Rear Axle Bearings/Seals

I'm about to replace the rear axle bearings on my '95 RMW. The right side is noisy and loose, which is why I have ordered a replacement axle along with the bearings.

The factory put bearings on the rear axles with a seal outboard of the bearing. I thought the bearings were lubricated from the fluid in the rear-end. But, some replacement bearings have the seal inboard of the bearing, which would keep rear-end lube from reaching the rollers. It would also allow water/dirt/brake dust to enter the bearing roller area and contaminate it.

Am I wrong about this? Are the factory bearings lubed with grease and rely on that only for lubrication?

The factory bearing rely on the rear fluid for lube.  Bearing savers might work instead of replacing your axles.  I had good luck with them on my Impala ss.

on the flip side, I had bearing savers leak, and went back to OE on a lightly scored axle with NO ISSUES. Did that on three wagons too.

Thanks for the responses. I thought lubrication was from the rear-end lube. Surprising the grease on the bearing saver type would last in that environment. Do you still put on the outside seal when using the bearing savers?

I have not yet torn it down, but know the right rear is noisy and you can wiggle the wheel indicating wear in the bearing area. The other side is quiet and tight.

I ordered one Dorman axle and have two Delco OEM bearings and seals. If my slide hammer works to remove the old bearings, it should be a fairly easy job. I anticipate crap in the axle tube on the bad side and I'll clean that out before re-assembly.

I had put synthetic lube in the rear-end last summer, thinking the noise may have been from the pumpkin, but, luckily, it's the axle bearing. Will put synthetic in again.

The Valvoline synthetic is sold as 75W-90 or 75W-90 for limited slip rears. Mine is limited slip. Is it really necessary to use the additive with the fluid made for LS rears?

I asked a friend who is a GM Master tech about axle saver bearings, he told me not to waste my time as they will leak. I figure new axles, bearings, seals and all when I regear the 8.5 on my truck just so I don't have to do it over.

How about the LS additive? Is it necessary with the Synthetic specified for LS rear-ends?

I've used those axle savers fine...but obviously going new axle and oe bearings is always better.

I use two bottle of LS additive ALWAYS. Used to get the little GM bottles, but now I just use the Trans X (little blue squeeze bottle) from the parts store. If the gear oil says "LS additive"...thats great, but still use the other bottle additive. You really need that or you will hear it once that rear heats up.

Tore it down today, put in the new bearings, seals, and replaced one axle that showed wear on the bearing surface. Dorman axle is $102 with free shipping (Prime) from Amazon. It comes with wheel studs, bearing, and seal.

Removing the seals is not hard, but pulling the bearings with a slide hammer is not easy. I have a fairly hefty slide hammer, but was really tired by the time the bearings were out.

I used Valvoline Synthetic 75W-90 for Limited Slip differentials with no LS additive. Used exactly two bottles. Will report on whether there is any chatter. If there is, I'll add the Trans X product.

The wagon is now very quiet on the highway!! No chatter with just the two bottles of 75W-90 Synthetic lube with no additives.

Now, if that rear cover doesn't leak, I'm done. I used black RTV over the old gasket.

brokecello wrote:

I've used those axle savers fine...but obviously going new axle and oe bearings is always better.  

I use two bottle of LS additive ALWAYS. Used to get the little GM bottles, but now I just use the Trans X (little blue squeeze bottle) from the parts store.  If the gear oil says "LS additive"...thats great, but still use the other bottle additive.  You really need that or you will hear it once that rear heats up.  

You were right!! All is OK until the axle warms up after a few miles. Then, especially backing up, there is a lot of "creaking" going on from the posi.

Not to worry, however, I'll add the additive. Still enjoying the quiet ride I hadn't experienced for a long time with the bad right rear bearing.

I put one 7 oz. tube of TransX in the diff last night. Noise problem is gone!

Thanks.

I have a 10 ft steel pipe I slide through the axle and hit it with a hand sledge on the opposite side and the bearings just fly out of there, lol

Trans X FTW

I thought of that! A 1/2" black pipe would work fine. By the time I got done pulling on the slide hammer, I wish I'd have had a pipe like you describe!

Sure is nice not having the bearing noise on the highway!

Quick question. Sorry for the hijack.
I know there are different size differentials for sedans. 7.5, and 8.5. Is this also the case with wagons? I have always been under the impression that only the 8.5 was used in all wagons. I ask because I have to order axle bearings and seals. The pumpkin looks like a 8.5 as it is round, but the code is GM8/2.56. Everything I see on the web says the 2.56 is only in a 7.5 pumpkin.

It;s just an 8.5 10 bolt gm rear end,..

phantom 309 wrote:

It;s just an 8.5 10 bolt gm rear end,..

That is what I figured. Thanks Nick.

Aren't the wagon bearings bigger than the sedan 8.5s?

jayoldschool wrote:

Aren't the wagon bearings bigger than the sedan 8.5s?

I am not sure. Rock auto list with 11" brakes, or 9.5" brakes. So now it is about brake size. Others say sedan or wagon. I would assume that all wagons have the bigger brakes?
I guess if you had a tow package, or B4U sedan you would really have to watch out what you get.

You can check Rock Auto for part numbers of wagons vs. sedans. If they are different, the bearings are probably larger. The wagon axles are an inch longer than the sedan axles.

All wagons have the bigger brakes.

jayoldschool wrote:

All wagons have the bigger brakes.

Thank you. This is the first time I have owned a wagon with 2.56 gears so while I was 95% sure all wagons used the 8.5, and 75% sure all wagons used the bigger brakes, you and Nick confirmed it. So now I feel confident in getting what I need.
Thanks. And I am sorry to the original poster for hijacking his thread. I just figured since my questions were related there was no sense starting a new thread.

@Bocoogto: rear cover not leaking?

jayoldschool wrote:

Aren't the wagon bearings bigger than the sedan 8.5s?

Yes