We stumped our mechanics of 20+ years. We have replaced the following.
-Axles
-Upper lower control arms
-Front struts
-Tires with computized balance
-Computerized alignment
-Motor mounts
-also tried rotating tires
But we still shimmy and shake above 55MPH. It is a Mercury Villager 93
There was recently a long thread on a mysterious vibration in a Caravan that turned out to be rear brake drums that weren’t quite round (or were perhaps themselves unbalanced). Have a look and see if any of it sounds familiar.
How old are your tires?
Tires are one of the things we replaced, plus balance and alignment.
When did the shimmy start, and did anything on the vehicle change around that time (any work done)? In my case the shimmy ended up being caused by bad drums, but that’s pretty rare I’m sure.