56 Rear Axle Bearing

[Terry D.]

After replacing the driver side rear axle bearing ( failure after 7000 miles) for a friend we were wondering why the failure. Everything seemed to be in order, however after driving the car on the freeway I checked wheel hub with an IR gun and found that the drivers side is about 45 degrees hotter that the passenger side. (145 to 100, this on a 60 degree day)Made sure the brake shoes were not dragging, inspected everything we could think of and found nothing. The rear end is a 56 with a 62 posi third member in it. Any ideas as to why one side runs so much hotter than the other. Is the driver side not getting lubricated for some reason?
Terry

[Mark P.]

Re: 56 Rear Axle Bearing

Wasn't the original rear bearing in a 56 a sealed bearing? I replaced what I thought were original bearings in my 56 and they were sealed. If so, the temperature could be an issue, but not the lubrication component.

Mark

[John N.]

Re: 56 Rear Axle Bearing

After replacing the driver side rear axle bearing ( failure after 7000 miles) for a friend we were wondering why the failure. Everything seemed to be in order, however after driving the car on the freeway I checked wheel hub with an IR gun and found that the drivers side is about 45 degrees hotter that the passenger side. (145 to 100, this on a 60 degree day)Made sure the brake shoes were not dragging, inspected everything we could think of and found nothing. The rear end is a 56 with a 62 posi third member in it. Any ideas as to why one side runs so much hotter than the other. Is the driver side not getting lubricated for some reason?
Terry

Is the left axle to long? The left axle may be riding against the cross shaft in the center section. You can check the clearance by puting clay on axle end and after installing and removing axle, check clay thickness. You probably want .080 to .120 clearance. This is often a problem with the left axle and sometimes with the right when changing components on C-1s. A machine shop can face the axle to increase clearance. Let me know what you find.
Regards

[Mike M.]

Re: 56 Rear Axle Bearing

as i recall, the 55 to 57 chevy pass car axles are a tad longer than their respective corvette cousins and if a pas car axle is used, it has to be shortened as john posted previously.have a buddy here in town with a 61 vette with 383 ci sbc making close to 600 HP. he regularly breaks axles and says the pass car axles are a bit long.mike

[Terry D.]

Re: 56 Rear Axle Bearing

Does anyone have a picture or diagram that shows how to measure the axle length? I see in my parts book that there are several different lengths.

Terry

[Gary C.]

Re: 56 Rear Axle Bearing

Terry, measure the axle lengths from the bolt side of the wheel/hub flange to the end of the axle shaft. Use a square on the axle shaft end to keep the tape square. Thought I had a photo, but can't locate it. Will post it later if I can find it. Posi axles were shorter than standard axles. In '57 there's 1/4" difference in lengths between standard and posi axles. Don't have any experience with '56. Below are axle lengths from the Parts Books. Gary....

P&A Group 5.420 - Axle Lengths
'56 Corvette: standard L Axle=28 15/16", R Axle=30 7/16"
'57 Vet/Car: standard L Axle=28 11/16", R Axle=30 3/16"
'57 Vet/Car: positrac L Axle=28 7/16", R Axle=29 15/16"

[Chuck G.]

Re: 56 Rear Axle Bearing

Common problem putting a posi rear end into a 55 and 56 Chevy passenger car. I assume it's the same for the Corvette. I don't think posi was available till 57 in the passenger car or Corvette.

I have a 4.11 posi that I'm planning to put into my 56 Chevy hot rod. Waiting till I get an overdrive automatic installed before I so the switch over. I'll need to "grind" my axles for the installation.

Original 55 and 56 passenger car and I ASSUME Corvette axles need to be shortened 1/8 inch each if you're using a 57 and up posi rear end.

You can grind 1/8 inch of the end and "deburr" it.

Check with some 55-57 Chevy hot rodders for confirmation. It's a VERY common problem.

Chuck