checking rear diferential preload
checking rear diferential preload Here is theinfo from the shop manual. They dont state if this measurement is with the wheels on or off. I am betting it is measured with the wheels off. Anyone know the correct procedure? I have to replace the leaking seal and I have heard that you just measure the value, replace the seal and tighten the nut until you reach the measured value. Just curious.
xTooltipElement
Service Information
2002 Pontiac Firebird [2g2fv32g722100402] | Camaro, Firebird (VIN F) Service Manual | Driveline/Axle | Rear Drive Axle | Specifications | Document ID: 718716
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Pinion Bearing and Differential Bearing Preload
Application
Specification
Metric
English
Differential Assembly Backlash
Drive Pinion and Ring Gear Backlash
0.13-0.23 mm
0.005-0.009 in
Drive Pinion Bearing Preload
Rotating Torque with New Bearings and New Oil Seal
1.7-3.4 N·m
15-30 lb in
Rotating Torque with Used Bearings and New Oil Seal
1.0-1.7 N·m
10-15 lb in
Total Preload with Carrier Installed
Rotating Torque with New Bearings and New Oil Seal
3.6-6.2 N·m
32-55 lb in
Rotating Torque with Used Bearings and New Oil Seal
1.8-3.1 N·m
16-28 lb in
© 2013 General Motors Corporation. All rights reserved.
xTooltipElement
Service Information
2002 Pontiac Firebird [2g2fv32g722100402] | Camaro, Firebird (VIN F) Service Manual | Driveline/Axle | Rear Drive Axle | Specifications | Document ID: 718716
--------------------------------------------------------------------------------
Pinion Bearing and Differential Bearing Preload
Application
Specification
Metric
English
Differential Assembly Backlash
Drive Pinion and Ring Gear Backlash
0.13-0.23 mm
0.005-0.009 in
Drive Pinion Bearing Preload
Rotating Torque with New Bearings and New Oil Seal
1.7-3.4 N·m
15-30 lb in
Rotating Torque with Used Bearings and New Oil Seal
1.0-1.7 N·m
10-15 lb in
Total Preload with Carrier Installed
Rotating Torque with New Bearings and New Oil Seal
3.6-6.2 N·m
32-55 lb in
Rotating Torque with Used Bearings and New Oil Seal
1.8-3.1 N·m
16-28 lb in
© 2013 General Motors Corporation. All rights reserved.
those values are with the entire axle disassembled.
pinion bearing preload on new parts is 15 to 30 lb-in with just the pinion installed, no ring gear & carrier installed. and the total preload you listed refers to the rotating torque on the pinion nut with the ring gear & differential installed but no axles. this value is slightly higher than just pinion bearing preload because it accounts for the preload on the carrier bearings also.
the correct way of replacing the pinion seal is a matter of cost. the truly correct way is to disassemble everything, put in your new seal, and use a new crush sleeve when installing the pinion. then you set pinion bearing preload to the value specified for used bearing, 10-15 lb-in. then install the carrier and verify preload on that is within spec.
other ways of doing the job are to mark the position of the pinion nut, then tighten to the same spot after installing the new seal, and then measure pinion bearing preload. and you can do this with the carrier removed or installed. if it's left installed then you want to remove the axles so you get a good preload measurement. leaving the axles in will cause extra drag, and if you leave the brakes and rotors on the ends of the axle that will guarantee a bad measurement and a botched job.
pinion bearing preload on new parts is 15 to 30 lb-in with just the pinion installed, no ring gear & carrier installed. and the total preload you listed refers to the rotating torque on the pinion nut with the ring gear & differential installed but no axles. this value is slightly higher than just pinion bearing preload because it accounts for the preload on the carrier bearings also.
the correct way of replacing the pinion seal is a matter of cost. the truly correct way is to disassemble everything, put in your new seal, and use a new crush sleeve when installing the pinion. then you set pinion bearing preload to the value specified for used bearing, 10-15 lb-in. then install the carrier and verify preload on that is within spec.
other ways of doing the job are to mark the position of the pinion nut, then tighten to the same spot after installing the new seal, and then measure pinion bearing preload. and you can do this with the carrier removed or installed. if it's left installed then you want to remove the axles so you get a good preload measurement. leaving the axles in will cause extra drag, and if you leave the brakes and rotors on the ends of the axle that will guarantee a bad measurement and a botched job.
Thats what I wanted to know. I may be replacing the posi unit over the winter so I will be able to do the measurement with nothing but the pinion gear installed and a new crush sleeve. Thanks for clearing up the confusion.
