Rear axle leak/resealing

[Knebel]

Hey..soooo i just took my drums off to adjust the brakes and check them cause my parking brake wasn't really gripping anymore... I found that on the drivers side, everything is full of oil. And i could tell it came out of the axle. Not the surface where the gasket meets the backing plate but the "inside" if that makes sense. I am working in a parking lot here and the FSM is not 100% clear on something.

In order to replace the axle shaft oil seal and retainer gaskets, do i need to take the bearing off? I dont have a vise or a shop... How much does something like this run for when having it done at a shop?

 

[Knebel]

I just read it could happen when the axle play is not adjusted right!? Coul i just replace the inner oil seal and readjust axle play?

 

[Big_John]

Yes, you will need to change the bearings to change the seals. You might as well do the other side at the same time.

Figure on around $100 for good Timken bearings and all the seals, depending on where you buy them. I think Dr Diff has kits that will give you everything.

You'll need some room and a press to do the job right and it sounds like you have neither. I had one done last year and it was $225 in labor. That will give you a ballpark cost. YMMV.

 

[Big_John]

I just read it could happen when the axle play is not adjusted right!? Coul i just replace the inner oil seal and readjust axle play?

No...

 

[1978 NYB]

There are plenty of shops that can press the bearings off and on for you. $200-$225 sounds about right. I agree....do both sides. Check the pinion seal for leaks while you're doing this. Replace the diff seal and gear oil too. I'm sure the brake shoes, hardware and wheel cylinders will be looked at or replaced. Turn the drums or replace them and you'll have a new rear axle assembly.

 

[Knebel]

Ugh... Yeah... And... Whats the cheap way of doing it? Lol i found the shaft seals but cant seem to find the backing plate seals anywhere. Is there a part number to those?

 

[1978 NYB]

Just replace the axle seals if you think the bearings are good. You'll have to replace the shoes too.

 

[Knebel]

Just replace the axle seals if you think the bearings are good. You'll have to replace the shoes too.

I would need to pull apart and inspect first. Normally... If i wouldnt have to do all that in a parkinglot, i sure would redo the whole damn thing. Problem is, i dont even have a workbench and also cant leave the car sitting overnight without an axle in it. So main goal is to stop the oil for now.

 

[1978 NYB]

Yeah, I hear you.

Good luck.

 

[Davea Lux]

This is not a job you can do in the parking lot. Put it back together and drive it home first. Most of the time, if the seals are leaking it is because the bearings have excessive wear and have hollowed out the grease seals. Poorly adjusted end play could cause this to happen, but it is already too late for your seals. Take out both axles and replace the bearings as required and all of the axle seals. Napa and other quality auto parts will press the new bearings for you cheaply if you buy the bearings from them. Do not bother with the low end Chinese bearings, they are not worth putting in, same with the seals. When you pull the seals, they have a number on them. You can cross reference the number in the National Seal catalogue to acquire the proper replacements. As noted in the posts above, the brake drums and backing plates will need a good cleaning. Do not bother trying to clean up you brake shoes they never work right once oil soaked. Use this opportunity to change the rear end oil and check the rear housing vent to be sure it is not clogged up. A clogged vent will also blow oil past the rear seals (they will still need to be replaced).

Dave

 

[polara71]

Ugh... Yeah... And... Whats the cheap way of doing it? Lol i found the shaft seals but cant seem to find the backing plate seals anywhere. Is there a part number to those?

Drivetrain :: Mopar 8 3/4"

 

[Big_John]

Just replace the axle seals if you think the bearings are good. You'll have to replace the shoes too.

You have to take the bearings off to do the outer seals... and that involves cutting the bearing retainer.

 

[polara71]

This all could be done in a day as long as the local shop knows you are bringing them the shafts .

 

[Big_John]

Drivetrain :: Mopar 8 3/4"

There ya go... and buy the Timken bearings. It's worth the $40.

 

[polara71]

There ya go... and buy the Timken bearings. It's worth the $40.

I agree , thats what I do ....

 

[Knebel]

Ok here is my plan: i just ordered a set with all the seals and gasket. When i have that, i will pull apart the axle and check what is going on there. If its just the seal that hardened, great, if not, i will put it back together and get the bearings replaced too. Then i gotta do the brakes too after that... I just don't like pulling stuff apart without having the material to at least seal it back up.

 

[Big_John]

Ok here is my plan: i just ordered a set with all the seals and gasket. When i have that, i will pull apart the axle and check what is going on there. If its just the seal that hardened, great, if not, i will put it back together and get the bearings replaced too. Then i gotta do the brakes too after that... I just don't like pulling stuff apart without having the material to at least seal it back up.

The only seal that you will be able to replace without removing the bearings is the inner seal. It might buy you a little time and you can repack the bearing, but the outer seal is shot too.

 

[Knebel]

The only seal that you will be able to replace without removing the bearings is the inner seal. It might buy you a little time and you can repack the bearing, but the outer seal is shot too.

Oh yes, i agree with you. What is your opinion on something i just read on an a-body site where it said "the outer seal is mainly to keep dirt and water out of the bearing, whereas the inner seal keeps the oil in"? And on the backing plate gaskets, do you know which one goes between the backing plate and axle housing? The foam one or the actual gasket material one? From the looks of it i would say the actual gasket!?

 

[Davea Lux]

Oh yes, i agree with you. What is your opinion on something i just read on an a-body site where it said "the outer seal is mainly to keep dirt and water out of the bearing, whereas the inner seal keeps the oil in"? And on the backing plate gaskets, do you know which one goes between the backing plate and axle housing? The foam one or the actual gasket material one? From the looks of it i would say the actual gasket!?

Foam one goes under the outer flange. The outer seal is mainly an exclusion seal to keep brake dust, water etc out of the bearing, you still should replace it.



Dave

 

[Big_John]

Oh yes, i agree with you. What is your opinion on something i just read on an a-body site where it said "the outer seal is mainly to keep dirt and water out of the bearing, whereas the inner seal keeps the oil in"? And on the backing plate gaskets, do you know which one goes between the backing plate and axle housing? The foam one or the actual gasket material one? From the looks of it i would say the actual gasket!?

Yes, that's true and why I mentioned repacking the bearing as the grease will have been thinned out by the gear oil. But if it lets that thick gear oil out, it's gonna let water and dust in.

Foam goes under the outside flange and the regular gasket goes under the backing plate.... But you can't change them without removing the bearing.