So I have a vibration in my truck... Almost 100% sure that it is coming from the rear since I dont feel it in my steering wheel... I was hearing a rotational clicking at very low speeds (like leaving from a stop) and it disappears at higher speeds (I do understand why it disappears at higher speeds)... Once I get to the higher speeds (55-65 mph) its starts to vibrate... Once i let off on the throttle the vibration decreases... Im thinking drive shaft?? Anybody agree with my diagnosis??

 

driveshaft as well as u-joints have a pulsating vibration. It will be high then low consistently repeating itself.
If you are hearing a clicking, then chances are your u-joints are of culprit. The driveshaft itself doesn't make any noise as it's actually a stationary part attached to rotationg u-joints that do the moving, unless it's hitting something which i doubt? ( I understand the driveshaft spins, but it is stationary when compared to the u-joints that do all the moving)

I'd crawl under and check things out. Make sure your u-joints don;t have any play.

Another vibration could be from your differential. Hopefually that's not the case and that is tha last place I would look.

These both happened at the same time? Just trying to rule out the possibility of a bad cv axle even though you say it's coming from the rear.

 

Well explained as usual!! ^^^ x2!

 

when ya check them u joints make sure u are on level ground,chock front and back of wheels and put the tranny in nuetral.This will take all tourque off driveline.I have seen u joints bad and when the tranny in park there can be enough torque on the driveshaft that u cant move or feel it with your hands..MAKE sure all wheels are blocked good,i usually do it on grass as well so its harder to roll if it should.

 

Good point never thought about that. good job. nice heads up.

 

thanks for all the help/suggestions... Although I hope its not the rear differential, I do have 4.56's waiting to be installed when I enough time to put them in.. So I do have an excuse to crack the rear open..

 

i would almost be willing to bet that if u hear a clicking on takeoff its a u joint.Dry needle bearing crackle like crazy on takeoff and will vibrate at high speeds.Ive seen it way to may times from cars to 18 wheelers.

But it would be a good reason to swap that rear while u are under there