# Clunk from rear of 1966 convertible GTO



## ragtopgoat (Sep 26, 2019)

This car has had a frame-off restoration and is very clean. The car is mostly stock. I believe it has Monroe air shocks in the rear, and what I believe are the original coil springs. It has an open diff. I've owned the car for a year, have put maybe 500 miles on it. Periodically when driving, when it rolls over modest bumps (like a raised man hole or expansion joint) I get a fairly loud clunk noise, that sounds like it is coming from under the rear seat. Doesn't do it all the time, as I've driven over a bump in the road that I expect to hear it and it doesn't happen. I have inspected the rear axle, drive shaft, springs, exhaust, near as I can tell everything looks good. The only thing that looks suspect to me, is the the exhaust tubing that loops up over the rear axle. As the tubing runs down behind the axle, it is parallel to the rear shocks. On the right side, there is about a 1/4" of clearance between the shock and tubing, on the left side it was actually touching the shock. I used a pry bar to try to bend some clearance in to it, and maybe opened it up an 1/8". The exhaust is hung from rubber straps and "floats" enough that I can bump it with my hands and make move enough to get some clunking from the contact with the rear shocks. But I can't be sure this is the source of the clunk. Is 1/4" of clearance between the shock and exhaust tubing too close? 

To test my theory, I am thinking about putting a rubber spacer or pad between the exhaust tubing and the rear shock, to see if that eliminates the problem, or at least alters the sound to confirm that's where it's coming from. Probably have to tie strap it in place as things will be moving when in motion and just the pressure or wedging a piece of rubber in there won't keep it in place. Would the exhaust be too hot this far back for a rubber spacer? Other thoughts or suggestions? I'm wondering if anyone has dealt with a similar clunk sound and can suggest other things I may be overlooking? 

Thanks in advance for your help!


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## GTOJUNIOR (Aug 7, 2011)

Sounds very possible to be the issue.
For a quick elimination test, a rubber pad/spacer is fine but do not leave it.


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## 67 ragtop (Jun 15, 2020)

you may need to bring it to a muffler shop to correct this 
the may need to heat the pipes and bend them out of the way
or tell you if that is the issue


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