When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission. Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.
A fairly common symptom. One major cause is a lack of sufficient grease (blue Ford grease) on the driveshaft slip joint (IIRC it's called the spline gear). A number of posts about this ... just search.
I have searched high and low and this is the first I have heard of this. I thought the d-shaft grease thing was just at take-off. Really good to know. I have 2 dutys that do this so I will try it!
I know this won't help but my 04 has been doing this for five years now, I literally went bald over trying to fix this and I still haven't gotten it figured out yet
put into tow haul mode and see if the shake speed moves.....if it does.....other possibilities is low transfluid pressure between 3rd and 4th usally cuased by filter needing to be changed and/or the incorrect tranny fluid. if that does not resolve....
if you are able to get pass the normal shake speed by putting it into tow haul mode....it will often move by 8 or 10 mph....and upon reaching the new shake speed you let off and hear metal clanking.....two posibilities....coast clutch has been know to crack at the base of the sleeve and/or ccrack in flex plate.
new tires all checked for balance
new U-joints (X3)
driveshaft balanced one week ago
All was done to alleviate the shake and it didnt work
at 40-45 mph the truck shakes from under the midsection. No shake in the steering wheel I cant figure this out.
Any suggestions?
Mines doing the same, no shaking in the steering but I can feel it through the pedals and floor. Now mine is a 2003 F350 reg cab 4x4. 135K. I climbed under it last week and found the tie rod was bad at the pitman arm. Changed it, drove a little better but vibration was still there. Mine is at 48 - 58 mph. I put it back in the air and found that the wheel hub bearings are shot, yours is an 08 but has the same mileage, maybe yours are bad also.