# Size of the rear upper trailing arm bushing ??



## cij911 (Oct 25, 2017)

I purchased the Spohn del-sphere rear trailing arms and the rear upper does not fit on the the pumpkin / diff side. It appears the opening is much smaller than the supplied bushing, yet Spohn claims they are all the same from 64 - like 80 something (can't remember). Is this possible or is it possible the BOP rear's were unique and Spohn is unaware ? Or is it possible that I have a different rear end hahah ?

Ideas ?


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## PontiacJim (Dec 29, 2012)

cij911 said:


> I purchased the Spohn del-sphere rear trailing arms and the rear upper does not fit on the the pumpkin / diff side. It appears the opening is much smaller than the supplied bushing, yet Spohn claims they are all the same from 64 - like 80 something (can't remember). Is this possible or is it possible the BOP rear's were unique and Spohn is unaware ? Or is it possible that I have a different rear end hahah ?
> 
> Ideas ?



As I recall, 1964 is different and smaller than 1965 and up, so possible you have a 1964 rear axle.

Strange how Spohn would claim they are all the same when they have a separate bushing for "1964" only and a different one for 1965 and up on their own website. Must have been talking to a representative in India. Check this out, then give them a butt chewing and get your money back: https://www.spohn.net/shop/1964-196...e-1964-GM-A-Body-Chevelle-Malibu-GTO-etc.html


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## cij911 (Oct 25, 2017)

PontiacJim said:


> As I recall, 1964 is different and smaller than 1965 and up, so possible you have a 1964 rear axle.
> 
> Strange how Spohn would claim they are all the same when they have a separate bushing for "1964" only and a different one for 1965 and up on their own website. Must have been talking to a representative in India. Check this out, then give them a butt chewing and get your money back: https://www.spohn.net/shop/1964-196...e-1964-GM-A-Body-Chevelle-Malibu-GTO-etc.html


Thanks Jim!

If it is a 64 rear end, that begs another question - why ??? Amazing how you think you have everything identified on a car, only to find surprises....I guess I should open the diff and see what is inside....


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## cij911 (Oct 25, 2017)

64 rear bushing is ~1.4" diameter.....unfortunately I was not able to find a del-sphere or heim joint so I went with the standard rubber bushing. I will continue looking for a heim joint solution.


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## PontiacJim (Dec 29, 2012)

cij911 said:


> 64 rear bushing is ~1.4" diameter.....unfortunately I was not able to find a del-sphere or heim joint so I went with the standard rubber bushing. I will continue looking for a heim joint solution.


Your car may be factory correct with the '64 rear axle depending on date build.

What you are showing in your photo looks like a solid bushing with a pivoting center like a Heim joint, am I correct?

I would not use a solid bushing. The rubber bushing is what I used because I want a means to absorb some of the acceleration/road shock placed on the rear axle. If you go solid, the forces will find the next weakest point to stress and something could crack, break loose, or you may find that your attachment bolt holes at the crossmember may elongate from the acceleration and deceleration cycles.

I used the UMI adjustable upper control arms with the Roto-Joints ends. I am using a Ford 9" and custom suspension set-up, so I had to modify these and actually have them reversed for my application - rubber bushing is now on the frame side brace attachment and Roto-Joint at the rear axle. 1968-1972 A-Body Adjustable Upper Control Arms- w/ Roto-Joint [4037] - $259.99 : UMI Performance, Inc. Of course Spohn has the Del-Sphere joints as well. https://www.spohn.net/shop/1964-196...-with-Del-Sphere-Pivot-Joints-Adjustable.html

You would also want to add the upper & lower control arm braces if your car does not already have them. This will make the crossmember that your upper control arms attach to more rigid and flex less thus preventing any fatigue or stress cracking. I used the UMI brace on my '68. It is adjustable for an easier fit.


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## cij911 (Oct 25, 2017)

Yes Jim I had to go with a rubber rear upper bushing on the pumpkin / differential housing. All the other bushings on the rear are Del-Sphere from Spohn.

I replaced the front end and took the car out for the first time in 1 1/2 weeks and it is a night a day difference.


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