Rear axle seal

**Mike M.** · May 29, 2004, 08:43 PM

Re: Rear axle seal

remove the leaking rear axle bearing from the axle and take it to the local bearing and transmission shop(Applied Indust. thechnolgies is the outfit here on the east coast) and they can measure your old bearing and provide you with a sealed bearing that'll solve your leak. doubt "missing" o -ring will fix the leak. good luck, m ike

**John M.** · May 30, 2004, 01:35 AM

Re: Rear axle seal

Hi Mike,
Hows life out there on the left coast? First things first, The leak is probably from a bearing seal failure and probably not from the O-ring. Also, ANY new bearing you put in right out of the box WILL fail again after just a few thousand miles! The source of the problem is that the bearings sold for many years are not the same configuration as the original bearings. The original bearings were open to the rear end lube and were sealed at the outside of the bearing with the lip oriented to prevent lube from migrating to the brake drum area. All the replacement bearings, are sealed from the rear end and the seal is oriented to prevent the lube from entering the bearing!!! After a few thousand miles, the factory grease starts to dry up and the bearing starts to heat up. When this happens, the seal will start to leak from the high bearing temperature melting the seal. Now, the bearing gets the lube it has been longing for, but it is too late since now there is nothing to keep the lube from flowing into the brake drums. If you pull your axles and take them to an automotive parts house or machine shop, the chances are that the new bearings will be installed as they come out of the box, and the cycle will start all over again!
There is however, a very simple process that will assure long seal life.
First, you will notice that the bearings sold today are sealed on one side and have a dust shield on the other side. Pry the dust shield off and discard it.
Now you will need to remove the seal from the bearing and turn it around so that it is on the outboard side of the bearing and has the lip seal oriented to seal lube from leaking out to the brake area. I have been very successful in removing the seals and being able to re-use them by using a small pin punch and driving the seal off by punching between the balls of the bearing. If you damage the seal, don't worry, as you can buy new seals at your local Auto parts store. You can now have your local machine shop press the bearings on as normal, and you can be assured of long seal life. One other little tidbit of info. The original bearings were .900" wide and had a .10" thick spacer behind the bearing, while all the new replacement bearings are 1.00" thick and you must remove the spacer if it is there to prevent damaging the bearing retainer plate when boting it down.

Regards, John McGraw

**James F.** · May 30, 2004, 01:26 PM

Re: Rear axle seal- John

With deep respect for you and your vast Corvette knowledge, I must disagree with you on the rear axle bearing issue. I recently replaced one axle bearing at the time I replaced a '56 pumpkin (bearing looked original,I think it was, if so it has 99.900 known miles and between the races were "loose" ). I made my choice approaching the bearing replacment issue after doing a lot of "history" research on Chevy rear axle bearings.

IMO a lot of rear axle bearing confusion was a result of one or several of the large Corvette parts venders selling axle bearings not originally intended for Chevy rear axles. Dale P.'s solution to this bearing issue (which was as you stated 1.00 tk - and Dale requested all your unused .100 tk spacers) was to modify the seals. These bearings were to be modified as you stated. This modification may have been true for this particular bearing probably because it was not specifically intended for a Chevy rear axle. I ordered from NAPA (I have no connection with, yada, yada) a '56 Chevy rear axle bearing RW 507 ER. It was .900± tk and also contained a .100 ring. Dimensionally it was identical to the bearing I was replacing. It was sealed on both ends, the end near the "O" ring with an oil seal and on the other end what I'll call a dust cover.

The 1955 rear axle (ball) bearing is open to the pumpkin side and the 55 Chevrolet Service Manual illustrates this fact. Plus, I have a spare used '55 axle which proves this is the case. However, the '56 Chevrolet Service Manual states,"The rear wheel bearings for the 1956 Chevrolet passenger cars are the permanently lubricated type. The bearing is lubricated, then sealed on manufacture and needs no further lubrication for the life of the bearing. Previously, wheel bearings were lubricated with a splash type system within the axle housing." (Rear Axle and Suspension 4-1)

I noticed the "O" ring end of the bearing always indicated the end where the oil seal installed. There are many pictures of axle bearings (I also referenced a '58 Chevy Service Manual), most do not clearly show enough of the oil seal but the pictures are clear enough to see the "O" ring. The location of the "0" ring indicated the oil seal would be sealing off the diffentrial oil.

The two man machine shop where I had the old bearing pressed off and the new pressed on the co-owner said (generally) he would never press an "open to the diffenrtial" bearing on any axle. I used a specific rear axle Chevy bearing and respected the '56 service manual, and like sitting in a school history class learned a lot along the way. Still friends I hope! Regards,

**Mike M.** · May 30, 2004, 02:32 PM

Re: Rear axle seal

Joh: i replaced the axle bearings in my 54,57 AND 61 with sealed bearings i got at the local bearing store(applied ind tech) after i took in the originals for exact replacements. the 54 has over 40k miles(6800 toBend and back in 89) and the 57 has about 10k miles( lot of 1/4 mil;e runs as well as autoX) the 61 has about 1000 miles on it. haven't heard any bearings singing yet but will be on lookout. i hope you and i are around in 25 years so i can side with jim but who knows. regards, mike

**John M.** · May 30, 2004, 04:09 PM

Re: Rear axle seal- John

Jim,
As you are aware, there were not many things that Dale and I agreed on but this was one of those issues. While I do not doubt that your car may have had sealed bearings,and that those bearings may have in fact been original, I do not believe that later cars used sealed bearings. My 60 still had the original bearings in it, and they were open to the rear end lube. I also have an original GM bearing instruction sheet that clearly shows that the seal was located at the outboard position. John Hinkley sent me this instruction sheet several years ago when this question first came up in my mind. I would also agree with you that the 56-57 bearings are .9" in width, but all the 58-62 bearings that are being sold now are 1.0" in width, or at least they are in the parts stores in my area of the country. In any event, this is just something to check before bolting the retainer flanges on. Don't ask me how I know that this can ruin a set of bearing retainers!

Jim, I would never be mad at someone who expressed a different opinion than me, and especially you. You have always been a gentelman and have never ridiculed my lack of knowledge on 56-57 cars when I was foolish enough to open my mouth when I didn't know what I was talking about. I have never heard you utter an unkind word to anyone in all the time I have known you, and this is a rarity in this day.

My thoughts are that GM changed to an open bearing on later models to combat a high failure rate of either the bearings or the seals, but this is only conjecture on my part and I have no other documentation to prove this. GM has used axle bearings that are open to the rear end lube and still do to this day on most of their differentials.
below is a link to a scan of the bearing instruction sheet.

Still friends!

Regards, John McGraw

http://www.villagephotos.com/pubbrow...elected=893908

**James F.** · May 30, 2004, 06:11 PM

Re: Rear axle seal- John

John,
Thanks for the friendly words. Yep, I too had John's instruction sheet from Hyatt Bearing to consider. And it compounded my final decisions how to mount the '56 bearing. The blueprint woulld seem to indicate that Hyatt bearing was .900± tk. I bow to your knowledge on 58 - 62 Corvette rear bearings being open and replacements (now) being 1.00tk.

'58 Chevy Service Manual 5-3,4 drawings (somewhatless than totaling convincing) would seem to indicate the oil seal faces the differential side. The section has instructions how to remove the bearing and seal, and how to repack the bearings (with 1 1/2 teaspoons of grease, their words) and install a new seal. Unfortunately it doesn't mention which end goes toward the hub.The two pictures suggest the sealed end toward the differential. Regards,

Rear axle seal

Rear axle seal

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