Replacing rear wheel bearing and seal

Guys, question about this. I have a leaky rear wheel seal and I really need to get off my own lazy rear and fix this before the diff runs dry.

Looking at the procedure in the book using all the special GM tools seems just fine, I guess the real complication for me is that having to put the car in the center of the garage in order to get enough clearance to pull the axles completely out, means all the other cars need to be left out while I do this, so I don't want to get into a situation where the Buick is stuck on stands for a week because of some problem.

My primary questions are this, then: first, what tool(s) should I get? Something like "the Harbor Freight slide hammer does (or doesn't) work" would be good to know.

I want to do both sides and change the bearings too, because may as well do it while it's apart, right?

I have the SKF "repair bearings" that are bearings and seals in one. I can use that, or if that doesn't work I also have on-hand the plain seals themselves.

There's pretty serious inertia on my side, but I don't suppose there's any danger of the car toppling off stands while I slide-hammer the bearing out, is there?

I dunno, any other tips from the crew?

just change the seal,..

Not sure about the HFT Tool, but just rent the one from your local auto parts store, do it, and return it.

It's not that hard of a job.

You may be replacing the entire axle. Check for axle wear at the bearing. If the axle is worn at all, or it has a cut where the seal runs, it should be replaced, and a new set of bearings installed as well. Usually the axle is worn, which is why the bearing is leaking in the first place. If you need to replace the axles, get Moser units. They are about the same price as the Chinese and Indian ones, are better quality, and are made here in the US. If you want to get used axles from a junk yard, only use the driver's side. They have less wear than the passenger's side.

Thanks guys - I think Autozone rents the OTC puller set, supposedly that should do the trick.

And yes I may just replace the seal.

But to Fred's point- the SKF repair bearing is supposed to address that exact problem. It puts the wear surface at a slightly different point so that if the axle is grooved due to bearing failure you can still use it. That's why I got them, I figured if the axle was damaged I'd have a way to fix it on-hand rather than having to get parts and wait.

Supposedly these cars have a problem with lubrication out to the wheel bearings due to gasket problems or something along those lines.

The issue is more along the lines of using the axle as the inner bearing race. There are rather high forces applied to the bearing and axles, and the axle is only surface hardened so that they do not snap because of being brittle. If you wear through the hardened outer shell, the axle is much softer. You can not just replace the bearing (without changing the wear surface), because the axle is part of the bearing. The passenger's side receives most of the torque, and does most of the driving of the car forward, and consequently has the most wear.

Replacing just the seal will not cure the problem, because the axle no longer sits in the center of the seal due to the decreased diameter of the axle and subsequent displacement inside of the bearing rollers when rotating the axle to move the car.

I have heard mixed reviews of the repair bearing. If you feel comfortable with it, use it. I do not feel comfortable with the repair bearing, because there are usually other issues with the axle when the bearings are worn to the point that the seal leaks. A cut where the original seal rested, is a stress concentration point, and can be the place where the axle breaks under load. Even the groove resulting from the original bearing can be a stress concentration point, and cause the same results.

Fred - you don't happen to know the part numbers for the Moser axle set? I assume it's probably one of the pickup truck axle sets. I'd like to investigate that option.

They should have a reference for the wagon axle. They have made them before. You have to call them and talk to someone, because it is not a stock size. You may have to measure your axle, and send it to them.

Axle shaft at the bearing is larger than the sedan, 1.6" for the wagon. Dorman lists the length of the axle at 31-13/16" and 30 splines. The outside diameter of the bearing is 2.85".

Thanks Fred, will do.

If any of you guys have a wagon axle out of the car and validate the dimensions that Fred and Dorman have listed, that would be helpful. I can't pull the shaft out and wait a week with the car blocking the whole garage

This is the sort of info that's super helpful beyond the published stuff in the manuals. I didn't realize that the axle face itself was the inner race. I'd have hated to open this thing up only to find that I need a whole new axle anyway.

I replaced the axles on my 91, and I did not realize the finer points when I started out. Remember to put the modifier for the limited slip in the rear when you replace the gear oil. Put the modifier in, then fill it with oil.

Ok, will do. Moser wants $370 for a set of axles. Ouch.

It will probably cost you about $300 for a set of Chinese axles.

The Dorman 630118 "kit" is $100 each from Rock Auto. No idea who makes them for Dorman. They have a Dana shaft as well (alone) for $90. No clue as to who makes those either.

I will guarantee they are made in either China or India. You forgot to include shipping on the cost of the Rock Auto items.

Well, true. With shipping we're looking at $228 for a set of Dormans.

That looks awfully low for shipping two axles. I expected about $50-70. I use FEDEX, and $50-70 is what it would cost me.

Well, so the amount of money I'm looking to spend here ranges from close to zero (I already have the repair bearings) to about $400 if I replace the axles too.

I got the car up on stands and scoped out the diff area. It's leaking. I'm not sure if it's from the input shaft side or the cover gasket, but it's externally well lubricated. I may be in for more work than I thought.

One nice thing however, thanks to all the leaks everything underneath seems well rust-proof. The gas tank looks fine, and I know those have a tendency to rot out.

The gas tanks are plastic on our cars.

There are some tricks to resealing the rear without a major overhaul. The FSM gives you instructions, and they are posted a few places on here and impallassforum.com. There is a currently active thread on the ISSF about leaking rears.

Aha, plastic doesn't usually rust. Maybe it's the straps I'm thinking of. Regardless aside from the spare tire area it looks reasonably solid under there.

Anyway, yes, I'll have to check that out. There's some good info there. Looks like changing that input seal won't be too bad if that's where the oil's coming from.

I think I've got a physical arrangement that may work without causing too much disruption to everyone, so I can pull the axle that leaks out first (driver side) and check the condition of the components before making a decision.

You need a 32mm socket to remove the yoke nut.

Ok, that's good, I have sockets that size. Be more worried about the loose nut behind the wheel as they say.

I took another look and the wet streak appears to run from the input shaft and collecting down at the flange where the cover meets it. Hopefully that means it didn't run too dry.

I rented the slide hammer kit so I should be able to get the axle out this weekend and see what's going on there. I wonder if it's bent, too.

Probably not bent.

It doesn't look so. Rotating the wheels by hand gives no obvious out-of-round indication, although a runout gauge would really be what you need for that.

There doesn't seem to be any "wear limit" in any manual I've read, so I suppose if the axle has any sort of groove at all that it needs to be discarded.

Also both wheels rotate the same direction, so the LSD isn't totally destroyed at least

I believe you can check the LSD with a torque wrench. I think the breakaway torque is 65 lb. ft.

Yeah I saw there's a procedure in the FSM with some special contraption that you attach to the lugs and turn with a torque wrench!

Finally this morning I was able to get the cover off. I picked up a pair of air-hydraulic jacks to use as a makeshift lift, which works a lot better than putting a corner at a time on stands. So far anyway.

The cover was RTV'd on, so someone was in there at least once before. About 2 quarts of oil came out which was a relief since I was afraid maybe it was really low. Seems OK in there to me, but this is the first one of these I've seen in the flesh.

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Open

there is a plug you can pull to check the oil level,...

yours a 2:93 posi?

The reason they use RTV is because some of the gaskets are not made correctly.

Yeah, I didn't check it and I probably should, but with it leaking gear oil onto the brake shoes I guess the level wasn't my biggest concern.

Yeah it's got the GW9 and G80 2.93 posi.

I got the lube locker gasket, as well as a regular fel-pro one, so we'll see if the lube locker stuff is any good.

There's grease all over everything back there. The exhaust too. May explain some of the strange smells. Also confirmed that someone did indeed put Flowmasters on it, as if the sound wasn't enough to tell. And I noticed that one of the rear springs isn't on its seat, and it actually is touching the shock.

I noticed two things that I was wondering about. The trans is in neutral- it's much easier to turn the diff in the forward direction than in the reverse direction. Also it makes a continuous squeak when being turned by hand forward. Seems to be coming more from the front/input side.

The squeaking could be a universal joint.

lamune wrote:

Yeah, I didn't check it and I probably should, but with it leaking gear oil onto the brake shoes I guess the level wasn't my biggest concern.

Well you n i are certainly different on that issue,.

If i have a leak,. i like to keep the vital fluids topped up so the machinery doesn't fail from lack of lube,.and keeps going till i can get around to repairing the leak,..
but thats just me of course,.

I had to help a guy change the dana diff in his dodge truck a while back,.

conversation went like this a month or so prior,..

" The leak has fixed itself,..."

Nick said,. " fixed itself? thats funny right there,.. thats gonna cost you a pile when the rear burns up,."

"NAAAAHHHH,... its a dana,. it'll be fine,..."


The 'I told you' so moment was priceless,.

wow! no rust!

Fred: You know what, I think you're right. The squeak does seem to be coming from the U joint.

I guess that's got to get changed out too. There's a few choices on replacements there, any specific recommendations?

Nick - funny you mention that. Well I'll say this, when I noticed the leakage I cleaned off the brake shoes, and with the car sitting (which it does most of the time) they got leaked on again, so I knew the fluid in there was at least up to the level of the axle tubes. But that's a funny story. I love it when leaks like that simply "go away". yup.

Not much rust under there. Motor oil, transmission fluid, hypoid oil- makes a really good rustproofer!
I did see the parking brake cable isn't sitting in the clip and is up against the sheet metal. Looks like it rubbed the undercoating and paint off in a few spots, but it's covered with grease too so the bare metal is shiny.

I'm going to check the repair bearings and see where they ride, and more importantly where they seal. But assuming that's out of the picture I think both axles may need replacement. The passenger side one has a really obvious pitting ring, the drivers side has a few pitted spots.

Not sure what the JY scene is like in Seattle, but if they have some wagons, you can do like Fred suggested and get some DS axles if they have a low mileage wagon.

If your diff was leaking at the yoke, they sell a yoke repair kit. Very easy to do.

Very rarely do you find a wagon around here. Most of them ended up in Florida, it seems. I wonder why?

There is a streak of oil going down the centerline of the housing, so unless oil was leaking up, the yoke oil seal is probably leaking as well. It sort of looks like oil was being flung all over back there, which also seems like a leaky yoke. I have the seal, I'll replace that too.

Now that I see how this all goes together, it looks like the repair bearing doesn't exactly ride on a totally different surface- it overlaps, at least according to my measurements.

So now it's a decision between getting some Dorman axles or having some really nice ones fabbed for me. Anyone use the Dorman axles? Any comments on them?

I have plenty of other things to do while I'm waiting for some axles. And if I can figure out how to get to the brake line up on the top of the diff I'll change that out too. I can't figure out how to get in there just yet.

I have the Dorman axles in my red wagon, but I have not looked at them for about 12K miles. As far as I know they are not leaking at the seals. I will be upgrading to Moser axles this fall, when I get the 454 installed.

Well, if I were doing something as awesome as going big block I'd certainly opt for the Moser axles!

I need to fix this too. The outer tube is dented. The grease trails are pretty obvious, though I think on this side a lot of it is motor oil from when the oil cooler line popped off.

That is an original air adjustable shock, and there are not direct replacements available. You can get adaptors for other air shocks. To keep your spring on the seat, use a couple of tiewraps. Rotating the spring so that the "open" end is toward the shock may help too.

Thanks for the tips Fred. I have the AC Delco air shocks on hand, which came with an air line and some fittings and stuff. I guess you're saying the fitting is different and won't simply go on as it does on the originals.

They probably will need a little fiddling to get them to work with the system. There are some write-ups on the ISSF about them.

Ok, we'll see how that goes. Since I'm replacing the springs anyway, I should have good access to get the fittings on the shocks.

I'm going to have the prop shaft removed, so I'm also thinking about removing the springs and shocks on both sides and letting the whole axle hang down so I can get into where the rear brake line to see if it needs changing. Unless that's a bad idea and something will break if I do that.

You should detach the flexible line before dropping the axle.

Here's what a Dorman Indian-made axle looks like. Seems fine, there's quite a bit of machining grit and bits on it, so it's going to need a cleaning before installation. I have no intention of using the Chinese-made bearings and seals.

The studs look like they're going to take quite a bit of force to install. I always thought the holes in the axle face were splined but that doesn't seem to be the case. Can I use a vise and socket to push these in, or will I need to have a shop do it with a press?

A BFH works best,.

That's good! I do have a BFH!

Making progress, got the new springs and shocks installed and the axles now have wheel studs in them.

Getting the shocks out was a lot harder than I was anticipating. Well, the first one anyway. Once I figured out the process the second one was relatively simple. Also there's just slightly more room to work on the passenger side which also helped.

More progress. Diff is reassembled and refilled. The front oil seal was more of a pain to do than I expected. My seal puller snapped in half trying to get the seal out. Then, finding something the right size to seat the new seal was a bit of a challenge (ended up using a 2" EMT conduit fitting of some sort along with a piece of 2x4)

Wanted to pass this along/ask about the turning torque of the flange. I measured it before removal, it was about 8 in-lb. When I got it back together I tightened the nut just shy of where it was, and when I measured the torque is was now 18-20 in-lb. (oops?) Since I know you can't back it off I just left it that way. After buttoning up and refilling the diff, I re-measured and got 10 in-lb. I guess I should leave it alone?  The nut is sitting about a 1/16th turn loose of where it was when I started.

I wanted to add that the lube locker gasket seems to be leaking.