Basically, my exhaust pipe is bonking against the "cross member" of the "frame" right near the catalytic converter. It first did it with the engine under heavy load, when I took my foot off the gas going over a mountain pass. Now it does it any time you take your foot off at any speed over maybe 50 mph. When the tranny is in reverse, the engine of course torques over a little and it (the exhaust) then is pushed constantly against the cross member and there's a nasty vibration that you can feel.
One of the motor mounts, and the tranny mount are new and just checked out as "good". The exhaust hangers all seem to be there. I replaced the header pipe a few months ago and at that time had to mess with the "L" bracket up near the oil pan/header pipe area that bolts the header to the engine block. However, everything has been fine for months since then. So I guess the question is, what changed??
I have gotten under there and pried things around. I thought I could just loosen the bolts on the "L" bracket, pry the exhaust pipe down, and re-tighted the bolts to get more clearance, but the engine, tranny, exhaust, and driveline are all "sprung" together and it does not appear that that will work.
Anyway... any ideas?
-jeff