Questions on suspension parts

[infernosg]

^^^ All good points. I've considered the RTV trick, but hesitated due to the concerns you've expressed. I've also heard of people inserting objects between the stop washers and mounts (like ground down hockey pucks) but that would lead to the same issue.

Everything that's "colored" in that picture has been replaced by the Mazda Competition mounts, which are supposedly 40% stiffer than stock. The only "solid" mounts I have are the subframe-to-body mounts, which are delrin.

I checked for free-play in the drivetrain on Friday. Aside from discovering the left-rear wheel bearing is going, there was a little moving in the driveshaft at the u-joints, but it really is not that bad considering the car, and driveshaft, is 22 years-old. I'm now almost certain the ring and pinion backlash is off. There is a good amount of free-play in the rear wheels before I feel resistance. Time to go have a word with the shop that set the backlash...