I had some time last weekend to pull the tailshaft extension housing off the C4 automatic. I knew the bushing was bad as the drive shaft had some play on the transmission end. It really wasn't that big of a deal. About 2 1/2 hours for everything. The old bearing did show wear so it was about time. I also changed the seal (again). While I had the cross member out I modified the 'homemade' C4 adapter that the PO had made for the trans. This involved griding down what was left of the downward facing angle iron that was put there to 'strengthen' the mount. It wasn't really necessary as the plate portion was quite strong. It just hungdown and looked ugly. Anyway all back together and it appears it fixed a slight 'cluck' I was hearing when I shifted from reverse to drive.