C4S993

Yes, the boat shaped washer is useless and because it is serrated it pops off threads and becomes out-of-round. Instead, I did like Detroit does; spring loaded washer works perfect.

C4S993

New problem has be stuck ! I cannot budge the perch nor the middle of three collars. I will remove and drop off at local shop to see of they can coax the perch lose with some heat. If that fails I will call factory to see if Belstein can supply just the strut+collars w/o springs. Springs are marked 11/2007.

ToSi

The boat shaped upper washer has a purpose - it bottoms against the rubber humps protruding from the top of the mount, presumably during large rebound 'events'. Look closely, it's asymmetrical to account for shock movement & rearward recession of the subframe.

Here's the correct orientation:

C4S993

Quote: "presumably during large rebound 'events'" on nonajustable Monroes ? Than yes, I would buy that, but on adjustable PSS10 (rear) I am sticking with the spring loaded washer. Thanks ToSi for that info though. Anyway, in my situation both L+R boat-shaped washers lifted off the shock's 12mm threads and just spun around and thus lost their relative position to the large bushing double humps. Curious though why the PSS10 system (rear) does away with the slopped arrangment that accounts for the slopped body mounting surface ? The PSS10 system (rear) bolts flat against the slopped mounting surface with no accounting for the rear slopped body work.