Replacing a pinion seal

[black92_tsi_awd]

Mine's leaking pretty bad, anybody got any recommendations or hints on replacing it.

I've got the Haynes book, but the instructions on "using an inch-pound torgue wrench to see how much torque is required to turn the shaft within the range of gear backlash" "This is the drive pinion preload" are a little confusing.

It then goes on to say that if the before and after torques don't match after replacing the seal, you have to add/subtract shim. I don't understand how replacing the seal would screw up the pinion preload. On top of it, the book list the flange nut torgue range as 116 to 159 Ft.lbs, that's a big range for something critical as setting the preload...

 

[4pistons]

It specifies that range to accomodate the full range of preloads from no shims to maximum. As long as your final torque is in that range and your preload is accurate you're good.

I've replaced seals before without worrying about the preload and have had no side effects at all. As long as all you're doing is changing the seal and not opening up the diff.

If you have an inch pound wrench measure the torque to spin the pinion before you remove the yoke and then when you reassemble creep up on the nut torque spec while checking with the inch pound wrench to match the original pinion spin measurement. You'll be real close.

Rick - '91 GSX

 

[black92_tsi_awd]

Thanks, doesn't sound too bad. Guess I got a good reason to buy a inch-pound torgue wrench!!

You measure the torque to just move the yoke, right up to the point before the tires move, right? Only the shafts movement during gears backlash.

 

[4pistons]

No, you want to measure the torque it takes to move evrything smoothly, although it's sometimes difficult to do when there isn't much room. You don't want to measure backlash with a torque wrench. The preload is the amount of pressure on the pinion bearings and you don't want too much or it won't turn freely and you don't want it too loose either.

Rotate the pinion smoothly through as much of an arc as you can and watch the reading on the torque wrench. You may have to do it a couple of times. The factory spec is for the diff only with nothing attached but it doesn't matter if you have axles or tires bolted on as long as your "before" measurement is the same setup as the "after". Just make sure your brakes aren't dragging.

Rick - '91 GSX

 

[black92_tsi_awd]

Thanks...now that makes sence!

The haynes book statement "within the range of gear backlash" just didn't make sence.

Thanks
Chris