bent driveshaft?

Question

i noticed when my truck was on the lift and running that my drive shaft wobbles. could this be the reason why i get a werid vibration around 55mph? id say it wobbles an inch or so. What can i do about this.

i just replaced the u-joint not to long ago

and there is only one u-joint, the other end of the driveshaft goes into the transfer case

you know its probably more like half an inch

Answer 1

Are you sure there is only one u-joint? Unless I'm having a senior moment, there HAS to be one on each end of the driveshaft. If the shaft is bent, a machine shop can straighten or re-tube and balance the shaft.

Answer 2

Universal joints would most likely be the cause of driveshaft wobble. One that was bent by an inch would be so bad you would feel a constant vibration. The differential bearings could be worn out or the tranny shat, but the seals at those places would be leaking a good bit. Sometimes different rust patterns, dirt, and etc. could make the drive shaft appear bent. The vibration: could be caused by out of balance tires, bad tie rod ends, uneven tire pressure, any stabilizer bushing in the stearing components, vibration damper, fix-a-flat in a tire, univ joints, and so on

Answer 3

It would be more helpful to give the model and year of the vehicle in question. In any case, however, if the other end of the driveshaft goes into the transfer case there must be some means of flex inside the transfer case or the suspension couldn't work. Either this is worn and sloppy, or the shaft is bent. I would verify what the cause of the vibration is and fix it ASAP! Letting the vibration continue will place stresses and strains on other powertrain parts that they most likely were not designed to deal with, and can make them fail much more quickly. I hope this helps.

Answer 4

I would be very surprised to find it is a BENT driveshaft. Usually worn universal joints (at each end of the shaft) can cause the wobble you are descibing. Thank goodness they are a lot less expensive to replace than an entire shaft!

Answer 5

Yes, this could cause vibration, but there are many other possibilities. The vibration caused by driveshaft has higher frequency than the one from tires, it's easy to distinguish between them.

Answer 6

You can bend them by driving off-road and having the under body hit from beneath. I did the same when going over rough ground I went air borne and hit a mound of dirt underneath.

the vibration was worse when cornering. it was bent about as much as you say yours is. replace it.

Answer 7

it probably is the U-joints, that would make the shaft wobble.