I have a 2006 f150 5.4l 4x4 supercrew. i had my wife's car on a tow dolly this weekend and at speeds between 60 mph and 75mph the hole truck shakes. It fills like the drive shaft or pinion angle . I did check the u joints and they fill good. it does not do this empty. thanks for any help.

 

Tow it with another truck to see if the problem is with your truck or the dolly or car.

 

i used my friends 2000 f150 and it did not shake at that speed. thanks for the reply

 

Using a tow dolly at 75 mph???

It's probably 'torque converter shudder' if you were feeling it while accelerating..

When was the last time the trans fluid was changed?

Mitch

 

If it's a U-haul dolly, the speed limit is 55........

 

I'm not gonna beat you up on the speeding while towing thing, but I would definitely get that transmission checked out soon. Sounds like TC shudder to me. As Mitch asked, when was the last time the tranny was serviced?

 

I just completed the trans service ( 16qt of ford sp thru a bg flush machine). and still doing it .I am going to try the pinion angle.THANKS for all the support