Bearings in the rear...not good...

77palmbeach

New member
Jan 5, 2019
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Edinburg, PA
www.gmcmotorhomeworld.com
Cleaned up the rear wheel bearings... I thought they were ok, but I am thinkin not... guess I'm just going to order all of them... gotta find timken near me now...lol. then I need to figure out how to get the old races out... Guess that could be another source of the mystery howl...

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Yup those babies are done.....not so much the cages but look at the rollers.......how to get the inner races out you say? Brass drift or a big punch with a hammer, working both sides of the inner race ledge, from the inside out, as equally as possible....heck you could probably sacrifice an old screwdriver if you didn't have any punches as we aren't saving the races. [wear safety glasses please]

To re-install you can use a block of wood with a rag or something placed on top to protect the race, driving the new race in equally till your block is flush with the hub then you can use the old race to help tap the new one in place making sure that its bottomed in the bore PLEASE MAKE SURE YOU DRIVE THE RACES IN THE PROPER WAY>>>Take a picture of the old setup if you have to as a mistake here is gonna cost you"......i usually start out with the old race against the thin parts till it get bellow the surface just enough that i can flip it around them finish the job.....why flip it around [like it would be installed you ask?....well we may have to use that punch/hammer to get it back out sometimes so its easier to hit the wide side as opposed to the thin side of the old race.
 
You are going to throw out the old races anyway, so I take them to the grinder and grind the diameter down slightly so that they can drop into the place they came from and can actually spin. You don't need to take much off of the diameter to make this happen. Clean them up of grinding material. Then use them to press the new ones in. This has worked for me. JWID
 
You are going to throw out the old races anyway, so I take them to the grinder and grind the diameter down slightly so that they can drop into the place they came from and can actually spin. You don't need to take much off of the diameter to make this happen. Clean them up of grinding material. Then use them to press the new ones in. This has worked for me. JWID
I always like to do something similar when setting up gears in a differential too. It's so much easier to slip them on and off the pinion as needed when shimming, for example. My 20 ton press is covered and surrounded by old bearings and races, I almost never toss them out. They get used for pressing all sorts of things.
 
I'm doing bearings in the rear of my 76 currently. Not sure if I should start a new thread or just tag it on here, but after going round and round with the numbers on the parts interchange I found that according to AutoZone the rear bearings are the front bearings and inner seal to a 2wd 1976 Chevy C-20 with heavy duty brakes. They actually cross reference to a bunch of other makes, models, applications (the inners are used in a bunch of rear differential carrier bearings for instance, maybe even new trucks!) but the Chevy C-20 is the simplest way to find them imo.

The inners also can come as a set, SET45 , or buy the bearing and race separately.

Long story short; front wheel bearings and seal, 1976 Chevy C-20 with heavy duty brakes to go on the rear of the GMC. At least that seems to be right, if it's not I'll edit this post with an update.
 
When I had a bearing like that, my metallurgist friend identified it as corrosion. I have seen it since and every time there was condensation inside the hub. I still have not figured out what to do about it.
Matt

The bearing I just changed had moisture under the dust caps also. All the others were dry.
 
I just discovered a noisy bearing. No shavings, no visible pitting on the rollers. The nice black grease faded toward brown/rust color moving from outer toward inner. Then I see someone boogered the wheel seal when they installed it. The whole frame of the seal was dented and distorted. I'm going to chalk the water ingress up to that. It wasn't much, mind you. I saw no actual water droplets, but it's clear there has been some in there at some point.
 
I ordered all new bearings and races from Amazon 3 months ago..all were USA Timken EXCEPT the 15103S. It was labeled National, Made in Spain. I have not been able to source the made in USA Timken 15103S.
please post if you find a source.
Scott.