I have a 97 XCab Flareside . It has a shake like tire balance from the rear mostly . Sometimes it feels like it in the front also but very light. Mainly on smoother roads concrete type. Doesnt shake the steering wheel but does shake console and u feel it in the seat. Did this stock and lowered . Not tires have new mags @ tires no difference. Ckd axle for bent tires rebalanced ckd tilt on motor @ rear axle . Found notta Ford wants to hange parts to find it at my expense. Anybody have this problem NEED HELP

 

big slammy,
i have a 97 scab it sounds like the same concern i have when i tow my trailer. at about 38-55 the whole truck kind of virbrates? check your rear driveshaft slip yoke for end play. then check your u-joint on the same end of the shaft, even if you have the slightess movement replace the yoke and both u-joints, it worked for me...GOOD LUCK !