Had my 2001 explorer out on loan and it came back with an extreme shake at highway speeds. I was at a loss as to what was going on - sounded serious , front U joinits, Ball joints, tierod ends- who knows what. With a call to my friendly ford dealer they suggest that I wash out the inside of all the wheels, which happend to CAKED WITH GRAVEL ROAD MUD. That stuff was hardened on there like hobo **** to a railroad tie. Anyway problem solved with just a good hosing of all four wheels.

 

Sounds familiar.

I used to live on a gravel road growing up, and your right, that crap and get caked in there pretty good. Almost need a power washer to get it out.

 

Yeah, that always happens after going skiing. I get snow on the inside of the wheels and it makes the car shake until the snow melts out a bit.

 

It's the same off-roading with mud too.