I have a 78 f150 4x4 and at 30 miles per hour it gets a vibration the only way to stop it to come to a stop I replaced the the 203 transfercase with a 205 . I was thinking the vibe was in the transfercase wrong ! . It has new radius arm , track bar bushings ANY IDEAS>
what do you mean exactly by bad vibration...there is a thing called "death wobble" the wheels start shaking real bad steering wheel wants to yank right out of your hand...that can be caused by onblonged trac bar bracket hole, ball joints, worn/loose steering linkage....as for drivetrain vibration my guess would be somewhere you have a bad u-joint....if its the death wobble check all your ball joints and everything..throw a set of dal stabilizers on (if you dont already have them)
If is is not the death wobble but a buzzing kind of vibration be sure the drive line still had the balance weight attatched. Also if you changed u-joints recently the must be lined up with each other at each end. i.e., yolk cap up at both ends. I experienced this myself. It tok me a year to figure out why the vibration was there.
