Changing axle seals and bearings...

[peppy]

I'm thinking of changing rear differential fluid. As part of the process, it requires taking off the rear cover. And, I was thinking of changing the axle seals and bearings as part of the process. Anyone know what tools are required and where to get them?

Thanks all!
Peppy!

[Rileysowner]

From what I have read getting the cover off, taking out the pinion locking bolt and getting the seals out is all pretty straight forward. As far as I know a seal remover is not needed as you will be putting new ones in, so popping them out with a big screw driver should work, just be careful of the ABS stuff and don't damage that or other parts in there.

As for the bearings. I have no idea what would be needed to get them out. It sounds like some sort of puller would be needed. Now if I could get one that will pull the rear bearings and also pull the front bearing races, I would buy it simply for the convenience.

Since I have not done the job on my van yet, take my information as the stuff I have gleaned from doing some reading, not information from personal experience. I am hoping I can get to the seals on my van this week, but work is keeping me busy catching up after vacation and when we got back our fridge had died and needed to be cleaned out. It is supposedly repaired now, but we have to find a way to get the smell of rotten food out. Add to that a fairly small exhaust job on my wife's mazda protege, and the axle seals may have to wait until Monday.

[LiftedAWDAstro]

First, I have to ask why would you bother changing the axle seals and bearings? Are they leaking? Are they worn?

If not, don't bother changing them as you could damage the new seal installing the axle shafts back in. If you need to replace the seals, post back up and I can give you a run-down on what to do.

[peppy]

Well, since I am changing the differential fluid, I though Id change the oil seals, which requires the same procedure: taking the rear cover off. Its a 1991 Astro, and the seals probably have never been replaced....

Thanks,
Peppy!

[LiftedAWDAstro]

The seal replacement job is a bit more involved than just changing the diff fluid. I would inspect them first and if they are wet with oil, change them out.

To change the seals:
1. Jack the van up and place on jack stands.
2. Remove both wheels/tires.
3. Loosen the fill plug to make sure it will come out to re-fill.
4. Open diff cover and drain old oil.
5. Remove both brake drums.
6. Turn diff carrier to locate center pin retaining bolt, remove bolt.
7. Carefully pull center pin out.
8. Now push both axle shaft in to remove "C" clips.
9. Remove axle shafts.
10. Replace seals.
11. Put axle shafts back in lining them up with the splined side gears.
12. Put the "C" clips in and push the axle shafts out.
13. Put the center pin in, line up the retaining bolt hole and install the retaining bolt WITH lock-tite on it.
14. Put RTV sealant on the cleaned up diff cover per the directions on the tube.
15. Put cover on and tighten the cover bolts.
16. Fill with oil.
17. Put drums and wheels/tires on and torque lug nuts to 100 ft-lbs.

[peppy]

Are you sure that RTV needs to be used on the gasket? It seems that just like the tranny gasket, the rear differential cover gasket does not need any RTV.

Thanks,
Peppy

[LiftedAWDAstro]

If you use a gasket, then there is no need for RTV. Most people just toss the single use gasket from the factory and use RTV in place of the gasket.

[GEJ]

I have used "form-a-gasket blue stuff for things like this before.Not sure if it is any better or worse than what Lifted suggested.Just my two cents worth.

[peppy]

Do I fill the rear diff with diif fluid until it starts to leak out?

Thanks all!
Peppy!

[Rileysowner]

Yup, just fill it up until the oil starts to leak out. I know some say you should not worry if the van is level, but when I had mine jacked up and on the 6-ton stands I could sit up under it and their was no way I would get the amount of oil I needed it. So I lowered it to a more reasonable height that was closer to level, and that worked well. I left the wheel off and could get in through their easily enough to fill it.

Did you do the bearings or just the axle seals?

[peppy]

Just the axle seals. The bearings looked ok. Very easy job.

[Rileysowner]

Yup, once you get the fill plug out and the pinion locking bolt (if it was well stuck like mine was). After that it is so simply it makes one wonder why they charge so much to do it at the shop.

[peppy]

They charge a lot at the shop because people dont know how easy it is!

I bet the easier the job, the more they charge! (They laugh all the way to the bank!)

[skydog]

I have a 2005 Astro van 2 wheel drive and just had the rear outer bearings and seals replaced but that did not fix the problem of when I slow down, I can hear a growling noise from the rear end. I think that I have positrac and am wondering if that may be a problem. With a stethascope I can hear that the center bearings sound noisy and the new outer ones sound good. I am wondering if the noise is from inside the differential or the inner bearings. Should I be changing the center bearigs or do I need a complete rebuild. I have 146,000 miles on the van. How much should I expect to pay for the fix.
Thanks, Bob Grant

[LiftedAWDAstro]

Most likely the issue is the pinion bearings. Shouldn't be more than $2-300 for a shop to do it.