
Push the throttle operating lever all the way for-
ward (low idle position) and allow the engine to
idle for at least 5 minutes, so that the engine may
cool gradually and uniformly, then pull the engine
shut-off knob all the way back to stop the engine.
IMPORTANT: ALWAYS SLOW THE ENGINE ·To
IDLING SPEED BEFORE PULLING THE ENGINE
SHUT-OFF KNOB TO STOP THE ENGINE. Cover
the exhaust pipe at the end of each day's operation
to prevent rain from entering while the tractor
is idle.

'II.
AVOID UNNECESSARY ENGINE IDLING
Prolonged engine idling causes the engine coolant
temperature to fall below the specified·operating
range of 160° to 185° F. Operating with the
coolant temperature below this range is detri-
mental to the engine, causing incomplete com-
bustion of fuel, which in turn causes crankcase
dilution and lacquer or gummy deposits ,to form
on valves, pistons, rings, etc. It also causes rapid
accumulation of sludge within the engine.
Since starting the engine is readily accomplished'
with an electric starter, there should be no reason
for prolonged engine idling. Stop the engine when
prolonged idling periods are necessary.
DRIVING INSTRUCTIONS
A. Starting of Tractor
Start the engine and allow it to warm up, then
slow the engine to idling speed. If the engine
clutch has been engaged, disengage it and push
forward on the clutch operating lever to force the
clutch brake facing against the brake disc, thus
stopping the rotation of the transmission input
shaft. Move the transmission gear shift lever into .
the required position· for the desired speed or
power. Pull the throttle operating lever about half-
way back and pull back steadily on the engine
clutch operating lever until all slack is taken up ·
between the tractor and the load, then pull the
lever back quickly to fully engage the clutch. After
the engine clutch is engaged, move the throttle
operating lever to meet the operating requirements.
Engagement of the engin~ clutch with the engine
running at half throttle and starting the load in the
above manner will prevent excessi.ye slippage of
the clutch, thus prolonging clutch life. It will also
prevent "shock loading" the tractor.
To shift to another speed range, push the engine
clutch operating lever forward and shift for the
desired speed or power. When the engine clutch
operating lever is pushed forward it forces the
clutch brake facing against the brake disc, thus
stopping the rotation of the transmission input shaft.
Stopping the input shaft rotation enables the
operator to shift without clashing the gears.
To shift to a higher gear after the tractor is in
motion, push the throttle operating lever forward
to the idle position and disengage the engine
clutch. At the same time, shift to the higher gear,
engage the engine clutch, and pull the throttle
lever back to obtain the desired speed.
The engine dutch operating. lever controls the
engine clutch which transmits power from the en-
gine to the transmission. Push the lever forward
to disengage the clutch; pull it back to engage the
clutch. The clutch operating lever also actuates a
shifting shaft locking device in the transmission.
When the clutch'operating lever is pulled back to
engage the engine clutch it locks the transmission
"' shifting shafts in the position to which they have
been moved by the transmission gear shift lever.
The clutch operating .Jever must be moved tci
disengaged position before the transmission :~ .
shift lever can be moved to shift the gears i~
neutral or into another position. '
Satisfactory and efficient ·operatron depends
largely on the operator's judgment in selecting .the
proper gear ratio and speed for the various loads
or operation. Always operate the tractor in the
speed range that will permit the engine to operate
at full speed. This /will not only assure the most
power from the engine but will also allow the
engine to operate at its highest efficiency.
CAUTION: DO NOT SLIP THE ENGINE CLUTCH
IN AN EFFORT TO PULL AN OVERLOAD; SHIFT
TO A LOWER GEAR.
The engine clutch should engage with a definite
over-center "snap" and should require an appre-
ciable pull on the operating lever for its engage-
ment. If this "snap" is not evident, or if the clutch
slips when under a load, adjustment must be made
immediately (refer to "ENGINE CLUTCH ADJUST-
MENT").
B. Steering of Tractor
The tractor is steered by disengaging the steering
clutch on the side of the tractor toward which the
turn is to be made. This is do~e by using the steer-
.17

/
ing levers 101.ated directly in front of the tiperator.
To mcike a right turn, puU ,back the righ,t-hand
ste,efing lever; to make a left turn, pull back
.~the left-hand steering lever. With the left steering
0
dutch disengaged, power is not delivered to the
, left track and the track ~ill ·slow down or stop.
Since power is still being delivered to the right
track, the right track. will keep turning and cause
the tractor to turn to the left. When the right
steering dutch is disengaged, the tractor will turn
to the right in a similar manner.
If a short turn is to be made, pull the steering
lever back on the side toward which the turn is to
be made and press down on the corresponding
brake pedal; this will stop the track completely.
Always pull the steering lever all the way back
when turning. When the tractor .has turned as
desired, return the lever immediat"ely to its forward
'position. Disengage and engage the steering
dutc;:h~st,smoothly and completely to avoid exces-
···•· f?siv.el·~ar on the dutch friction discs.
~;,' ;':{ '} '\)):/£'£:!:, ':
; '>" ,J.''(:,' ,:,'4'.11
,:~:~~ti;steerfog the tractor dc;,wn steep grades with
.the lpqd pushing·the tractor, the use of the steer-
.ing levers is opposite to that when pulling a load.
lh this case, the left-hand steering lever is used to
mak,1a iright twrn and the right-hand steering lever
to make a left torn. Disengaging either steering
dutch wiU allow the track on that side to travel
faster, since the br.aking ,power of the engine is
released from it, while the steering dutch remain-
ing engaged will ad as a. brake for the opposite
.track.
During operation, observe the amount of free travel
of the steering levers (the distance the levers move
before pressure is felt and disengagemenf of dutch
begins). This free travel,. which assures complete
engagement of the steering dutches, should be
from l to 3 inches, measured at the tops of the
levers, When'the free travel of either steering lever
becomes less than l inch, the steering dutch linkc;1ge
requires adjustment (refer to "STEERING CLUTCH
LINKAGE ADJUSTMENT").
C. Stopping of Tractor
To stop the tractor, push the throttle operating
lever forward and disengage the engine dutch by
pushing the dutch operating lever forward, then
press on the brake pedals to apply the brakes. If
the tractor is parked on a grade where there is a
possibility of its rolling, lock the brake pedals in
their applied position by the use of the parking
brake lock levers. Allow the engine to idle at least
5 minutes so that the engine will cool gradually
and uniformly, then pull the engine shut-off knob
all the way back to stop the engine.
IMPORTANT: ALWAYS STOP THE ENGINE WHEN
PROLONGED IDLING PERIODS ARE NECESSARY.
This will not only save fuel and unnecessary wear
on the engine but will also avoid operating the
engine below normal operating temperature. If it
is necessary to keep the engine running, it.should
be run at a speed fast enough to maintain normal
engine oil and fuel pressure and with the engine
dutch engaged.
While operating the tractor, observe the action of
the b.rakes. The brakes are properly adjusted when
the brake pedals each have approximately l% to
2 inches of free travel (refer to "STEERING
BRAKES"). The brakes require adjustment before
they become loose enough to allow the brake
pedals to strike the floor plate when the brakes
. are fully applied. If the brakes are properly ad-
justed, and still do not hold, it may be due to oil
on the brake linings and the brakes will require
washing. Refer to "WASHING STEERING
CLUTCHES" for instructions on washing the brakes
and steering dutches.
18

The slee1dni.:1, ·
ceimp1:irtmerrb, cire
dn::iino!:Je ,,;:,,f i:::my
h,,ies
or· wah':':i". /~1; si·eering diJ,tch compartme1r11t
cfrc1in hole (Fig. 52) is !oo::ited fr, th,a boHom of
dutch cornpo;rtmen't.
The en•f1ine
rrienl' cmd 1s
l",l',,"!i''IC•i"ii in the bofh::itn ,:,f "tl1•8
cm
(r0fr1r to
hc,s1~~s
'io pn:rJ·ecil' lt frnffi
SYST!c':1\i\
1
').
und
-:md r9,.
T1::isi· pr,epc::1n2: ''C()LD VV'E:ATHEl;i: ENG!l,,iE
Pml,/lE!l'" for tD50 CJS Sf)IXJ CIS
indk,::r[·t'H,
ri!:iqi,iired. Prrovide, c1
rcidk~l·ot
(:,c::;rnpciri·nr,ent H the
to mc1iurhc1in i·he ,?n~
tr:crnnpernh.ir,a, 'Ntthin ths
cmd fr,r sides o-f t!H':,
th1srir1os"!"u1"tr,.
gr,nie
rr.mge
e,i:framdy dusty l), scmdy ci:::inditi::mz,
1/~
dro1n p!VfJS with lrc1d,cir) shou,ld be
V1 lhen ,o,p.ercrhn£i wiih th~ drciin plug:ii im;tcdiad,
n,Hno·,i1,::i Ih,e piug.s to ,oi! Hm,·
,:1ccunmk:1ied in
it from getl'ing on
brc;ke lining:s .. if '!'he l'n'.:l,dC1l" ren1ahls idki c.1'!'
ge:o,d pi·'(1:Ct2it:E~ t,(), r1B:tT)
1
0,\1
1e
'!he d1J)' reinstc1l1
tn::1ctc,u' the mn,t
t,kir'l'ing 1:Jif c1 "DIESEL" ,1:HJ1Jim'<
lTH,::rn,s cc:m be d::rhJ11n~d
sp,aec!,
bcdt,edeis, :,h::1ri"'2,r,
open:rted in
y1r:,1JJ r nta(~ lft85'·t 1t:11 tJth ,c:1(li.1..:ed t
11
~'°
for !nform.::iticm1 rEJl}mdintJ o::ivciik,,,
fhe ope·rofin;\Ji
Nhiffe frm:for is idle,
sr...ffidiy f.'J ihe gn:nm,d,
or fr·,adrs,
ccruss:d by cm ,,:,iff&mpf 1c,
trnci<s.

ENGINE COOLING SYSTEM
A. Qp~,ription of System
The engine cooling system includes the water pump,
radiator, engine oil cooler, thermostats, engine
temperature gage, cooling fan, and the water
passages in the cylinder block and cylinder head.
The water pump draws the coolant from the bottom
of the radiator and circulates it through the engine
oil cooler and through the water passages in the
engine. The coolant is discharged from the cylinder
head into the water outlet manifold and passes
througn' the thermostat housing and the radiator
inlet elbow to the upper part of the radiator. The
fOolant is cooled as .it passes from the top to the
bottom,of the radiator core by air drawn through
\h~ radiator co.re by the suction-type cooling fan.
Th,~ th~ric1nristats, located in the thermostat housing
t.if the front of the water outlet manifold of the
engine, operate automatically to maintain a normal
coo.lant operating temperature of 160° to 185° F.
'B. General Maintenance
Jn warm weather, keep the cooling system filled
with dean sofrwater or rain water whenever pos-
sibie.''llf softw!!iler is not available and hard water
must be used, tire hard water should first be treated
with a water softener. A commercially reliable rust
inhibitor should be added to the cooling system for
warm weather operation. A rust inhibitor (soluble
oil), available in half pint or quart containers, can
be ol:itained from "Allis-Chalmers" Dealers and
should He added to the cooling system in propor-
tions of 1·pint of soluble oil to every 15 quarts of
water. C!>,UTION: NEVER ADD AN ANTI-FREEZE
SOLUTION TO A COOLING SYSTEM THAT CON-
TA/NS A RUST INHIBITOR. Drain, flush, and refill
the cooling system with clean water before adding
an anti-freeze solution for cold weather operation.
In winter weather, use an ethylene glycol anti-
freeze solution in the system to protect against
damqge from freezing. This type of anti-freeze has
a much higher boiling point than water. After any
addition of water or anti-freeze compound, test the
solution after the added quantity has become
thoroughly mixed to make sure it will withstand
the prevailing or anticipated temperature. A mix-
ture of 60% ethylene glycol and 40% water will
20
provide maximum protection; the use of more than
60% ethylene glycol in the solution will raise the
freezing point and provide less protection against
freezing.
Keep the radiator air passages free from leaves,
trash, and other material which will restrict the flow
of air through the radiator.
All leaks in the cooling system must be corrected
as soon as they are evident. The fan drive. belts
and the water pump and generator drive belt must
be kept properly adjusted.
The most efficient engine operation is obtained
with the coolant operating temperature held within
a range of 160° to. 185° F. Operating the engine
with the coolant temperature below this range will
result in incomplete combustion of fuel, higher fuel
consumption with less power, and will cause harm-
ful deposits within the engine.
Maintaining the normal coolant op~rating tem-
perature (160° to 185° F.) depends mostly on
proper functioning of the thermostats. If the coolant
te,;,perature remains consistently below normal,
the thermostats should be removed, checked for
proper operation, and replaced if neces;;ary.
C. Draining of Cooling System
Remove the radiator filler cap and open the cyl-
inder block drain cock, located on the right rear
side of the cylinder block. Open the radiator drain
cock, using the extension tool (included with 'the
tools fur~ished with the tractor) inserted through
the hole in the lower right corner of the main frame.
CAUTION: When draining the cooling system in
freezing weather, make certain that the coolant
flows freely from all drain cocks and that the
system drains completely.
D. Filling of Cooling System
Close the radiator drain cock, located at the lower
right corner of the radiator (in the water outlet
elbow). Close the cylinder block drain cock, located
in the right rear side of the cylinder block. Fill the
cooling system through the radiator filler cap
opening until the coolant level is within approxi-

Cylinder B.lock Drain ~q~/$ ~1',J Radi~tor
Drain Cock location.
FIG. 8
FIG. 9
mately 2 inches of the top of the radiator and
install the radiator filler cap.'
E. Fc~an Drive Belt Adiustment
The fan drive belts are correctly adjustic:1 when
the straight side of the belts can be pressed inward
by hand approximately Y2 to % inch at a point
half-way between the crankshaft and the fan
. 21
~=;;..: Water Pump and Generator Drive Self
· Adjustment foc~tion
FIG. 10
pulleys. To adjust the drive bE!lts1 loosen. th
idler bracket clamping capscre~."~'J-\9~en the
nut on the adjusting screw and turn/lf~:~:adj.ust ....
screw in or out as necessary to obtain'.fli}c;_orr~c:t
tension on the drive belts, then tighte~;tthti.fifdjost-
ing screw jam nut. Tighten the .. fall idJiji'li btfu9~1et
clamping capscrew.
F. Water Pump and Genercator Dri e
Belt Adiustment
The water pump and generator drive. belt is prof
erly adjusted when the belt ~an be pressed inward
by hand approximately Y2 inch at a point half-way
between the generator and water pump pull,eys.
To adjust the drive belt, loosen the generator
adjusting arm capscrew, move the generator up
or down to obtain the correct tension of the drive
belt, then tighten the adjusting arm capscrew.

FUEL SYSTEM
A. DESCRIPTION OF SYSTEM
The engine fuel system consists of a fuel tank, first
stage fuel filter, fuel transfer pump, second stage
fuel filter, fuel injection pump, fuel nozzles, and
the fuel· lines. There are two fuel pressure systems;
the low, pressure system and the high pressure
system.
The low pressure system consists of the fuel tank,
first stage fuel filter, fuel transfer pump, second
stage fuel filter, fuel leak-off header, and the fuel
return line leading from the fuel sump of the fuel
injection pump to the fuel tank.
The high pressure sy;~tem. consists of the fuel in-
.d!~!ion pump, fuel n~zzles, and aU high pressure
'• fpll'Jines connecting tlie fuel injectfor, pump to the
(uei no:µles. The high pressure fhel lin~s are
s~c:imles!i ste.el tubing and each line is. the same
l~ngth. These. lines being the same length assures
· thil$tQper timing and the proper amount of fuel
·tq~.ach fuel nozzle. These lines are not interchange-
·~i,fo; when ordering lines· for· replacement, specify
,f\•,.:•.i .,. \ . /
'f9r ;~~ic;h cylit!d~r the line is ordered.
. .
Tl,e,f~~Fis draWh from the fuel tank, through the
Ji:r~fstag(?. f~eF;filter, by the fuel transfer pump.
·The fuel tis th~n .forced by the transfer pump,
through the second stage}uel filter and to the fuel
inj~ction pump. The amount of fuel required for
~o,:nbustion. is forced under high pi:essure by the
fuel injection pump, through the high pressure fuel
FUEL PRESSURE RELIEF VALVE
ENGINE
lines to the fuel nozzles, from which the fuel enters
the engine combustion chambers in the form of a
fine cone-shaped spray.
There is a certain amount of fuel seepage between
the lapped surfaces of each fuel nozzle va.lve and
its body, which is necessary for lubrication. This
leakage of fuel accumulates around the spindle ·
and in the spring compartment of each fuel nozzle,
and is returned through the leak-off header to the
fuel return line, extending to the fuel tank. The
excess fuel delivered to the fuel injection pump by
the fuel transfer pump is returned to the fuel tank
through the fuel return line. A pressure of 5 to 15
P.S.I. is maintained within the low pressure fuel
system by a fuel pressure relief valve installed in
the fuel return outlet of the fuel injection pump.
The heavy-duty fuel injection pump is of the con-
stant-stroke, distributing-plunger, sleeve control
type, the plunger being actuated by a cam and
tappet arrangement which also carries the gearing
for the distribution function. Its purpose is to meter
the fuel accurately and deliver it precisely at a
definite moment in the engine cycle and under
high pressure to the fuel nozzles. The fuel injection
pump plunger is 9 M.M. in diameter and the pump
is controlled by .a mechanical-centrifugal type
(type· "C'? governor).
The function of the fuel nozzles is to direct the
metered quantity of fuel, received from the fuel
injection pump, into the engine combustion cham-
TO FUEL PRESSURE GAGE
(SPECIAL EQUIPMENT)
r1 1
SECOND ST AGE FUEL FILTER
FUEL TRANSFER PUMP
FIRST STAGE FUEL FILTER
-
FUEL
TANK
Loo-------------- Fuel Flow -Schematic Diagram --------------'
FIG. 11
.. 22