Are all rear axles not the same?

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Old Dec 26, 2021 | 11:26 AM
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Are all rear axles not the same?

I was looking at getting a set of these for my '72 Supreme, but my rear axle housing has no place to mount them. I know it's the factory original, so are some different than others?

Old Dec 26, 2021 | 06:23 PM
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Not that familiar with the '72 Supreme, but here is page 104 from the '72 PIM...



Old Dec 26, 2021 | 08:50 PM
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Originally Posted by 72455
I was looking at getting a set of these for my '72 Supreme, but my rear axle housing has no place to mount them. I know it's the factory original, so are some different than others?
No, they are all the same. Go and look at your axle again, the bump stops should be there.
Here’s a pic of my original 1971 rearend, which is exactly the same as your 1972 rear.





And this is my 1970 rear. As you can see, all GM rears of that era have the same bump stops.





And I have to ask, why are you looking to replace them? As seen in the above pictures, two different originals are still in good shape since they should never contact anything unless you are driving off-road on some gnarly terrain.

Last edited by Fun71; Dec 26, 2021 at 08:57 PM.
Old Dec 27, 2021 | 03:42 AM
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Originally Posted by Fun71
No, they are all the same. Go and look at your axle again, the bump stops should be there.
Here’s a pic of my original 1971 rearend, which is exactly the same as your 1972 rear.





And this is my 1970 rear. As you can see, all GM rears of that era have the same bump stops.





And I have to ask, why are you looking to replace them? As seen in the above pictures, two different originals are still in good shape since they should never contact anything unless you are driving off-road on some gnarly terrain.
Apparently a PO removed them, cuz they aren't there.
Old Dec 27, 2021 | 06:28 AM
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Pics?

didnt you have some kind of traction control setup on there before?
Old Dec 27, 2021 | 07:13 AM
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Originally Posted by RetroRanger
Pics?

didnt you have some kind of traction control setup on there before?
I'll post pics tomorrow. The mounts are there but the rubber stops are gone, and the same guy that took them off also upgraded to boxed LCAs and lowered the mounting position on the rear axle.
Old Dec 27, 2021 | 07:47 AM
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Originally Posted by 72455
..... but my rear axle housing has no place to mount them. I know it's the factory original, so are some different than others?
......The mounts are there but the rubber stops are gone
I'm having trouble following all this, anyone else?
Old Dec 27, 2021 | 08:03 AM
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Originally Posted by tnswt
I'm having trouble following all this, anyone else?
At first I thought there were no mounts, but I double checked this morning and turns out just the rubber stops are missing.
Old Dec 27, 2021 | 08:55 AM
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Originally Posted by 72455
At first I thought there were no mounts, but I double checked this morning and turns out just the rubber stops are missing.
Good, I thought I missed something.

If originality is an issue I'd look for good, useable OEM rubbers because I found the repops are no where close to factory issue ones.
Old Dec 27, 2021 | 09:09 AM
  #10  
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Originally Posted by tnswt
Good, I thought I missed something.

If originality is an issue I'd look for good, useable OEM rubbers because I found the repops are no where close to factory issue ones.
Well..I'm about to find out. I ordered a set from ILT.
Old Dec 27, 2021 | 09:36 AM
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Iirc theres only one spot to mount the lcas, you might have an aftermarket traction control product on there
Old Dec 27, 2021 | 09:45 AM
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Originally Posted by RetroRanger
Iirc theres only one spot to mount the lcas, you might have an aftermarket traction control product on there
Yup..this is the setup...

Old Dec 28, 2021 | 05:05 AM
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Looks like in a previous life your Cutlass was a drag car? I guess if you want to be original you'll have to change those lower control arms back?? This is interesting, I've been following.
Old Dec 28, 2021 | 07:30 AM
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Those are the "Southside Machine" style lowers, marketed now by Lakewood and possibly others. They work very well at the drag strip on our A-body cars.
Old Dec 28, 2021 | 08:39 AM
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Originally Posted by Greg Rogers
Looks like in a previous life your Cutlass was a drag car? I guess if you want to be original you'll have to change those lower control arms back?? This is interesting, I've been following.
Nope..won't be changing them out, but I don't like parts to be missing...that's why I'm getting the bump stops.
Old Dec 28, 2021 | 08:43 AM
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Originally Posted by 67OAI
Those are the "Southside Machine" style lowers, marketed now by Lakewood and possibly others. They work very well at the drag strip on our A-body cars.
That would explain why she hooks up so good off the line...hardly any wheel spin. Not that I've taken it to the track mind you, but I've done more than a few red light pulls off the line😀
Old Dec 29, 2021 | 04:49 PM
  #17  
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Originally Posted by tnswt
Good, I thought I missed something.

If originality is an issue I'd look for good, useable OEM rubbers because I found the repops are no where close to factory issue ones.
And so you were right...here's a couple of "side by side"pics with OEM on the left and repops on the right...notice the ribs and the difference of thickness on the 'barbs"...




Old Dec 29, 2021 | 08:21 PM
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I'd be more concerned with the LxWxH comparison; as long as the barb can maintain a grip in the slot you are ok. It is the overall size that i had problems with when I ordered several years ago.
Old Jan 1, 2022 | 01:04 PM
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Is there a trick to putting these in? I just tried for 1/2 hour on one side and no joy. Also, do I really need them?
Old Jan 1, 2022 | 01:37 PM
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Did you try lubing them up with liquid dish soap ?
Old Jan 1, 2022 | 01:47 PM
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Originally Posted by 72455
Is there a trick to putting these in? I just tried for 1/2 hour on one side and no joy. Also, do I really need them?
I didn't say anything earlier about the pain of installation as you seemed very intent on having these. As said above, you gotta lube them, then force the rubber tab through the slot in the metal. It may be easier to try pulling them through as that will distort the rubber in the "right" direction so it's thinner while trying to go into the slot, as opposed to pushing the rubber which makes it bunch up and become fatter. Or maybe start on one end and use a tool to push the rubber flap (the part that holds the insert into the slot) through the slot, then work along the length pushing the rest of the rubber flap through. Doing this while the rubber is warm may make it easier that if the rubber is cold (and hard).

As for do you really need them, I think probably not unless you expect the suspension to bottom out (off-roading and the like).

Last edited by Fun71; Jan 1, 2022 at 01:49 PM.
Old Jan 1, 2022 | 02:31 PM
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Upon further investigation, I think I see now why they were removed...it seems the brackets for the boxed control arms preclude installation.


Old Jan 1, 2022 | 02:40 PM
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My suggestion would be:

(1) Begin with very warm rubber (heat in oven preferably as opposed to a heat gun);
(2) Slide/Pop in one side of the rubber tab(s) (as opposed to both sides simultaneously) employing a screwdriver (like you might a shoehorn) - tugging/forcing the one side in & as far as possible towards the outboard side as it will go; and,
(3) Employing a screwdriver or similar device as a "shoehorn", or as a "pinch" - force the opposite (remaining rubber tab side) into the slot with force.
Old Jan 1, 2022 | 02:42 PM
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Originally Posted by 72455
Upon further investigation, I think I see now why they were removed...it seems the brackets for the boxed control arms preclude installation.
Hmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmm...... .................................................. .................................................. .........................
Old Jan 1, 2022 | 02:48 PM
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Originally Posted by Vintage Chief
Hmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmm...... .................................................. .................................................. .........................
???
Old Jan 1, 2022 | 02:53 PM
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Originally Posted by 72455
???
I'm trying to understand why you put in the effort of attempting to install them if in fact you can't because evidently the brackets for the boxed control arms preclude installation.
Old Jan 1, 2022 | 03:11 PM
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Originally Posted by Vintage Chief
I'm trying to understand why you put in the effort of attempting to install them if in fact you can't because evidently the brackets for the boxed control arms preclude installation.
That was my point Norm...lol.
Old Jan 1, 2022 | 03:13 PM
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Originally Posted by Vintage Chief
I'm trying to understand why you put in the effort of attempting to install them if in fact you can't because evidently the brackets for the boxed control arms preclude installation.
That was my point Norm...lol. (See my post #22 above)
Old Jan 1, 2022 | 03:13 PM
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It might be time to move onto something more fun like the repositioning and correct operating functionality of your combination valve.
Old Jan 1, 2022 | 03:15 PM
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Originally Posted by Vintage Chief
It might be time to move onto something more fun like the repositioning and correct operating functionality of your combination valve.
Oh trust me, it's on my list😀...and I've already moved past the rear bump stops 😁

Old Jan 1, 2022 | 03:15 PM
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Originally Posted by 72455
That was my point Norm...lol. (See my post #22 above)
I know.
Old Jan 1, 2022 | 03:20 PM
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Repositioning that combination valve is not that big of a deal. If it's not functioning correctly, you need to address this. Just get your head around it. I'd buy a new combination valve, buy some new brake line tubing, buy the combination valve kit to mount the combination valve under the master cylinder (easiest most likely), adapters of the correct size and a new brake line bender tool. You could mount the new combination valve anywhere - that's your call. I certainly wouldn't spend time on what is stock and not stock especially in terms of location(s). Let's face it, many things about your car are not stock; but fix that combination valve buddy. You realize that is a safety issue correct?
Old Jan 1, 2022 | 03:27 PM
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Originally Posted by Vintage Chief
Repositioning that combination valve is not that big of a deal. If it's not functioning correctly, you need to address this. Just get your head around it. I'd buy a new combination valve, buy some new brake line tubing, buy the combination valve kit to mount the combination valve under the master cylinder (easiest most likely), adapters of the correct size and a new brake line bender tool. You could mount the new combination valve anywhere - that's your call. I certainly wouldn't spend time on what is stock and not stock especially in terms of location(s). Let's face it, many things about your car are not stock; but fix that combination valve buddy. You realize that is a safety issue correct?
Seems we've digressed off topic (again)...lol.
Old Jan 1, 2022 | 06:31 PM
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There is a specific lube used at the factory to install all rubber bumpers like these. I have a tube at home, but am on snow duty at work at the moment, so can't tell you any details. Stuff is amazing! If no one has posted it by the time I get home, I'll do so.
Old Jan 2, 2022 | 11:54 AM
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I decided to go ahead with the installation...


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