OK, so I decided to refresh the rear shock mounts today. Installed new Febi-Bilstein lower RSMs and Dinan upper RSMs.
Taking everything out was a cinch. Wish it had been this easy to install the springs. All that had to come off was the top nut, lower shock nut, and the two camber arm shock mount torx bolts.
The Dinan Rear Shock Mounts are a great kit.
PN: D110-0008
Left to right: Lower mount, upper mount and center bearing, top cap. This kit uses a separate washer and lock nut rather than the combined upper mount/nut part of the OE mounts. The top cap is aluminum and nearly as thick as the upper mount. There is a ~6mm recessed cup cut into it for the bearing to seat in. Very nice engineering.
Use the 10mm version for non-externally adjustable dampers. It's based on the diameter of the rod.
Bottom:
Top:
Showing stacked:
The lower bushing goes inside the rubber dust cap, over the metal reinforcement cup. I inserted the OE rubber dust cap into the hole first, then carefully slotted the lower bushing. After doing that, I pressed the bearing up through the hole. It is a very tight fit. I almost couldn't do it with my hands, a bushing press (hex bolt with a washer and two nuts) would probably help a lot to pull it through the mounting hole rather than mutilating your fingers trying to do it manually. There might be a better way of doing it, but I did it step-wise like that to ensure the rubber dust cap wouldn't get trapped, folded, crushed or otherwise deformed as it is very thin. Even the rubbery lower bushing has a higher density than the OE parts. The upper bushing is much higher density, and the cap is aluminum. The mount fits together better and once assembled on the car there is zero wiggle.
Comparison shots:
Cleaned up the dampers while they were off the car. Just because. Also checked to make sure they weren't blown. Compression and rebound seem the same as they were when I initially installed them over a year ago. Wish I had a shock dyno!
Here's what the old lower shock mounts looked like. This is only 60k miles. If your rear end is starting to feel less than excellent, it's a worthwhile thing to look at.
Done!
Impressions:
Because I replaced my shredding lower shock mounts as well I can't comment on whether the change is due only to the Dinan RSMs, however, the change is staggering.
Rear ride quality is smooth again, bounce is tamed, wobble under WOT is gone, traction seems to be improved. Rear squat is slightly minimized (it wasn't bad to begin with), unbalanced feeling crossing road crowns is better, and some croaks and pops from the rear suspension have been quieted. The rear usually got super squirrel-y thanks to the open diff hitting a tight corner as well, the transfer is much better now and the rear end no longer flops as hard onto the outside wheel. This seems to be resulting in less inner wheel spin. We'll see, I need time to confirm that, as well as a mountain trip.