Jimmy Barnett

Have an 86 F150 w/ 302 engine and auto transmission. The truck vibrates and shudders when driving in the 35-45 mph range. Slower or faster than that and the truck is butter smooth. Problem seems to be related to ground speed and not engine speed. Has new, balanced tires. Problem present before and after new tires. Thoughts?

Thanks in advance for any advice. Jimmy

ilovefords31

Check the motor and transmission mounts and make sure none of them are broken or loose.

fefred

I also have 86 f150 4wd with same problem, new tires. problem was worse before i put the tires on, but the shake is still pretty violent around 40 mph, seems to be worse when decelerating. The front end appears to be tight and alignment is good, checked tranny and motor mounts, they seem to be good. my truck only has 21000 miles, it belonged to an older gent who passed away.

JayzDaddy

Run a google search of a ford death wobble and see if it sounds similar

Loner

It might help for others to help, is the truck 2wd or 4wd? I personally would be looking at the tie rod ends, and all bushings. If they are orginal they are going on 30 years old. Just some food for thought.