Hi all, I am a new member have owned about 4 ford trks in time. Presently
have a 1994 f150 XLT 4.9 with 107,000 miles automatic overdrive.
I had some ole tires that were worn out and out of balance and seemed
to bounce worse as I turned a curve at about 40 MPH.
Last week I had a new set of Goodyear Wranglers 15 x P235 2 ply put
on trk. On highway between 30 and 40 MPH I get a bump which seems
to be coming from rear. Trk was re-aligned and runs straight. No broken
springs or shocks. Took back to dealer, they drove it and re balanced
tires, then drove again with no change. They told me I may have a drive
line problem. Driveshaft is tight including u joints and no oil leaks in rear.
Transmission man said if driveshaft was out of balance it would show at
various speeds. I have no noise associated with this problem of any kind.
Trk is stock 2wd. Could it possibly be axle bearings? Trk has never been
wrecked and rims seem to be ok. I am an old hotrodder but never experienced this before. Just wondering if anyone out there ever encountered this problem, and what did you do. Any suggestions would
be appreciated.. Sorry for long letter, good to be a part of your club.

 

LWB or SWB? If LWB is it a 1 piece driveshaft or two? If a two piece driveshaft check into changing the midship bearing. Also check for dents / bent driveshaft. Missing weights.

 

Been under trk it is one piece drive shaft and nothing loose. All weights
are accounted for. Trk is LWB