Leak from Rear End

[NoVA_87_GN]

I started working swapping out the suspension parts in the rear and noticed the rear end was leaking. I knew it was leaking before, but I assumed it was from the rear diff cover. It looks like it leaking from where the driveshaft meets the rear diff. Is this normal/simple fix? If so, any tips how? or will i need to take it to a shop to get it taken care of? Thanks for the help.

 

[SCOOBY DOO]

Pinion seal is leaking.

 

[Pronto]

Yup. Usually a little rust starts and it slowly eats the seal. The diff needs to pulled to get the pinion out. Depending on your abilities it can be done in your garage.

 

[1986 Buick GX1]

Yup. Usually a little rust starts and it slowly eats the seal. The diff needs to pulled to get the pinion out. Depending on your abilities it can be done in your garage.

Can the driveshaft be dropped out of the yoke, the big nut taken off and the yoke removed to replace the seal.
If rust needed to be removed, wouldn’t it be on the yoke?
I thought I remembered the seal rides on the yoke, maybe not? It’s been a while.
It seems the torque on the big nut is in the 200- 250ft/ lb range if you don’t install a new crush sleeve.
I think you want 5- 25 in/ lbs rolling torque to rotate the pinion shaft once the yoke is installed.

 

[Pronto]

Ya, if it's only the seal that's the issue. Here's a video.

If there is excess play in the pinion it won't fix that.

 

[NoVA_87_GN]

Anyone have the correct part number for a replacement?

 

[SCOOBY DOO]

Anyone have the correct part number for a replacement?

Try your friendly GM dealer.

 

[TurboWh1]

Just did one.... I might have seal part number laying around. I used a National seal from Advance Auto. The yoke does ride the seal. If your yoke is rusted or pitted badly, clean or replace it. Strange offers a chromolly option.

 

[NoVA_87_GN]

Thanks for the replies. Somewhat off topic, picked up a BRM suspension kit and I’m starting to tear into the suspension. Getting some of it out here and there, any trick to removing the front upper control arm bolts? Not much room to move around. Also contemplating swapping out the body Mount bushings, I can see the radiator core support bushings have split. Just don’t want to get too far down the rabbit hole.

 

[TurboWh1]

Pinion seal.... National 2043

 

[NoVA_87_GN]

Got an update, I have the rear end pulled and decided to fix my leaking seal. Picked up this one from Amazon:
GM Genuine Parts 26064028 Differential Drive Pinion Gear Seal
Pulled the old seal, cleaned up the area, put the new one in, tightened down the nut, poured some oil in the rear diff, looked good for a couple of days, just noticed it was leaking again. Don’t want to keep replacing the seal again if that’s not the issue. Any thoughts?

 

[Chuck Leeper]

Did you add a bit of sealer on the OD of the new seal?
Any pitting on the yoke?

 

[NoVA_87_GN]

@Chuck Leeper forgive my new-ness in asking these question, most of what i'm doing is my first go around.
Could you clarify what "bit of sealer on OD of the new seal?" is?
Am I using the right seal? It looks different from the one @TurboWh1 pics looks like.

 

[SCOOBY DOO]

I think Chuck means outside diameter. From a personal standpoint I woulda gone to my friendly GM dealer to get the seal.

 

[salvageV6]

I'd be checking the housing out for a tiny crack. As well as where the seal sits for any issues.
I'd probably try the GM seal as well.

 

[NoVA_87_GN]

So the seal I put in and the one pulled out look nothing like the the one that was put in while watching the video in this thread. looked on rockauto for comparison, looks like i put in an outer seal (left pic). Was it supposed to be an inner seal (right pic)? Thanks again for all the help.

 

[Chuck Leeper]

So the seal I put in and the one pulled out look nothing like the the one that was put in while watching the video in this thread. looked on rockauto for comparison, looks like i put in an outer seal (left pic). Was it supposed to be an inner seal (right pic)? Thanks again for all the help.

The seal on the left can go in but 1 way. The one on the rt either way.
If the lip is facing the wrong way, it'll leak.
Furthermore if the hsg vent is pooched it'll make the seal leak from pressure build up.

 

[IrvJr]

Got an update, I have the rear end pulled and decided to fix my leaking seal. Picked up this one from Amazon:
GM Genuine Parts 26064028 Differential Drive Pinion Gear Seal
Pulled the old seal, cleaned up the area, put the new one in, tightened down the nut, poured some oil in the rear diff, looked good for a couple of days, just noticed it was leaking again. Don’t want to keep replacing the seal again if that’s not the issue. Any thoughts?

I had the same issue, mine has just been seepage not dripping out. Continued after a new seal install.

 

[gnmaster2004]

I had the same issue, mine has just been seepage not dripping out. Continued after a new seal install.

I have had them leak through the splines. I used silicone on the yoke splines, fixed.

 

[TurboWh1]

Pull the yoke out, leave new seal and add RTV on spline/washer. Check out you tube. There are videos on it I believe