HELP! What rear axle do I have

[64Chevelle]

Hi,

I have a serious problem identifying the rear axle in my 64 Chevelle. It is not the stock unit, the last owner says he believe a camaro axle has been installed in it, but not what modelyear. It's got a differential unit.

From the pictures and info I've found on the net I BELIEVE it is a 70-81 10 bolt Camaro with 8.5" ring gear.

Unfortunatley, the numbers on the housing are next to impossible to read so I don't expect to identify it by that either. I have a few pictures though, I'm hoping that one of the wizards in here can work their knowledge magic :)

28037

28038

28039

[first64]

It is a 8.5", can't tell for sure about the camaro part. Can you read the castings numbers on the pumpkin?

Here is some more info:

.................................................. 1967-1969 Camaro.....1970-1981 Camaro
Axle tube flange to Axle tube flange.............54 1/4".............55 1/4"
Between centerlines of spring seats.............42 7/16"............45 3/8"
Axle shaft length......................................29 33/64"..........30 5/32"

[JMarsa]

Wait, he says the axle shafts or the entire unit is from a Camaro? The housing is obliviously from a coil spring car with the mounting tabs on the center section. 1st and 2nd gen Camaro's all had leaf springs. If you need new shafts, take them out and measure the length and spline.

--JMarsa

[64Chevelle]

double post

[64Chevelle]

Wait, he says the axle shafts or the entire unit is from a Camaro? The housing is obliviously from a coil spring car with the mounting tabs on the center section. 1st and 2nd gen Camaro's all had leaf springs. If you need new shafts, take them out and measure the length and spline.
--JMarsa

I'm starting to think that the housing was not an original 4-link setup. The mounting tabs for the UCA's doesn't seem to be from the factory as far as I can tell. The tab seems too large and a part of it extends outside the pumpkin housing. But I might as well be wrong, I don't know more about rear axles than what I can find on the internet.

[64Chevelle]

It is a 8.5", can't tell for sure about the camaro part. Can you read the castings numbers on the pumpkin?

Here is some more info:

.................................................. 1967-1969 Camaro.....1970-1981 Camaro
Axle tube flange to Axle tube flange.............54 1/4".............55 1/4"
Between centerlines of spring seats.............42 7/16"............45 3/8"
Axle shaft length......................................29 33/64"..........30 5/32"

Thanks lot, this was really helpful. It was difficult to get exact measurements since I only have a metric tape measure and the drums brakes are still mounted on it...

Axle tube flange-to-flange: ~140cm = ~55 1/8" (but it might be just a little more so, I'd say 55 1/4" is correct).

Axle shaft length: ~76.6cm = 55 5/32" (28 splines)

The gear ratio is 41/15 = 2.73:1

So, do I have a Camaro axle with modified mounts for the coilsprings + 4 link control arms? That's the most plausible explanation right now, unless there are some other 8.5" 10 bolt 4-link interchangable from another car that I'm not aware of.

[JMarsa]

Post a close up pic of the mounting tabs.

--JMarsa

[64Chevelle]

Mounting tab and shock mount with coarse welds...

https://static1.pt-content.com/images/pt/2009/01/28012009002-1.jpg

https://static1.pt-content.com/images/pt/2009/01/28012009-1.jpg

[64Chevelle]

Btw, found a good site with useful information:

http://www.chevellestuff.com/qd/generic_rear_axle_info.htm

Probably doesn't apply directly to me, buth still good info.

[Memphis]

Heres something to help you on finding out which 10 bolt it is for sure.
https://static1.pt-content.com/images/pt/2009/01/zmig3q-1.jpg

[MonzaRacer]

tabs welded on it looks like

[big gear head]

You are very brave if you use that rear end. It's a Camaro rear end that someone has modified. It is difficult to weld cast iron, and if it isn't done exactly right then it will not hold. I would take the posi out of it and scrap the housing, or use an after market suspension like a 3 link or truck arms that don't have to be connected to the center casting.

[64Chevelle]

You are very brave if you use that rear end. It's a Camaro rear end that someone has modified. It is difficult to weld cast iron, and if it isn't done exactly right then it will not hold. I would take the posi out of it and scrap the housing, or use an after market suspension like a 3 link or truck arms that don't have to be connected to the center casting.

Marcus at SC&C told me the same thing about the welding. I had no idea about this problem and have been driving with that axle for more than 10 years without problems.

An issue I have right now is that I've bought a LS1 rear brake setup and need to move the mounting tabs a bit inward to clear the parking brake setup. I've got a friend who is a good welder who can TIG weld it for me, will that hold or should another technique be used?

[big gear head]

Welding to the axle tubes is no big deal. It's the cast iron welds that are the problem. You don't know how they were welded and what they were welded with. I don't know what has kept them on there for this long.