cletusvandamme

Hey, I decided to create a profile here to ask about my rear end in my 70 Chevelle. I cant find much information on it.

My major problem is that I believe I have bent axles. I put the car on a lift and both rear tires were wobbly.

Changed wheels, and still wobbled.


I took the drum off and pulled on the axles and there was some movement, in and out. Heard you cant have any movement with them.

I also noticed there was a bracket with 4 bolts holding in the axle.

I did some research and learned that this is a "bolt in axle" set up, not c clip.

Second, I couldnt find any numbers stamped on the tubes. I looked on top of the tubes, between the spring posts and the differential, but couldnt find any numbers.

All I can see is a big A cast on the diff, and a plastic breather tube on the passenger tube.

This topic was pretty helpful:

https://classicoldsmobile.com/forums...-end-mine.html

Looks just like the one oldzy posted, but I believe my cover is different.

My question is: am I right stating these are bolt in axles?

second, Since its an A-Body 10 bolt, the axles differ from non A bodies?

third, Where do I find axles? I cant find any like on summit, rock auto, ect.
I use 71-72 cutlass as my search car.

forth, how do I pull these axles out? With an axle puller?

Finally, do these axles look correct?

http://cgi.ebay.com/ws/eBayISAPI.dll...tchlink:top:en

thanks.

Fun71

Yes, they are bolt in axles. The axle shafts are removed from the housing by removing the 4 nuts on the flange, then slide the axle out of the tube. I have used a chain through the hole on the axle flange with the other end of the chain attached to a wheel, then use the mass of the wheel as a slide puller to bump the shaft out. Sometimes it takes a bit of force to pop the bearing and seal loose.

You should be able to get axle shafts from any of the major companies. Just call and ask about GM 8.5" 10 bolt rear bolt-in axle shafts.

Allan R

The GM 10 bolt 8.5" is a 28 spline axle. FWIW, you can also take them to a shop and have the axles straightened.

2blu442

I'd be more inclined to think the bearings pressed onto the axles are bad instead of bent axles. Once you get them pulled you can inspect everything and hopefully identify what's causing the wobble.

cletusvandamme

I was told this on another forum, that the bearings could be bad, not the axles. The run out isnt huge, but with wide tires I can see it. Both tires seem to have exact same wobble.


How can you tell if the axles are bent when looking at them? Will the be twisted at the spline area? or do I put a level on it?

thanks for the responses everyone.

cletusvandamme

would it be a major job to straighten axles? I mean would it cost more than new ones?

Allan R

Check the bearings first. They could be pressed on wrong. What kind of bearings are on your axles? Are they the conical ones that need a cup in the axle tube, or the square cut bearings that fit into the axle tube without a cup? If they are conical, they're not OEM and that could be your problem.

A good machine shop will be able to straighten them without too much effort - they have the presses and measuring gages. Cost is relative to your area. New axles can be as cheap as 100.00 each. OR you can get them from one of the guys on this site who part out these cars regularly. Where are you located?

Scott Winn (oldspackrat) is in indiana
Brian Trick (507OLDS) in Pennslyvania
Eric Jensen (jensenracing77) in Indiana
John McNeel (2blu442) in Oregon

All of these guys have the axles if you need replacements on a budget.

cletusvandamme

Location is CT.

I dont know what kind of bearings, Im waiting on a puller. Ill take pictures when I take it apart.
Im thinking it might be something other than the axles as well.
The wobble is almost exactly the same for both wheels. It seems odd that both axles would be bent and produce a mirrored type wobble from both wheels.
I know the rear has been beat on, previous owner did donuts, burnouts, and blew it up. He had to replace differential parts I heard. Still, its a good rearend from what I read, almost as tough as a 12 bolt.

TripDeuces

I'll sell you my 12 bolt and your problems will be solved.

RetroRanger

No need for a puller, like stated above attach something w mass to the axle a couple yanks and it's out, I chained a 3 foot 4x6 to mine and it came out easier than expected as it ended up on the floor

cletusvandamme

I used a puller, they came out real easy. One of the bearings was broken. The face or outer ring had a piece cracked off. Axles looked good, there was no visible damage to splines or twisting. I dropped them off at the machine shop to have them put on a lathe to see if they were bent.

The previous owner told me today that the rear was from an 82 Oldsmobile. I though older Olds were G bodies.

cletusvandamme

Anyway, I guess im buying new axles.

Came back from machine shop. Owner showed me on the lathe, passenger side is real bent, drivers side is not bent that bad. What kind of bearing are those?
Conical?
Heres some pictures:



DSCN6668_zps4df1432a.jpg

note the broken bearing:

DSCN6664_zpsd66ce238.jpg


DSCN6665_zpsb3ee79ef.jpg

Allan R

That's just nasty looking. Those are the square shoulder bearings GM installed in pretty much all the A bodies. Likely someone slammed the car into a curb sideways at higher speed to do that kind of damage. May have damaged your carrier too if you look carefully.

Count the axle splines. Reason I'd double check is you said the rear end is from an 82 Cutlass. If that's true, you're not running an 8.5 corporate rear end, it will likely be a 7.5" and the splines may be 31.

cletusvandamme

I counted splines, its 28 spline and 29.625 in long.

I believe they are this:

http://www.summitracing.com/parts/rnb-630-140/overview/

Its def a 10 bolt 8.5. Previous owner might have been mistaken.

Allan R

I noted that the axle application guide for that link specifies 1973 and newer.

Seriously though - check with one of the guys I mentioned above. They likely have the axles you need for a fraction of that cost.

Brian Trick works on differentials/gears for a living (507OLDS). So does Jim Mitchske (monzaz) - he runs JD Race & Associates

507OLDS

The factory bearing will allow endplay without distortion of the bearing.The new bearings will not.They need preload,to keep the cone in the cup.
The bearings are SET9,and the seals are 712146. If you really do need new axle shafts,you will need to order them directly from Moser or strange.The ones in the Summit catalog are not it.If the original axles really are bent,then I would take a look at the housing itself,to see if that is bent.

cletusvandamme

I better find some numbers off the rear end.

I looked where this picture says the numbers are, but cant find any.


http://www.pontiacpower.org/74axle.htm

Are the any numbers stamped anywhere else to help id?

Allan R

The axle code on a 72 is on passenger side, between the vent and the diff housing. It will be on the top side. Letters and numbers are cold stamped and may be hard to read, especially if you have a lot of surface rust on the axle tube.

If you want to know the gear ratio, it's really easy right now that you have the axles out. Take off the differential cover and check the ring gear. It will be stamped with the number of teeth on the ring and pinion. The stampings will be on the end of the ring, and you'll see them as you rotate it. Chances are good you likely have a 2.73 setup. That was common for 71/72 Cutlass.

Fun71

Here's the stamped code on my original '71 10 bolt. Note that the housing is nicely cleaned and painted. The code isn't as easy to see when there's a layer of rust and dirt.

Fun71

I bought a rear end back in the early 80s that had a factory bearing like that. Ran it for years with no issues. The rollers are retained by the internal cage and can't really go anywhere with just that small side section missing.

cletusvandamme

I am thinking of putting axles back in and saving up for new rear end. The machine shop said that the drivers side axle was almost perfect, while the passenger side was messed up bad; 40 off he said. He also showed me the wobble for the passenger side.

However, both wheels had a good wobble to them, so Im thinking something else must be wrong. If the drivers side axle was almost perfect, how come that wheel wobbled just as much as the passengers side?

Also, the best part is that I got an A body 8.5 real close too. My cousins got a 71 cutlass convertible, totally stock, unrestored.

Allan R

1. Did you ask how much to straighten the bad axle?
2. Both wheels had wobble? Have you considered that the wheels themselves might be bent?

You might be over-thinking this. Take the wheels to a balancing shop and ask them to test the wheels for true. If they're not true, you've solved half your mystery. ALWAYS look for the solutions from small to large. It costs less in the long run. I don't know why most folks automatically assume the worst when it may not be the case.

Based on the wheel truing, it still may be worth your while to keep the original differential and just get the one axle straightened or replaced.

cletusvandamme

I swapped the front wheel with the back one. Both had wobble. Front wheel is a skinny 4 inch cragar, and I could still see wobble.

I asked the machine shop if he could straighten, he said no, its an art form.

Allan R

So if the axle was nearly perfect, the hub is what's buggered up? Should be able to see that without having a wheel on. Try and see.

cletusvandamme

Ok I put the axles and brakes back together. The drivers side axle and flange looks real good. I mean I cant see any wobble without wheel on. There is some worn spot on the flange, where it was a 1000 off, but thats it.

The passenger side was real wobbly. Even without the wheel on, you could see it wobble from a mile away.

I dont think the housing is bent. I looked down the shafts and it looked good. No damage.

Also, I took the brakes off to get the axles off. I think I didnt have to do that. There are holes in the flange for an extended socket to get to the 4 nuts holding in the axle.

Anyway, I called Moser and they said I could ship the axles down there so they could make a perfect clone. Should I get 2 or do you think I could get away with ordering 1?

heres a pic of the rear.

DSCN6669_zps7a8e0bc2.jpg

Allan R

Maybe you should have opened up your differential and looked to see if there was any damage to the carrier or its bearings.

I still think getting in touch with:

Scott Winn (oldspackrat) in indiana
Brian Trick (507OLDS) in Pennslyvania
Eric Jensen (jensenracing77) in Indiana

could get you good replacement OEM axles on a budget.

cletusvandamme

Are set9 and A9 bearings the same?

507OLDS

Yes. The SET9 and A9 are the same bearing. Different manufacturers have the different numbers.

cletusvandamme

thanks, sent pm to you.