Car is a 66 coupe 289 with the C-4. I have never had any issues with the transmission until this spring. It has developed a loud ticking/metal on metal tapping sound coming from under the car. Its ONLY under moderate to heavy acceleration. This past winter i did a major overhaul of the engine compartment. Mostly cosmetic with a few new mechanical parts. The only parts changed anywhere near the transmission were New exhaust manifolds and pipes. As far as the transmission goes I drained it and installed a new pan and filter since the old was bent up and leaking. The new one is now leaking as well. Job well done. I can't say for sure if i drove it before the new pan or not but it has since developed this noise in the past few months. Thinking it was the U Joints, I replaced those last month and it has not made of difference. I would like to compile a list of possible suggestions i can run through the next time i try to pin point this down. The only possible issue i can think of with the transmission at the moment is that i noticed when i last pulled the drive shaft the yoke had a bit of movement in the tailpiece. I can't say that it is extreme as it hasn't caused the seal to start leaking yet.
