watson

I am chasing a clunk under my 65 and I believe that I have found the source. I just finished a frame up on this car the clunk was not there before. The exhaust system was new before I took the car apart, so I reused what I had. The engine and exhaust manifolds are the original parts. My problem is with the center hanger under the transmission. I can't get the pipes to center in the holes through the frame. They sit too high (less than 7/8 inch clearance) and the pipes clunk when I hit bumps on the road. The bracket is the one that was on the car before, but I replaced the rubber mount cushion under the transmission. I have tried to align the pipes with all of the clamps and manifold bolts loose but they still want to be high in the frame holes. Is it possible that the rubber part of the trans mount could be too thick? If it was about 3/8 inch thinner, everything would be fine. It is obviously a reproduction part and I have not had much luck with that stuff. Has anyone had a similar problem?

Thanks,

Doc

66jack

Did you remove everything, the pipe from the exhaust manifold all the way out the back?

Double check this if you did what i asked...

Some times the part/portion of pipe that makes the bend around the spare tire tub will bump/rattle against the bolt/bracket that holds lid on/in place if you don't have this part far enough forward and rotated in the correct orientation to miss this part...

watson

Yes, that was actually where I started. I removed the spare tire tub just to be sure. I am now convinced that the problem is not at the back. I did put a spacer between the center hanger and the pipe and I got close to the 7/8 inch spacing. When I did that, the clunk went away. I am pretty sure that is where the problem is. Reading some old posts here, some folks talk about the difference between the hanger for 2 inch pipes vs. the 2 1/2 inch pipes. My car has 2 1/2 inch pipes but someone suggested using the 2 inch hanger to get more spacing. Before I do that, I want to be sure that the rubber cushion is not the issue.

Thanks,

Doc

66jack

"I want to be sure that the rubber cushion is not the issue."

Measure old vs new trans mount, are they different?...


:::EDIT:::

Then try your old one to see if that 'center's' the pipe...if you used all the old pipe stuff and only changed the mount...you moved something...

Mike Geary

On my '65 I just noticed that I have marks on the exhaust pipes, both sides, where the leaf spring has made contact. Not a lot a clearance there either.

Another source of clunks that we've talked about is floor sag allowing drive line contact. Recommended fix for this is hockey puck spacers on the cross member.

watson

Unfortunately I tossed the old cushion a while ago. The pipes have good clearance on the rear spring, I looked at the floor for sagging and it looks to be good. Thanks everyone I guess that I will just modify the hanger.

Doc