8 3/4 pinion seal and rear axle collar adjuster

[mgm1986]

Hey folks, waiting for parts to get the motor back together so I decided to tackle the pinion seal leak.

I have the 742 case and a few things I need clarity on.

For the 742 case, is it true it should have a solid spacer with shims for the pinion and as such I should be able to replace the seal and reassemble without worrying about changing the pinion gear lash?

For the axle stubs, only the drivers side had a locking tab on the rear axle adjusting collar. Is it correct that only one side requires the locking tab on the axle?

Thanks for your expertise!

 

[413]

Yes both are correct.

You can still overtighten the nut. So mark the nut on the shaft so you are close.

Axles are butted up to a centering block so they both move as one, so only one side needs the adjuster. Have both rear wheels off the ground when adjusting.

It's not that hard to adjust, don't make it harder than it is by overthinking it.

 

[Cranky1]

Hey folks, waiting for parts to get the motor back together so I decided to tackle the pinion seal leak.

I have the 742 case and a few things I need clarity on.

For the 742 case, is it true it should have a solid spacer with shims for the pinion and as such I should be able to replace the seal and reassemble without worrying about changing the pinion gear lash?

For the axle stubs, only the drivers side had a locking tab on the rear axle adjusting collar. Is it correct that only one side requires the locking tab on the axle?

Thanks for your expertise!

When you adjust the axle end play, do it when the car is cold and iirc, you should have .013-.023" end play. I've always done it by feel even though I have a dial indicator and never had an issue. Just make sure you don't get it too tight. When the axles get hot, they do expand and will close up the gap. If you have a service manual, the numbers will be in it.

 

[volksworld]

the new pinion seal I installed 2 yrs ago was a rawhide one (NAPA? Rockauto? don't remember) and it still dripped a bit...when I installed the Sure Grip I used a rubber one from Dr Diff an it's been dry so far...iirc the earlier end play spec was looser than the later one so I picked a number that was acceptable on either scale

 

[john-9]

742 case uses shims to set the pinion bearing preload --no spacer -- remove your yoke ,,remove the old seal and clean the seal bore ,, install the new seal with some grease on the rubber seal lip ,, reinstall your yoke and tighten down the nut with loctite on the threads -- factory spec is 240 lbs/ft . as you tighten the yoke down to spec do it in steps of say 50 lbs/ft and give the yoke a spin back and forth each time ,,,, this helps to line up the bearing and race without binding them up ,,,,, as far as the lock tab ,,your adjuster to set the bearing end play should be on the RIGHT side axle ( passenger side ) only ,, if it is on the LEFT side (driver side ) someone switched the axles side to side from the original factory install. there is no lock tab on the LEFT side axle shaft.

 

[mgm1986]

All good advice for sure.

For others reading along, don't use an impact to get the nut back to where it was. You'll snap the threads off the pinion gear.

Time for a new gear set. That's what I get for rushing the job and not using common sense. Maybe this will tilt my decision to upgrade to a sure grip eaton setup and shorter gears than the 2.76.

 

[Cranky1]

All good advice for sure.

For others reading along, don't use an impact to get the nut back to where it was. You'll snap the threads off the pinion gear.

Time for a new gear set. That's what I get for rushing the job and not using common sense. Maybe this will tilt my decision to upgrade to a sure grip eaton setup and shorter gears than the 2.76.

How big of an impact were you using?? 3/4" drive? I've done a lot of work on 8 3/4's and have never done that but I don't use the big impacts.

 

[mgm1986]

Yeah, definitely too much torque from the 20v dewalt impact. I was half a turn from lining up my marks when it spun the nut clean off. A real shame, the gears look brand new. Now I get to learn how to rebuild the whole carrier.

I knew better and still went against my prior knowledge and instinct. A clear case of not learning from past mistakes.