Body Mount Question
 

About to replace the body mounts, as I've always heard a "rumbling" coming from the rear, seemingly just outside and down from the rear interior baggage area. I suppose the Differential Cross Member/Hanger bushings could also be making the noise, but want to replace the Body Bushings anyway.
https://cimg7.ibsrv.net/gimg/www.cor...551ad80311.jpg
Do those shims look "normal" for a 45 year-old Vette?
https://cimg2.ibsrv.net/gimg/www.cor...2417608d2f.jpg
Right side shims appear in much better shape.
AAMOF, I'm surprised the rubber's condition looks as good as it does. Probably shows the difference of a car spending all it's life in a relatively dry climate and another that doesn't.

https://cimg0.ibsrv.net/gimg/www.cor...dc1f404c85.jpg

There's a little rust creepin' in there. I hope i caught it in time.

But my question again; Are shifting shims normal, like in the first photo?

Thanks.
Steve

https://cimg5.ibsrv.net/gimg/www.cor...9a7117f678.jpg
Rear passenger body mount. Welded corner on caged nut.
Your rear body bushings look very good for their age. Mine were crumbling off. I think you will find those bushing look much better on the inside which is protected from the elements. Your bushings look so good I don't think I would replace them. And since I have mine out right now I want to replace mine with poly mounts on the #1 and #4 mount while keeping rubber on the #2 and #3 mounts. You said you want to replace your mounts. All of them or just the rear mounts? If the body is lifted high enough I would weld up the corners of the capture nuts cage while you can access them. I have a pix of one but not a very good pic.

As for the cross member bushings failing - forget it. They are very well protected and very difficult to remove. I replaced mine but needed a shop to get them out and they even complained. And what cam out had nothing wrong with them. It kinda defies our imagination of a nearly 50 year old part can survive but you will be disappointed if do remove them.

Those shims probably not shifting but were installed that way.

After stripping my 70' to the bone to rebuild it and judging by "how things were done on the line" I'd bet the shims pictured have been that way sine day one, no harm.:flag:

Those mounts look pretty darn good.

Yep, and do not need to be replaced. The AIM shows the shims and how they were to be placed.
:thumbs:

Thanks much.
Steve

70K miles and 45 years in a SoCal climate later, I do feel fortunate. But that noise! :willy:

Thanks.
Steve

It does seem foolish huh. But I'm just trying to eliminate that possibility of causing the rumbling noise.
What else could it be? Wish I could accurately record it and let you folks diagnose.

Thanks.
Steve

The front differential mount ?
https://warptown.com/project-corvett...t-replacement/
https://cimg3.ibsrv.net/gimg/www.cor...270b5d16fb.jpg
Differential mount

Thanks. Will take a closer look at it.
I've eliminated the spare tire/carrier unit and exhaust routing as a possible noise source.
:shrug:

Steve

Diff mount is possible. Does it clunk when you put it in reverse?

Could also be trailing arm bushings. These cars invent new ways to make noises every day.

Steve

The differential has enough oil, right?

Wheel bearings can also make that kind of noise. Check for heating at each of your wheels.

I haven't checked the level lately, but I will now.
Thanks for the idea.

Steve