NACD 1019024AM User manual

NACD Power Take-Off Service Manual
1019024AM
14” HD, 14” HD(DP) and 14” HD(TP) Clutches
Includes Installation, Operation, Maintenance and Overhaul Instructions

North American Clutch & Driveline
Rockford, Illinois
Phone: [phone]
[phone]
Fax [phone]
www.naclutch.com

North American Clutch & Driveline
Rockford, Illinois
Phone: [phone]
[phone]
Fax [phone]
www.naclutch.com
NOTICE
IMPORTANT INFORMATION
It is imperative that proper installation, maintenance, operation and safety procedures be followed explic-
itly regarding products manufactured by North American Clutch & Driveline.
GENERAL:
Safe working and operating practices must be employed by all personnel working on, with, or near NACD
products. NACD will not be responsible for personal injury.
SAFETY NOTICE:
Accidents may result from use of manufactured products, resulting in possible danger to
person(s) or property. Therefore, it is important and imperative that correct, safe procedures
be followed. Products must be installed, maintained, operated and used in accordance with
the engineering information specied. Continual and repeated inspections and observations
should be employed as necessary to assure that safe operations and a safe environment exist
under prevailing conditions. Use proper guards and other suitable safety equipment, devices
and procedures that may be desirable or specied in safety codes, or as necessary to prevent
accidental injury to person(s) or property. These devices are neither provided by NACD nor are
they the responsibility of NACD.
OWNER / OPERATOR / USER RESPONSIBILITIES:
Knowledge of and performance of the procedures specied in this publication are the responsibility of the
owner(s), operator(s), user(s) and all person(s) working on or near the products described herein. Follow-
ing these procedures and explicit adherence to the information described should ensure safe and reliable
use, repair, and operation of products provided by NACD.
WARRANTY:
NACD’s limited Warranty is described in detail in this publication. It is the responsibility of the original pur-
chaser or manufacturer, successive buyers, users, third parties or employees to make themselves aware
of this warranty and all conditions it contains.

North American Clutch & Driveline
Rockford, Illinois
Phone: [phone]
[phone]
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1.0 INTRODUCTION
1.1 Part Numbering System
1.2 Locating The Part Number And Serial Number
2.0 GENERAL INFORMATION, SPECIFICATIONS & RECOMMENDATIONS
2.1 Basic Dimensions for SAE Housings
2.2 Basic Dimensions for SAE Flywheels
2.3 Application Guidelines
2.4 Allowable Side Load Pulls
2.5 Maximum Safe Operating Speeds
2.6 Required Clutch Torque Capacity
2.7 Alignment Tolerances For Flywheels & Flywheel Housings
3.0 MAINTENANCE
3.1 Lubrication Requirements
3.1.1 Grease Specication
3.1.2 Grease Specication For Special Conditions
3.2 Lubrication Intervals
3.3 Bearing Operating Temperature
3.4 Methods of measuring clutch engagement force
3.4.1 Torque Wrench Method (Preferred Method)
3.4.2 Standard handle length
3.4.3 Altered handle length
3.5 Clutch Adjustment Procedure
4.0 INSTALLATION INFORMATION
4.1 Preparation
4.2 Flywheel And Flywheel Housing Alignment Checks
4.3 Lubrication Required Before Installation
4.4 Install the PTO on the engine
4.5 Correct Handle Installation Position
4.6 Check Clutch Engagement Pressure
4.7 Support plate shimming and alignment
4.8 Outboard bearing shimming and alignment
5.0 OPERATION
5.1 Clutch Engagement Procedure
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TABLE OF CONTENTS

North American Clutch & Driveline
Rockford, Illinois
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6.0 EXPLODED VIEWS - TYPICAL POWER TAKE-OFFS
6.1 PTO Exploded Views (exclude clutch)
6.2 Clutch Assembly Exploded View
7.0 DISASSEMBLE THE POWER TAKE-OFF
7.1 Remove accessories attached to the PTO
7.2 Remove the PTO from the engine
7.3 Remove the clutch from the shaft
7.4 Separate the bearing housing from the bell housing
7.5 Remove the shaft and bearings from the bearing housing
7.6 Remove the main bearings from the shaft
7.7 Remove the cross shaft
8.0 INSPECT THE POWER TAKE-OFF COMPONENTS
9.0 DISASSEMBLE THE CLUTCH
9.1 Preparation For Disassembly
9.2 Remove the release sleeve and bearing sub-assembly
9.3 Disassemble the sleeve and bearing sub-assembly
9.4 Remove the adjusting ring sub assembly
9.5 Complete the disassembly of the clutch
10.0 INSPECT THE CLUTCH COMPONENTS
11.0 ASSEMBLE THE CLUTCH
11.1 Assemble the sleeve and bearing sub-assembly
11.2 Assemble the clutch body sub-assembly
11.3 Install the release levers
11.4 Install the release sleeve and bearing assembly
12.0 ASSEMBLE THE POWER TAKE-OFF
12.1 Install the Main Bearings on the Drive Shaft
12.2 Install the drive shaft in the bearing housing
12.3 Join the bearing housing and bell housing
12.4 Install the cross shaft and clutch release yoke
12.5 Complete the assembly of the housing unit
13.0 ADJUST THE MAIN BEARING END PLAY
14.0 INSTALL THE CLUTCH ON THE DRIVE SHAFT
15.0 TROUBLESHOOTING GUIDE
16.0 WARRANTY
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TABLE OF CONTENTS

North American Clutch & Driveline
Rockford, Illinois
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1.0 INTRODUCTION
Performance of the following procedures by the owner and operator should ensure
reliable PTO operation.
1.1 Part Numbering System
NACD Power Take-Off part numbers have changed in the way they were displayed in
print over the years, primarily due to advances in technology.
The part number format for an NACD Power Take-Off is 4XXXXXAM, where XXXXX
is a 5 digit alpha number unique to that particular assembly. Sub-assemblies or kits
are designated 3XXXXXAM and individual components are designated 2XXXXXAM,
where XXXXX is a 5-digit alpha number unique to that particular sub-assembly, kit or
component.
Previous numbers may have been displayed as:
4-XXXXX, 40XXXXX, 04-XXXXX, or 4-OXXXXX. The unique 5-digit number remains
unchanged, regardless of how the prex may have been written at one time or another.
1.2 Locating The Part Number And Serial Number
Refer to the nameplate for part number information. The serial number will be stamped
into the bell housing in the location shown in the bottom picture.
SAE Housing Size
& Clutch Size NACD Part #
Customer Part #
Serial #

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2.0GENERALINFORMATION,SPECIFICATIONS&RECOMMENDATIONS
2.1 Basic Dimensions for SAE Housings
2.2 Basic Dimensions for SAE Flywheels
SAE
Hsg
No.
Clutch
Size
“0”
“1”
14
14-DP
14-TP
14-TP
18.375
18.375
18.375
18.375
17.250
17.250
17.250
17.250
1.00
1.00
1.00
1.00
8
8
8
8
1/2
1/2
1/2
1/2
3.1496 (80mm)
3.1496 (80mm)
3.1496 (80mm)
3.9370 (100mm)
“A”
25.500
20.125
“B”
28.00
21.75
“C”
26.750
20.875
“D”
3.94
3.94
Qty
16
12
Hole Dia
.547
.184
Bolt Size
1/2
7/16
Pilot
Diameter
Drive
Ring
Pilot "F"
Bolt
Circle
"G"
Housing
Face to
Flywheel
"H"
Pilot Bearing
Bore “J”
Bolt Hole "K"
Qty. Size
O.D. Bolt Circle (See Side
Note)
Flywheel Housing Bolts
and Bolt Holes “E”
All dimensions are in inches unless
otherwise specied. “D”= Depth of pilot
bore from housing face to shoulder on
ywheel or to crankshaft ange face.
All dimensions are in Inches unless otherwise specied.

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2.3a Application Guidelines
NACD 14” HD, 14” HD(DP) and 14” HD(TP) Power Take-Offs designed with tapered
roller type main bearings (9)(see illustration in section 6.1) are not approved for in-line
drive applications.
2.3b Application Guidelines
Segmented facings in 2-plate (DP) and 3-plate (TP) Clutches - NACD does not approve
the use of segmented facings in 2-plate (DP) and 3-plate (TP) clutches.
2.4 Allowable Side Load Pulls
The following formula can be used to estimate applied side loads. Loads are calculated
on proper tensioning of belts. If belts are tightened excessively, the resulting side load
can exceed the calculated value. If belts are under tightened, belt “whip” and other
resultant factors can cause intermittent side load pulls which exceed allowable limits.
Note: Side load charts are not furnished for some Power Take Offs because the PTO is
not designed for side-load applications or the pilot bearing is provided by the customer.
Pilot bearing size and type are integral to allowable side load pull calculations. Therefore
allowable side load charts cannot be furnished unless bearing information is known.
Please contact the NACD sales department to obtain an application data sheet for
engineering review.
L =xF x A
126000 x H.P.
N x D
L = Actual Applied Load (lbs.)
HP = Horsepower
N = Shaft Speed (rev./min.)
D = Pitch Diameter of Pulley, etc. (in.)
F = Load Factor (see below)
A = 1.0 for low & moderate duty drives
1.4 for severe duty shock loads or large
inertia loads (reciprocating compressors,
crusher, chippers, planers, etc.)
1.0 for chain
2.5 for V belt drive
3.5 for flat belt drive

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2.5 Maximum Safe Operating Speeds
Maximum safe operating speed is 2200 rpm for NACD Power Take-Offs with 14” HD,
14” HD (DP) or 14” HD (TP) clutches used for either in-line or side load drives.
2.6 Required Clutch Torque Capacity
To determine the actual torque capacity required of a clutch used for any given
application the maximum engine torque and torque service factor must be considered.
See the following chart and formula to calculate the proper clutch capacity required for
the application.
2.7 Alignment Tolerances For Flywheels & Flywheel Housings
NOTE: NACD recommends that engine ywheel housings used with NACD PTO’s be
made of quality cast iron or other material of equal or better strength. Aluminum ywheel
housings have been found to provide insufcient strength to properly maintain bearing
alignment and support the weight and forces related to the application.
Check the alignment of the engine ywheel and the engine ywheel housing. Excessive
bore and face runout of the ywheel, ywheel housing, and ywheel housing adapters,
if used, can adversely affect the performance of the PTO and the system of which it is
part. A dial indicator will be required to measure alignment.
Required Clutch Torque Capacity Calculation:
Required Clutch Torque = Maximum Engine Torque x Service Factor
Blower or Vacuum
Centrifugal with free ow of air
With high start-up inertia or subject
to choking of air supply
Compressors
Reciprocating, 1 or 2 cylinders
Reciprocating, 3 or more cylinders
Roto screw or turbine
Conveyor
Fed uniformly
Not fed uniformly
Recriprocating
Drills
Generator
Pump
Centrifugal or Turbine
Dredge
Mud or reciprocating
Rock Crusher, Hammer Mill
Snow Blower
Wood Chipper, Saw Mill
Ratings: Shafts, bearings and clutch capacities are rated on a conservative
basis. For unusually heavy starting loads, frequent engagment service,
or if prime mover is engine of less than 4 cylinders, consult our sates
representatives for recomendations. Extremely low speed engines require
special consideration.
1.7
4.0
4.0
2.5
2.0
1.5
2.0
3.0
2.0
2.0
1.5
2.0
3.0
3.0
2.0
3.0

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2.7.1 Flywheel Housing Face Runout Deviation Check
Mount the indicator base on the face of the ywheel and position
the dial indicator tip perpendicular to the ywheel housing
mounting ange face. Rotate the ywheel through 360 degrees.
Note: The ywheel and crankshaft of the engine must be held
against either the front or rear of the crankshaft thrust bearing while
the total indicator sweep (TIR) measurement is being made.
The total indicator reading should not exceed:
SAE #0 Housing .010” (.254 mm.)
SAE #1 Housing .008” (.203mm.)
Note: Identify SAE Housings. See 2.1 for
identication of SAE Housings.
2.7.2 Flywheel Housing Bore Runout Deviation Check
Mount the indicator base on the face of the ywheel and position
the dial indicator tip so its movement is perpendicular to the pilot
bore surface of the ywheel housing. Rotate the ywheel through
360 degrees.
The total indicator reading should not exceed:
SAE #0 Housing .10” (.254 mm.)
SAE #1 Housing .008” (.203 mm.)
2.7.3 Flywheel Face Runout Deviation Check
Mount the indicator base on the ywheel housing and position the
dial indicator tip so its movement is perpendicular to the face of
the ywheel. The indicator tip should be positioned near the drive
ring mounting bolt circle diameter. Rotate the ywheel through 360
degrees.
Note: The ywheel and crankshaft of the engine must be held
against either the front or rear of the crankshaft thrust bearing while
the total indicator sweep (TIR) measurement is being made.
Measure the diameter of the drive ring bore in the ywheel.
If bore = 18.375” (466.7 mm.) TIR = .009” (.229 mm.) max.
6

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2.7.4 Flywheel Drive Ring Pilot Bore Runout Deviation Check
Mount the indicator base on the ywheel housing and position the
dial indicator tip so its movement is perpendicular to the drive ring
pilot bore surface of the ywheel. Rotate the ywheel through 360
degrees.
The total indicator reading should not exceed:
SAE #0 Housing: 0.005 inches (0.127 mm.)
SAE #1 Housing: 0.005 inches (0.127 mm.)
2.7.5 Flywheel Pilot Bearing Bore Runout Deviation Check
Mount the indicator base on the ywheel housing and position
the dial indicator tip so its movement is perpendicular to the pilot
bearing bore surface of the ywheel through 360 degrees.
The total indicator reading should not exceed:
SAE #0 Housing: 0.005 inches (0.127 mm.)
SAE #1 Housing: 0.005 inches (0.127 mm.)
3.0 MAINTENANCE
3.1 Lubrication Requirements
3.1.1 Grease Specication
USE ONLY NGLI (National Grease & Lubrication Institute) APPROVED High grade,
lithium base #2, short bre grease with an EP (Extreme Pressure) additive recommended
for use in high speed roller bearings operating at 200° F (93.3° C.).
3.1.2 Grease Specication For Special Conditions
For ambient temperatures above 100° F. (37.8°C.), contact NACD for specications.
Grease caution: Do not mix sodium or calcium based greases with lithium grease. Do
not mix different types of greases under any circumstances in NACD Power Take-Offs.
Do not use molybdenum disulfade grease.
3.2 Lubrication Intervals
The following lubrication intervals are suggested as guidlines. The owner operator
is responsible for establishing lubrication intervals appropriate to the duty cycle and
environmental operating conditions to which the PTO is subjected.

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3.2.1 Bronze & Greasable Ball Type Release Bearing
Using a hand operated grease gun, add 1 or 2 pumps of grease per 8-10 hrs. of
operation (or add grease until grease begins to weep from the I.D. of the bearing and
from between the release sleeve and the shaft). Rotate the shaft (by hand) while adding
grease. DO NOT OVER GREASE!
3.2.2 Main Bearings
Grease every 100 hours
of operation. Add grease
until grease is forced out of
the labyrinth seal(s) around
the shaft. Manually (not by
starting the engine) rotate the
shaft while adding grease.
3.2.3 Pto Cross Shaft
Grease every 500 hours of
operation. Add one or two
pumps of grease from a hand
operated grease gun.
3.2.4 Clutch Linkage And
Levers
Lubricate sparingly with
engine oil every 500 hours of
operation.
3.2.5 Pilot Bearing (Except Non-Greasable Type)
Using a hand operated grease gun, add 1 or 2 shots of grease per 100 hrs. of
operation.
3.2.6 Pilot Bearing (Non-greasable Type)
Cartridge-type pilot bearings are sealed units and require no additional lubrication.
The lubrication intervals and the amount of grease used should be adjusted to minimize
the amount of grease forced out of the bearing housing and the clutch release bearing.
A small amount of grease driven from the bearing housing and the clutch release
bearing is an indication that enough grease is being provided.
Some PTO shafts
have 2 possible grease
locations; one location
will be plugged and the
other will have a grease
tting. If the PTO uses a
non-greasable cartridge
type pilot bearing,
both locations will be
plugged or the shaft will
have no drilled passage-
ways at all.
8
Pilot Bearing
Cross Shaft
Release Bearing
Main Bearing

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3.3 Bearing Operating Temperature
3.3.1 Main Bearing
Operating temperature range is normally between 170°F. and 200°F. (76.7°C. to
93.3°C.). Locations with high ambient temperatures such as desert climates will cause
the bearings to operate at a higher temperature. More frequent lubrication intervals
and/or specialized grease designed for higher operating temperatures will be required.
See following note.
Note: There is a tendency to test temperature with the hand However, it is difcult
to hold a hand on a bearing housing operating at 150°F. (65.6°C.), although that
temperature is below the normal 170°F. (76.7°C.) operating temperature of the PTO.
Therefore a thermometer (contact type) should be used to make reasonably accurate
temperature measurements.
3.4 Methods of measuring clutch engagement force:
The model 14” HD, 14” HD (DP), and 14” HD(TP) clutches described in this manual do
not automatically adjust to compensate for wear of the clutch facing(s), and therefore
must be manually adjusted. Maintaining the correct engagement pressure is the
responsibility of the owner/operator. The owner/operator must periodically adjust the
clutch to ensure correct clutch operation. See section 3.5.
The clutch should be adjusted if the force required to engage the clutch drops by
10-15% of the specied engagement force. Destructive damage may have already
occurred if engagement force is allowed to diminish to the point where the clutch fails
to carry the load (slippage), or if facing(s) have over heated.
Caution: Torque wrench readings are in FOOT-POUNDS, which are different values from
spring scale readings which are in POUNDS OF FORCE. There is no direct correlation
between FOOT-POUNDS and POUNDS OF FORCE. Do not confuse the two different
kinds of values.
Note: New clutches or new facings usually require several, frequent adjustments until
the friction facing surfaces have “worn in”. The clutch friction facing plate(s) will become
glazed, and possibly permanently damaged if the clutch is permitted to slip excessively.
Note: If the facings have been slipped excessively, and enough heat was generated that
the facings began to smoke, the clutch material may have been destroyed. Excessive
heat normally destroys the friction material. Therefore further clutch adjustment will not
remedy slippage problems, replace “burned” facing plates.
9

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3.4.1 Torque Wrench Method (Preferred Method)
A torque wrench should be used at the cross shaft to measure engagement force. The
following chart shows torque readings that represent proper clutch engagement force.
The clutch should ENGAGE within the torque readings shown.
An adapter, NACD Part Number 236484AM may be obtained to provide a 1 1/2” hex
nut at the end of the cross shaft. The adapter may be used in place of the standard
handle for the purpose of checking clutch adjustment with a torque wrench, or it may be
installed on the end of the cross shaft opposite the standard handle. All NACD handles
are cast with this hex. (Most PTO’s have serations on both ends of the cross shaft.)
Note: These values include a 15% allowance for friction
within the clutch release mechanism.
3.4.2 Spring Scale Method Using A Standard Handle
Determine whether the engagement force is correct.
Measure the distance from the bottom of the handle grip
location to the center of the cross shaft. Attach a spring
scale to the handle at the location specied below and
pull the scale perpendicular to the handle to measure the
force required to engage the clutch.
10
Clutch Size
14” HD & HD (DP)
14” HD & HD (TP)
Handle Length
Cross Shaft to Grip
Release Yoke
Length
Engagement Force
80-90 lbs. (356-400N.)
72 lbs.(320 N.)
68 lbs.(302 N.)
4.0" (10.16 cm.)21" (53.3 cm.)
4.5" (11.43 cm.)21" (53.3 cm.)
Original Setting
10% Decrease
15% Decrease
90-120 lbs. (400-534N.)
81 lbs. (360N.)
77 lbs. (342N.)
Original Setting
10% Decrease
15% Decrease
Yoke Length
4.0” Release Yoke
4.5” Release Yoke
Torque @ Cross-Shaft to Engage Clutch
163 to 183 ft. lbs. (221 to 248 Nm.)
183 to 208 ft. lbs. (248 to 282 Nm.)
Length

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3.4.3 Spring scale method with altered or special handle length
For other handle lengths, us the following formula and the values shown in the
following chart.
x = 1.15 x (A x Y)
B
3.5 Clutch Adjustment Procedure
If the clutch requires adjustment, remove the PTO nameplate, disengage the clutch and
rotate it to gain access to the adjustment lock nger.
With a screwdriver, rotate the lock pin (402) to disengage the adjustment lock nger
(401) from the splined teeth of the clutch body.
Note: Do not loosen or remove the machine screw (405). DO NOT REMOVE the lock
spring (407) OR BEND it away from the adjustment lock nger. The lock spring will be
damaged and may not t snugly in the detent slot of the adjustment lock nger
Rotate the adjusting ring clockwise to tighten the clutch. Rotating the adjusting
ring counter-clockwise will loosen the clutch. Adjust to obtain the proper clutch
engagement force by using one of the methods described in section 3.4. (Torque
wrench method in section 3.4.1 is the preferred method.)
11
X Engagement force at attachment point
Y Engagement force at clutch release bearing
A Length of clutch release yoke
B Length of handle (cross shaft to attachment point)
lbs. force
425 lbs.
4.50”, 4.00”
inches
(newtons)
(1890 newtons)
(11.43 cm.), (10.16 cm.)
centimeters
Machine Screw (405)
DO NOT REMOVE
Lock Spring (407)
DO NOT REMOVE OR BEND
Screwdriver Slot
Screwdriver Slot
Adjustment Ring
Adjustment Lock Finger (401)
Lock Pin (402)

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When the clutch is properly adjusted, reposition the adjustment lock nger between the
splined teeth, making sure the lock nger is completely perpendicular to the main shaft,
and the spring steel lock spring is positioned in the “detent slot” of the nger so it is
securely locked.
Repeat the procedure in 3.4.1, 3.4.2, or 3.4.3, to recheck for proper engagement force.
Note: A new clutch installation usually requires several adjustments until the friction
facing surfaces have “worn in”. The clutch friction facing(s) will become glazed, and
possibly permanently damaged, if the clutch is permitted to slip excessively.
4.0 INSTALLATION INFORMATION
4.1 Preparation
Do not disengage the clutch before installing the PTO on the engine. Disengagement
allows the clutch plates to slip out of the correctly aligned positions established at
NACD.
4.1.1 If the facing plates have become misaligned, they may be realigned by using
the drive ring as a gauge. If the plates require alignment, follow the procedure
outlined below.
4.1.2 Support the PTO unit
with the output shaft hanging
straight down. Blocks or a
hoist can be used to hold the
PTO in position.
Lock Spring (407)
Machine Screw (405)
Lockwasher (408)
Detend Slot in Finger
Adjustment Lock Finger (401)
Clutch Body
Facing
Drive Ring
PTO Housing
Center the drive ring relative to
clutch body

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4.1.3 Use the clutch drive ring provided with the PTO or remove the drive ring from the
engine ywheel to use as an alignment gauge. Place the drive ring over the clutch facings
with the clutch disengaged. Mesh the drive teeth of the facings with the drive ring and
align the facings by centering the drive ring relative to the O.D. of the clutch body. While
holding the drive ring and facings centered, engage the clutch.
4.1.4 Remove the drive ring.
4.2 Flywheel And Flywheel Housing Alignment Checks
It is strongly recommended that dial indicator checks be made (as shown in section 2.7)
prior to installation of the PTO, especially on new engines or when bearing failures or
shaft wear were found after the previous PTO was removed and examined for cause of
failure.
4.3 Lubrication Required Before Installation
4.3.1 See section 3.1 for information on the type(s) of lubricant(s) required.
4.3.2 Lubricate as follows before installation: (See illustration in section 3.2 for locations
of grease ttings)
Release Bearing: (except non-greasable type)
Bronze and greasable ball-type release bearing:
With a hand operated grease gun, add 1 or 2 pumps of grease per 8-10 hrs. operation (or
until grease begins to weep from the I.D. of the bearing and the release sleeve.) Rotate
the shaft (by hand) while adding grease. DO NOT OVERGREASE!
Release Bearing: (non-greasable type)
Non-greasable ball bearing type release bearing:
Sealed bearing-no lubrication required.
Main Bearing:
With a hand operated grease gun, add 1 or 2 pumps of grease while rotating the shaft (by
hand), or until grease weeps from the labyrinth seals around the shaft at either end of the
bearing housing.
Pilot Bearing Lube Passage:
Some PTO’s have a hole drilled through the length of the shaft to provide lube to the pilot
bearing. The grease tting may be located either at the end or on the side of the output
13

North American Clutch & Driveline
Rockford, Illinois
Phone: [phone]
[phone]
Fax [phone]
www.naclutch.com
shaft. Add grease until the center passage is lled with grease. Be sure that the
shipping plug is removed from the pilot bearing end of the shaft.
Cross Shaft:
With a hand operated grease gun, add 1 or 2 shots of grease into each of the grease
ttings located in the PTO housing, near each end of the cross shaft.
4.4 Install the PTO on the engine.
4.4.1 Install the drive ring on the engine ywheel. Be sure that the ring is seated in the
locating bore. Use U.S.A. SAE Grade 5 bolts (or equivalent) with lock washers.
Torque the bolts (1/2”-13) to 67 to 80 ft. lbs. (91 to 108 Nm.)
Use the engine manufacturer’s torque specications if different from above.
Some engines use metric bolts. Refer to the engine manufacturer’s torque
specications.
4.4.2 (For greasable pilot bearing ONLY). If a pilot bearing adapter is used on the
ywheel, be sure the mating surface(s) between the adapter and the ywheel face are
sealed to prevent loss of grease from the pilot bearing grease cavity due to vacuum or
centrifugal force. Loctite® 515 or equivalent is suggested.
4.4.3 Proceed as follows:
For greasable pilot bearing ONLY: (bearing has a grease shield on 1 side only) Pack
the ywheel pilot bearing cavity with grease. Install the pilot bearing in the ywheel or
adapter with the grease shield of a greasable bearing toward the PTO and clutch. Be
sure that the pilot bearing spacer, if used, is in place. Two types of spacers may be
used. Spacers may be installed in the ywheel to keep the pilot bearing from going
too far into the bore in the ywheel, and a spacer may be used on the pilot end of the
PTO shaft between the pilot bearing and the PTO to help maintain proper pilot bearing
location in the ywheel bore.
For non-greasable pilot bearing ONLY: (bearing has 2 grease seals) Non-greasable,
double-sealed pilot bearings require no relubrication and may be installed in the
ywheel or adapter with either side toward the PTO clutch. The shaft should have no
grease ttings. If it does, remove the grease tting(s) and replace with pipe plugs as a
precaution to insure grease is not forced into the pilot bearing cavity of the ywheel.
A build-up of pressure caused by forcing grease into the cavity can cause the pilot
bearing to be forced out of the ywheel, resulting in a bearing or shaft failure.
14

North American Clutch & Driveline
Rockford, Illinois
Phone: [phone]
[phone]
Fax [phone]
www.naclutch.com
4.4.4 Install the PTO with the cross shaft in a horizontal position. Install two (2) 5” long
guide bolts into the ywheel housing bolt holes, located approximately at the 3 o’ clock
and 9 o’ clock positions. Position the PTO on the guide bolts to help align the unit and
support the weight while the mounting bolts are installed.
Start the PTO shaft in the pilot bearing. Carefully align the clutch facing teeth with the
teeth in the drive ring. Temporarily install longer bolts in 4 bolt holes 90° apart, and
tighten the bolts alternately and evenly to draw the PTO housing toward the ywheel
housing. Replace the longer bolts with the shorter ones as necessary, and tighten
to draw the PTO into place. Then remove the temporary bolts and guide bolts, and
replace them with proper mounting bolts. Install bolts and lockwashers. Use U.S.A.
SAE Grade 5 bolts (or equivalent) with lockwashers. Torque bolts according to the
following chart.
Note: Many engines use metric threads, so the following chart would not be applicable.
Do not use bolts made with U.S. threads in holes with metric threads. The threads will
be damaged, rendering them unusable.
Use the engine manufacturer’s torque specications if different from the above torque
recommendation.
4.4.5 Rap the output end of the shaft with a soft mallet to relieve any pre-load on the engine
crankshaft that may have built up as a result of the pilot bearing’s t on the shaft pilot
4.5 Correct Handle Installation Position:
Install the clutch handle or release mechanism. Position the handle
so that it is pointing either straight up or straight down when the
clutch is in the engaged position. Positioning the lever vertically
minimizes loading on the release bearing.
If an altered or special clutch engagement mechanism is used
(remote linkage mechanism is not recommended), be sure there
is no pre-load on the release bearing either sideways or toward
the engaged or release position. There should be no pre-load on
the cross shaft in any direction, forward, rearward or sideways. A
torsional and forward or rearward load (only) will be applied (only)
during the engagement or disengagement cycle.
15
SAE #1 Hsg. (7/16-14 bolts) 42-50 ft. lbs. (57-68 Nm.)