That said, Stevharr had a ticking sound in the engine. Was about to pull the bottom end apart when we worked out it was the air conditioner compressor. Bearing was stuffed. We just swapped out the compressor.

I know you think it's coming from the rear but you really need to get a second opinion from someone standing outside the car. I thought my transmission output shaft bearing had gone so rebuilt it, only to discover it was my diff (hence the rebuild). It could be your valves are out of adjustment from what you've told us.