Update: $30 and repaired! Spring Nuts
The rear suspenion on the '91 300E is now back to the proper ride height. I have been chasing this problem ever since I replaced the rear springs due to sagging.
I was having the A/C recharged and mentioned it to Bud @ Cupertino Service, in N. CA. He said they have been using spring nuts. He showed me an 86 SL they just did. Not very elegant, kind of a JCWhitney solution, but they work great.
BTW a spring nut is a squarish, slightly larger than a lug nut sized item that is inserted in between the coils of a coil spring and then twisted to lock in place. It takes a great deal of effort and a hefty 1/2" long breaker bar to twist it. They come in different sizes, they used the smaller size and the rear is perfect.
I'll update this thread, but so far I am really pleased.
'03 E320 Wagon-Sold
'95 E320 Wagon-Went to Ex
'93 190E 2.6-Wrecked
'91 300E-Went to Ex
'65 911 Coupe (#302580)