
A "howling" or "whining" noise from the ring and pinion gear can be caused by an improper gear pattern, gear damage, or improper bearing
preload. It can occur at various speeds and driving conditions, or it can be continuous.
Before disassembling axle to diagnose and correct gear ke sure that tires, exhaust, and vehicle trim have been checked as possible causes.
Chuckle
This is a particular rattling noise that sounds like a stick against the spokes of a spinning bicycle wheel. It occurs while decelerating from 40
MPH and usually can be heard until vehicle comes to a complete stop. The frequency varies with the speed of the vehicle.
A chuckle that occurs on the driving phase is usually caused ive clearance due to differential gear wear, or by a damaged tooth on the coast
side of the pinion or ring gear. Even a very small tooth nick or a ridge on the edge of a gear tooth is enough the cause the noise.
This condition can be corrected simply by cleaning the gear tooth nick or ridge with a small grinding wheel. If either gear is damaged or scored
badly, the gear set must be replaced. If metal has broken loose, the carrier and housing must be cleaned to remove particles that could cause
damage.
Knock
This is very similar to a chuckle, though it may be louder, and occur on acceleration or deceleration. Knock can be caused by a gear tooth that
is damaged on the drive side of the ring and pinion gears. Ring gear bolts that are hitting the carrier casting can cause knock. Knock can also be
due to excessive end play in the axle shafts.
Clunk
Clunk is a metallic noise heard when an automatic transmission is engaged in Reverse or Drive, or when throttle is applied or released. It is
caused by backlash somewhere in the driveline, but not necessarily in the axle. To determine whether driveline clunk is caused by the axle,
check the total axle backlash as follows:
1. Raise vehicle on a frame or twinpost hoist so that drive wheels are free. Clamp a bar between axle companion flange and a part of the
frame or body so that flange cannot move.
2. On conventional drive axles, lock the left wheel to keep it from turning. On all models, turn the right wheel slowly until it is felt to be in
Drive condition. Hold a chalk marker on side of tire about 12" from center of wheel. Turn wheel in the opposite direction until it is
again felt to be in Drive condition.
3. Measure the length of the chalk mark, which is the total axle backlash. If backlash is one inch or less, drive axle is not the source of
clunk noise.
Bearing Whine
Bearing whine is a high-pitched sound similar to a whistle. It is usually caused by malfunctioning pinion bearings. Pinion bearings operate at
drive shaft speed. Roller wheel bearings may whine in a similar manner if they run completely dry of lubricant. Bearing noise will occur at all
driving speeds. This distinguishes it from gear whine, which usually comes and goes as speed changes.
Bearing Rumble
Bearing rumble sounds like marbles being tumbled. It is usually caused by a malfunctioning wheel bearing. The lower pitch is because the
wheel bearing turns at only about 1/3 of drive shaft speed.
Chatter On Turns
This is a condition where the entire front or rear of vehicle vibrates when vehicle is moving. The vibration is plainly felt as well as heard. Extra
differential thrust washers installed during axle repair can cause a condition of partial lock-up that creates this chatter.
Axle Shaft Noise
Axle shaft noise is similar to gear noise and pinion bearing whine. Axle shaft bearing noise will normally distinguish itself from gear noise by
occurring in all driving modes (Drive, cruise, coast and float), and will persist with transmission in Neutral while vehicle is moving at problem
speed.
If vehicle displays this noise condition, remove suspect parts, replace wheel seals and install a new set of bearings. Re-evaluate vehicle for
noise before removing any internal components.
Vibration
Vibration is a high-frequency trembling, shaking or grinding condition (felt or heard) that may be constant or variable in level and can occur
during the total operating speed range of the vehicle.
The types of vibrations that can be felt in the vehicle can d into 3 main groups:
Vibrations of various unbalanced rotating parts of the vehicle.
Resonance vibrations of the body and frame structures caused by rotating of unbalanced parts.
Tip-in moans of resonance vibrations from stressed engine or exhaust system mounts or driveline flexing modes.
DRIVE AXLE - RWD TROUBLE SHOOTING
NOTE:This is GENERAL inform ation. This article is not intended to be specific to any unique situation or
individual vehicle configuration. T he purpose of this T rouble Shooting inform ation is to provide a list
of com m on causes to problem sym ptom s. For m odel-specific T rouble Shooting, refer to SUBJECT ,
DIAGNOST IC, or T EST ING articles available in the section(s) you are accessing. For definitions of listed
noises or sounds, see DRIVE AXLE
- NOISE DIAGNOSIS under POWERTRAIN.
Page 28 of 36 MITCHELL 1 ARTICLE - GENERAL INFORMATION Trouble Shooting - Basic Procedures
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SUSPENSION TROUBLE SHOOTING
BASIC SUSPENSION TROUBLE SHOOTING CHART
article
Shroud or housing looseTighten holding screws
Lock plate retaining ring not seatedSee STEERING COLUMN
article
Loose sight shieldTighten holding screws
High Steering Shaft Effort
Co l u mn assemb l y misal ign edSee STEERING COLUMN
article
Improperly installed dust shieldAdjust or replace
Tight steering universal jointSee STEERING COLUMN
article
High Shift Effort
Column is out of alignmentSee STEERING COLUMN
article
Improperly installed dust shieldAdjust or replace
Seals or bearings not lubricatedSee STEERING COLUMNS
article
Mounting bracket screws too longReplace with new shorter
screws
Burrs on shift tubeRemove burrs or replace tube
Lower bowl bearing assembled wrongSee STEERING COLUMN
article
Shift tube bent or brokenReplace as necessary
Improper adjustment of shift leversSee STEERING COLUMN
article
Improper Trans. Shifting
Sheared shift tube jointReplace as necessary
Sheared lower shaft leverReplace as necessary
Improper shift lever adjustmentSee STEERING COLUMN
article
Improper gate plate adjustmentSee STEERING COLUMN
article
Excess Play in Column
Instrument panel bracket bolts looseTighten bolts and check
bracket
Broken weld nut on jacketSee STEERING COLUMN
article
Instrument bracket capsule shearedSee STEERING COLUMN
article
Column bracket/jacket bolts looseTighten bolts and check
bracket
Steering Locks in Gear
Release lever mechanismSee STEERING COLUMN
article
NOTE:This is GENERAL inform ation. This article is not intended to be specific to any unique situation or
individual vehicle configuration. T he purpose of this T rouble Shooting inform ation is to provide a list
of com m on causes to problem sym ptom s. For m odel-specific T rouble Shooting, refer to SUBJECT ,
DIAGNOST IC, or T EST ING articles available in the section(s) you are accessing.
CONDITION & POSSIBLE CAUSECORRECTION
Front End Noise
Loose or worn wheelSee Wheel Bearing
Adjustment in SUSPENSION
Worn shocks or shock mountingsReplace struts or strut
mo u n t in gs
Worn struts or strut mountingsReplace struts or strut
mo u n t in gs
Loose or worn lower control armSee SUSPENSION
Loose steering gear-to-frame boltsSee STEERING
Worn control arm bushingsSee SUSPENSION
Ball joints not lubricatedLubricate ball joints & see
Ball Joint Checking in
SUSPENSION
Front Wheel Shake, Shimmy, or Vibration
Tires or wheels out of balanceCheck tire balance
Incorrect wheel alignmentSee WHEEL ALIGNMENT
Drive shaft unbalancedCheck drive shaft balance
Loose or worn wheel bearingsSee WHEEL ALIGNMENT
Loose or worn tie rod endsSee SUSPENSION
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CLUNK
Clunk is a metallic noise heard when an automatic transmission is engaged in Reverse or Drive, or when throttle is applied or released. It is
caused by backlash somewhere in the driveline, but not necessarily in the axle. To determine whether driveline clunk is caused by the axle,
check the total axle backlash as follows:
1. Raise vehicle on a frame or twinpost hoist so that drive wheels are free. Clamp a bar between axle companion flange and a part of the
frame or body so that flange cannot move.
2. On conventional drive axles, lock the left wheel to keep it from turning. On all models, turn the right wheel slowly until it is felt to be in
drive condition. Hold a chalk marker on side of tire about 12" from center of wheel. Turn wheel in the opposite direction until it is again
felt to be in drive condition.
3. Measure the length of the chalk mark, which is the total axle backlash. If backlash is one inch or less, clunk will not be eliminated by
overhauling drive axle.
BEARING WHINE
Bearing whine is a high-pitched sound similar to a whistle. It is usually caused by malfunctioning pinion bearings. Pinion bearings operate at
driveshaft speed. Roller wheel bearings may whine in a similar manner if they run completely dry of lubricant. Bearing noise will occur at all
driving speeds. This distinguishes it from gear whine, which usually comes and goes as speed changes.
BEARING RUMBLE
Bearing rumble sounds like marbles being tumbled. It is usually caused by a malfunctioning wheel bearing. The lower pitch is because the
wheel bearing turns at only about 1/3 of driveshaft speed.
CHATTER ON TURNS
This is a condition where the whole front or rear vibrates when vehicle is moving. The vibration is easily felt and heard. Extra differential
thrust washers installed during axle repair can cause a condition of partial lock-up that creates the chatter.
AXLE SHAFT NOISE
Axle shaft noise is similar to gear noise and pinion bearing whine. Axle shaft bearing noise will normally distinguish itself from gear noise by
occurring in all driving modes. Noise will persist with transmission in neutral while vehicle is moving at problem speed.
If vehicle displays this noise condition, remove suspect axle shafts and replace axle bearings. Re-evaluate vehicle for noise before removing
any internal components.
VIB R AT ION
Vibration is a high-frequency trembling, shaking or grinding condition (felt or heard) that may be constant or variable in level and con occur
during the total operating speed range of the vehicle.
The types of vibrations that can be felt in the vehicle can be divided into 3 main groups:
Vibrations of various unbalanced rotating parts of the vehicle.
Resonance vibrations of the body and frame structures caused by rotating of unbalance parts.
Tip-in moans of resonance vibrations from stressed engine or exhaust system mounts or driveline flexing modes. NOTE:This is GENERAL inform ation. This article is not intended to be specific to any unique situation or
individual vehicle configuration. For m odel-specific inform ation see appropriate articles where
available.
NOTE:This is GENERAL inform ation. This article is not intended to be specific to any unique situation or
individual vehicle configuration. For m odel-specific inform ation see appropriate articles where
available.
NOTE:This is GENERAL inform ation. This article is not intended to be specific to any unique situation or
individual vehicle configuration. For m odel-specific inform ation see appropriate articles where
available.
NOTE:This is GENERAL inform ation. This article is not intended to be specific to any unique situation or
individual vehicle configuration. For m odel-specific inform ation see appropriate articles where
available.
NOTE:This is GENERAL inform ation. This article is not intended to be specific to any unique situation or
individual vehicle configuration. For m odel-specific inform ation see appropriate articles where
available.
NOTE:This is GENERAL inform ation. This article is not intended to be specific to any unique situation or
individual vehicle configuration. For m odel-specific inform ation see appropriate articles where
available.
Copyr ight 2009 Mitchell Repair Information Company, LLC. All Rights Reserved.
Article GUID: A00002193
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2. Turn test switch knob to ON position (current through switch). Road test vehicle with vehicle accessories on (radio, air conditioner, etc).
After road test, turn ignition switch to LOCKED position and remove key. Connect ammeter terminals to test switch terminals. See Fig.
1. Select 10-amp scale.
3. Turn off all electrical accessories. Turn off interior lights, underhood lamp, trunk light, illuminated entry, etc. To avoid damaging
ammeter or obtaining a false meter reading, all accessories must be off before turning test switch knob to OFF position.
4. Turn test switch knob to OFF position to allow current to flow through ammeter. If meter reads wrong polarity, turn test switch to ON
position and reverse leads. Turn test switch to OFF position. Observe current reading. If reading is less than 2 amps, turn test switch to
ON position to keep electrical circuits powered-up.
5. Select low amp scale. Switch lead to the correct meter position. Turn test switch to OFF position and compare results to normal current
draw. See GENERAL MOTORS PARASITIC LOAD TABLE (MILLIAMPS)
. If current draw is unusually high for the vehicle's
overall electrical system, remove system fuses one at a time until current draw returns to normal.
6. Turn test switch to ON position each time door is opened or fuse is removed. Turn switch to OFF position to read current draw va l u e
through meter. When the cause of excessive current drain has been located and repaired, remove test switch and reconnect negative
battery cable to the negative battery terminal.
INTERMITTENT PARASITIC LOAD PROBLEMS
Intermittent parasitic load can occur because of a memory device that does not power down with ignition off. With an intermittent parasitic
load, battery draw can be greater than 1.0 amp.
To find an intermittent problem requires that an ammeter and Disconnect Tool (J-38758) test switch be connected and left in the circuit. See
Fig. 1
. Road test vehicle. After road test, turn ignition off and remove key.
Monitor the milliamps scale for 15-20 minutes after ignition is turned off. This allows monitoring memory devices to determine if they time out
and stop drawing memory current. The test switch is needed to protect ammeter when the vehicle is started.
Fig. 1: Connecting Kent
-Moore Disconnect Tool (J-38758)
Courtesy of GENERAL MOTORS CORP.
GENERAL MOTORS PARASITIC LOAD
ComponentNormal DrawMaximum DrawTime-Out (Minutes)
Anti-Theft System0.41.0.....
Auto Door Lock1.01.0.....
Body Control Module3.612.420
Central Processing System1.62.720
Electronic Control Module5.610.0.....
Electronic Level Control2.03.320
Heated Windshield Module0.30.4.....
HVAC Power Module1.01.0.....
Illuminated Entry1.01.01
Light Control Module0.51.0.....
Oil Level Module0.10.1.....
Page 2 of 4 MITCHELL 1 ARTICLE - GENERAL INFORMATION Parasitic Load Explanation & Test Procedures
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Back To Article
GENERAL INFORMATION
Manual Transmission Trouble Shooting
* PLEASE READ THIS FIRST *
INTRODUCTION
There are many times when the transmission is incorrectly blamed for shifting problems or noises that are actually caused by other reasons.
Shift difficulties are frequently caused by conditions outside of the transmission or transaxle. Typical conditions include: shift linkage, shift
cables, alignment of engine to transmission, worn engine mounts or clutch problems. Drive train noises may come from many sources such as
tires, road surfaces, wheel bearings, differentials, engine or exhaust system. Repairing or overhauling transmission will not cure these
problems.
No manufacturer makes a perfectly quiet transmission. Gear rollover noise is present in most constant mesh transmissions and will tend to
disappear when the clutch is disengaged or transmission is placed in gear. If clutch is properly adjusted, clutch release bearing noise will
disappear when release bearing is moved enough to slide release bearing away from pressure plate.
Trouble shooting can be helped by driving vehicle on a smooth level road to help eliminate tire and body noise. Note whether noise occurs on
acceleration, coasting, deceleration or steady driving conditions. Some problems may only occur when transmission is either hot or cold. Gear
lubricant that is too thick can cause hard shifting on cold mornings before engine is warm and vehicle has been driven.
MANUAL TRANSMISSION/TRANSAXLE TROUBLE SHOOTING NOTE:This is GENERAL inform ation. This article is not intended to be specific to any unique situation or
individual vehicle configuration. For m odel-specific inform ation see appropriate articles where
available.
NOTE:This is GENERAL inform ation. This article is not intended to be specific to any unique situation or
individual vehicle configuration. For m odel-specific inform ation see appropriate articles where
available.
ConditionPossible Cause
Noisy In Forward GearsLow Gear Oil Level, Loose Bellhousing Bolts, Worn Bearings Or
Gears
Clunk On Deceleration (FWD Only)Loose Engine Mounts, Worn Inboard CV Joints, Worn Differential
Pinion Shaft, Oversized Side Gear Hub Counterbore in Case
Gear Clash When Shifting Forward GearsClutch Out Of Alignment, Shift Linkage Damaged Or Out Of
Adjustment, Gears Or Synchronizers Damaged, Low Gear Oil
Level
Transmission Noisy When Moving (RWD Only); Quiet In Neutral
With Clutch EngagedWorn Rear Output Shaft Bearing
Gear RattleWorn Bearings, Worn Gear Oil, Low Gear Oil, Worn Gears
Steady Ticking At Idle (Increases With RPM)Broken Tooth On A Gear
Gear Clash When Shifting Forward GearsWorn Or Broken Synchronizers, Faulty Clutch
Loud Whine In ReverseNormal Condition (1)
Noise When Stepping On ClutchFaulty Release Bearing, Worn Pilot Bearing
Ticking Or Screeching As Clutch Is EngagedFaulty Release Bearing, Uneven Pressure Plate Fingers
Click Or Snap When Clutch Is EngagedWorn Clutch Fork, Worn Pivot Ball, Worn Or Broken Front
Bearing Retainer
Transmission Shifts HardClutch Not Releasing, Incorrect Gear Oil, Shift Mechanism
Binding, Clutch Installed Backward
Will Not Shift Into One Gear, Shifts Into All OthersBent Shift Fork, Worn Detent Balls
Locked Into Gear, Cannot ShiftClutch Adjustment, Worn Detent Balls
Transmission Jumps Out Of GearPilot Bearing Worn, Bent Shift Fork, Worn Gear Teeth Or Face,
Excessive Gear Train End Play, Worn Synchronizers, Missing
Detent Ball Spring, Shift Mechanism Worn Or Out Of Adjustment,
Engine Or Transmission Mount Bolts Loose, Transmission Not
Aligned
Shift Lever RattleWorn Detents Or Shift Lever, Worn Shift Fork, Worn
Synchronizer Sleeves
Shift Lever Hops Under AccelerationWorn Engine Or Transmission Mounts
(1)Most units use spur cut gears in Reverse and are naturally noisy.
Copyr ight 2009 Mitchell Repair Information Company, LLC. All Rights Reserved.
Article GUID: A00010942
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1991 GENERAL SERVICING
A/C Com pressor Refrigerant Oil Checking
ISOLATING COMPRESSOR
1. Connect service gauge set to the compressor service valves and open compressor valves slightly (turn in clockwise). Start engine and
operate air conditioning. Slowly turn compressor suction valve clockwise toward closed (front-seated) position.
2. When suction pressure is reduced to zero or less, turn off engine and compressor and quickly turn suction valve stem in to full front-
seated position. Suction pressure should be slightly above zero. Turn discharge valve into front-seated position.
3. To check oil level, slowly open compressor crankcase plug to relieve any remaining pressure. After oil level is corrected, cap service
gauge ports on both valves. Back-seat suction service valve to allow refrigerant to enter compressor. Open discharge valve halfway.
4. Loosen discharge service valve cap, allowing refrigerant pressure to force air out of compressor. Back-seat service valve and tighten cap.
Compressor is now ready for operation.
REFRIGERANT OIL
Only new, pure, moisture-free refrigerant oil should be used in the air conditioning system. This oil is highly refined and dehydrated to a point
where moisture content is less than 10 parts per million. The oil container must be tightly closed at all times when not in use, or moisture will
be absorbed into the refrigerant oil from the air.
SERVICING PRECAUTIONS
DISCHARGING SYSTEM PRECAUTIONS
If compressor has stem-type service valves, it can be isolated and removed without discharging entire system. See ISOLATING
COMPRESSOR at the beginning of this article. Otherwise, discharge system completely before loosening any fittings.
DISCONNECTING LINES & FITTINGS TEST
After system is discharged, carefully clean area around all fittings to be opened. Always use 2 wrenches when tightening or loosening fittings
to avoid twisting or distorting lines. Cap or plug all openings as soon as lines are removed. DO NOT remove caps until immediately before
connections are made. This will keep entry of air and moisture to a minimum.
CONNECTING LINES AND FITTINGS
A new gasket or "O" ring should be used in all instances when connecting lines or fittings. Dip "O" ring in new refrigerant oil and ensure it is
not twisted during installation. Always use 2 wrenches to prevent damage to lines and fittings.
PLACING SYSTEM IN OPERATION
After component service or replacement has been completed and all connections have been made, evacuate system thoroughly with a vacuum
pump. Charge system with proper amount of refrigerant and perform a leak test. See REFRIGERANT OIL & R-12 SPECIFICATIONS chart in
this section for system capacities. Be sure to check all fittings that have been opened. After system has been leak tested, make a system
performance check.
ATSUGI ROTARY VANE DRAIN & REFILL
1. Before checking and adjusting oil level, operate compressor at engine idling speed, with controls set for maximum cooling and high
blower speed, for 20 to 30 minutes to return oil to compressor.
2. Stop engine, discharge refrigerant and remove compressor from vehicle. See SERVICING PRECAUTIONS at beginning of article. Drain
compressor oil from compressor discharge port and measure the amount. Oil is sometimes hard to drain when compressor is cool.
Remove oil while compressor is warm.
3. If the amount drained is less than 3 ounces, conduct leak tests at system connections, and if necessary, repair or replace faulty parts.
Check purity of oil and adjust oil level as follows.
4. If amount drained was above 3 ounces, oil level is right. Pour in same amount as was drained. If amount drained was below 3 ounces,
pour in 3 ounces of new refrigerant oil.
BOSCH 6-CYL DRAIN & REFILL
1. Before checking and adjusting oil level, operate compressor at engine idling speed, with controls set for maximum cooling and high
blower speed, for 20 to 30 minutes to return oil to compressor.
2. Stop engine and discharge refrigerant. Remove refrigerant oil level inspection plug on side of compressor. Oil should be at lower lip of
threaded hole. Add necessary new refrigerant oil (if low). Replace inspection plug and tighten to 10-12 ft. lbs. (14-16 N.m). NOTE:Only com pressors with stem -type service valves can be isolated.
NOTE:Recent findings by the EPA indicate that refrigerant is harm ful to the earth's protective Ozone layer.
When discharging refrigerant, DO NOT allow refrigerant to enter the atm osphere. If available, use
refrigerant recovery/recycle system s when discharging system . Always follow m anufacturer's
instructions.
NOTE:Air conditioning system s will not norm ally need addition of refrigerant oil unless definite oil loss has
occurred due to ruptured lines, leaking com pressor seals, com pressor overhaul or com ponent
replacem ent.
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1. Discharge system using approved refrigerant recovery/recycling equipment and remove compressor. Using Spanner (T70P-4067-A),
remove clutch plate retaining bolt and discard. Using an 8-mm bolt threaded into clutch plate, remove clutch plate and shims. See Fig.
2 .
2. Remove shaft felt seal. Thoroughly clean seal area of compressor. Using snap ring pliers, remove shaft seal retaining snap ring.
3. Position Shaft Seal Remover (T89P-19623-BH) over compressor shaft. Push shaft seal remover downward against seal. Ensure end of
shaft seal remover is engaged with inside of seal.
4. Rotate shaft seal remover handle clockwise to expand remover tip inside seal. Pull shaft seal from compressor.
Installation
1. Shaft seal protector is included with replacement seal kit. Lubricate shaft seal protector and shaft seal with refrigerant oil.
2. Install shaft seal on shaft seal protector so lip of seal is toward compressor (large end of shaft seal protector). Install shaft seal protector
on compressor shaft.
3. Using Shaft Seal Installer (T89P-19623-AH), push shaft seal down shaft seal protector until seated. Remove shaft seal installer and
protector. Install NEW shaft seal retaining snap ring.
4. Install NEW shaft seal felt. Install clutch plate. Install new clutch plate retaining bolt and tighten to 96-120 INCH lbs. (11-14 N.m).
5. Using feeler gauge, check clearance between clutch plate and pulley assembly mating surfaces in 3 places. Clearance should be .018-
.033" (.46-.84 mm). If clearance is not correct, add or remove shims.
6. Install compressor. Evacuate and recharge system. Perform leak test.
NIPPONDENSO 6E-171 & 6P-148 CLUTCH ASSEMBLY
Removal
1. Using Spanner (T81P-19623-MH), hold clutch plate and remove crankshaft nut. Using Clutch Plate Remover (T80L-19703-B), pull
clutch plate from compressor. Remove clutch plate shims.
2. Remove snap ring and clutch pulley assembly. If pulley assembly cannot be removed by hand, use Shaft Protector (T80L-19703-G) and
3-jaw puller to remove pulley. Remove snap ring. Disconnect electrical wiring and remove clutch coil.
Installation
1. Install clutch coil over locating pin and install snap ring. Connect electrical wiring.
2. Using Pulley Installer (T80L-19703-J) and hammer (if necessary), install pulley assembly. Install snap ring with beveled side away from
compressor.
3. Install clutch plate shims. Ensure clutch plate aligns with crankshaft key. Using Clutch Plate Installer (T80L-19703-F), install clutch
plate.
4. Install crankshaft nut. Using spanner, tighten nut to 10-14 ft. lbs. (13-20 N.m). DO NOT tighten nut with air tools. Using feeler gauge,
check clearance between clutch plate and pulley.
5. Rotate compressor clutch and check clearance in more than one place. Proper clearance is .021-.035" (.53-.89 mm). If clearance is not
correct, add or remove shims.
NIPPONDENSO 6E-171 & 6P-148 SHAFT SEAL
Removal
1. Discharge system using approved refrigerant recovery/recycling equipment and remove compressor. Drain oil from suction port on
compressor and record amount for reassembly.
2. Remove clutch assembly. See NIPPONDENSO 6E-171 & 6P-148 CLUTCH ASSEMBLY R & I in this article. Ensure outer surface of
compressor is clean. Attach compressor on Clamp & Holding Fixture (T81P-19623-LH). Place fixture in vise.
3. Using Key Remover (T81P-19623-NH), remove key from compressor shaft. Remove front head-to-compressor retaining bolts and front
head. Front valve plate assembly, inlet reed valve and shaft seal assembly come off with front head. See Fig. 1
.
4. Remove dowel pins from front head. Lift inlet reed valve assembly from front head. Using Valve Plate Remover (T81P-19623-PH),
remove front valve plate assembly from front head. Remove shaft seal assembly and felt seal from front head.
5. Place front head on cardboard. Drive shaft seal seat from front head using hammer and Shaft Seal Seat Remover (T81P-19623-OH).
Clean components with solvent.
Installation
1. Place dowel pins in compressor. Lubricate inlet reed valve with refrigerant oil. Install inlet reed valve on compressor. Install front valve
plate assembly on compressor.
2. Lubricate shaft seal seat with refrigerant oil. Install Seat Installer (T81P-19623-C) on new seat so installer is placed on grooved side of
seat. Install shaft seal seat.
3. Install shaft seal assembly in front head so sealing surface is toward end of compressor shaft. Ensure flat areas on shaft seal assembly
engage with flat areas on compressor shaft.
4. Lubricate front head "O" ring with refrigerant oil. Install front head and "O" ring. Tighten retaining bolts in a crisscross pattern to 19 ft.
lbs. (26 N.m). DO NOT use air tools to tighten retaining bolts.
5. Install clutch assembly. Add same amount new refrigerant oil to compressor as was drained. Rotate compressor 10 revolutions to
distribute oil. Install compressor. Evacuate and recharge system. Perform leak test. NOTE:Rem ove com pressor when clearance is not adequate for clutch assem bly rem oval.
CAUT ION: DO NOT dry front valve plate assem bly or inlet reed valve with com pressed air.
CAUT ION: DO NOT touch sealing surfaces of shaft seal assem bly or shaft seat assem bly.
Page 3 of 7 MITCHELL 1 ARTICLE - GENERAL SERVICING 1991 Ford Compressor Overhaul
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NIPPONDENSO 10P13 CLUTCH ASSEMBLY
Removal
1. Discharge system using approved refrigerant recovery/recycling equipment and remove compressor. Using Clutch Holder (1014), hold
clutch plate and remove crankshaft nut. Using Clutch Plate Remover (T80L-19703-B), pull clutch plate from compressor. Remove
clutch plate shims.
2. Remove snap ring and pulley assembly. If pulley assembly cannot be removed by hand, use Shaft Protector (T80L-19703-G) and 3-jaw
puller to remove pulley. Remove snap ring. Disconnect electrical wiring and remove clutch coil.
Installation
1. Install clutch coil over locating pin. Install snap ring with beveled side away from compressor.
2. Install pulley assembly using Pulley Installer (T80L-19703-J) and hammer (if necessary). Install snap ring with beveled side away from
compressor.
3. Install clutch plate shims. Ensure clutch plate aligns with crankshaft key. Install clutch plate using Clutch Plate Installer (T80L-19703-
F).
4. Install crankshaft nut. Using spanner, tighten nut to 10-14 ft. lbs. (13-20 N.m). DO NOT tighten nut with air tools. Using feeler gauge,
check clearance between clutch plate and pulley.
5. Rotate compressor clutch and check clearance in more than one place. Proper clearance is .021-.036" (.53-.91 mm). If clearance is not
correct, add or remove shims.
6. Add same amount new refrigerant oil to compressor as was drained. Rotate compressor 10 revolutions to distribute oil. Install
compressor. Evacuate and recharge system. Perform leak test.
NIPPONDENSO 10P13 SHAFT SEAL
Removal
1. Discharge system using approved refrigerant recovery/recycling equipment and remove compressor. Drain oil from compressor and
record amount for reassembly. Using Clutch Holder (1014), hold clutch plate and remove crankshaft nut.
2. Pull clutch plate from compressor using Clutch Plate Remover (T80L-19703-B). Remove clutch plate shims. Clean compressor area
around seal. Remove felt packing and dust seal retainer from nose of front cover. See Fig. 3
.
3. Using Key Remover (T81P-19623-NH), remove key from compressor shaft. Remove seal seat retaining snap ring. Remove seal seat from
compressor using Seal Seat Remover/Installer (T87P-19623-B).
4. Place Seal Remover/Installer (T87P-19623-C) on compressor. Rotate seal remover/installer clockwise until tangs engage in seal. Pull
seal from compressor.
Installation
1. Lubricate shaft seal, seal seat and inside of compressor nose with refrigerant oil. Install Seal Protector (T71P-19703-H) over compressor
shaft. Using seal remover/installer, install shaft seal in compressor.
2. Rotate seal on compressor shaft to align flat areas on seal with those on compressor shaft.
3. Using seal seat remover/installer, install seal seat until it contacts seal. Install snap ring. Install key in crankshaft with rounded edge
inward.
4. Install clutch plate shims. Ensure clutch plate is aligned with crankshaft key. Using Clutch Plate Installer (T80L-19703-F), install clutch
plate.
5. Install crankshaft nut. Using spanner, tighten nut to 10-14 ft. lbs. (13-20 N.m). DO NOT tighten nut with air tools. Using feeler gauge,
check clearance between clutch plate and pulley.
6. Rotate compressor clutch and check clearance in more than one place. Proper clearance is .021-.036" (.53-.91 mm). If clearance is not
correct, add or remove shims.
7. Add same amount new refrigerant oil to compressor as was drained. Rotate compressor 10 revolutions to distribute oil in compressor.
Install compressor. Evacuate and recharge system. Perform leak test. NOTE:After installing new clutch, cycle clutch 10 tim es with engine at idle speed to prevent clutch slippage.
Page 4 of 7 MITCHELL 1 ARTICLE - GENERAL SERVICING 1991 Ford Compressor Overhaul
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