C1 Rear Strut Rod Bushings Part #: 3764839

[Ken K.]

I'm replacing the rear strut rod bushings on my '59. I pressed out the old ones. These where rubber with a steel insert. The four new bushings that I have are GM part number: 3764839. These have a steel outer tube then the rubber and then the steel insert. Do I have the correct bushings? Should I go ahead and press the new ones in? Any tricks? Thanks Ken

[Joe L.]

Re: C1 Rear Strut Rod Bushings Part #: 3764839

Ken-----

You have the correct bushings. The original style are vulcanized-in-place. The GM replacements have an outer steel shell.

You can now purchase reproduction bushings which are devoid of the outer steel shell in order to re-create original configuration (i.e. if someone like a judge inspects carefully the outer steel shell can be discerned). Would I use this style bushing? Never.

[Bert L.]

Re: C1 Rear Strut Rod Bushings Part #: 3764839

Sorry Joe, do you mean you wouldn't use the repro bushing?

Regards,
Bert '60 1335

[Joe L.]

Re: C1 Rear Strut Rod Bushings Part #: 3764839

Bert-----

Yes. The original bushings were vulcanized-in-place in the strut rods. This was done so that the bushing would be, effectively, bonded to the strut rod. There is not supposed to be any ability of the bushing to rotate on its circumference within the strut rod orifice.

For replacement bushings, it's not possible to vulcanize-in-place the bushings in a field service situation. So, the replacement bushings are vulcanized-in-place to an outer steel shell. Then, the outer steel shell is designed to be installed in the field as an interference fit in the strut rod orifice. This accomplishes the same thing as the original design, although a slight amount of resiliency is lost due to the thinner elastomer cross section.

The reproduction bushings without the outer steel shell have no mechanism to ensure that the bushing is bonded to the strut rod orifice. Therefore, the bushing can rotate within the orifice and that's not how the system is designed to function.

Will the reproduction bushings work ok? Yes, in most cases I'm sure they will. Would I use them just to preserve that minor nuance of originality? NEVER.