chrismunn

let me give you a short background.

about 3 months ago i had a u joint replaced and had my drive shafts balanced.

a couple of days ago i did a burnout from a dead stop, while turning to the left and my back end started to bounce really hard. the truck turned about 45*-60* degrees while bouncing, and now im getting some pretty bad vibrations coming from the mid to rear end when i get to about 35+ mph. the vibrations feel very similar to the way it felt before i had my shafts balanced 3 months ago.

my question is in regard to the vibrations.

is it possible to throw off the balance of the drive shaft by doing what i did? also, is there any way i would be able to tell if i needed to have them re-balanced without bringing them to a shop?

this question is in regard to the rear differential.

is it possible that the vibrations are coming from the rear differential and not the drive shaft?

one thing i noticed today while i was snooping around is that there is 1/16" of latteral play in my rear wheel hub. is that normal or could it possibly be whats causing my vibrations? this video will illustrate the movement in the hub.

johndb

You may have thrown a wheel weight doing your burn out, check that first, maybe rotating your wheels front to back and check if the vibration moves to the front, then you can eliminate your wheels as the source. You may also have blown a wheel bearing, how do your wheels spin when jacked up, also try rocking them up and down and side to side.As for the latteral play I'm not to sure,sorry.

shawnvw

That play is normal and won't cause your vibrations.

I LOVE that fact that you recorded the play. I wish more people would do stuff like that. It would certainly help us in helping them.

I would try as johndb said and rotate the wheels to see if the vibrations goes to the front

chrismunn

well i rotated the tires today and put the rear tires up front and it didnt do anything.

i hope its not my wheel bearing, last time i replaced one of those i forgot to put the e-brake assembally back together before i pressed the bearing into the hub and i ruined the bearing while trying to take it back out!

how many moving parts are there behind the transmission?

there is the 2 drive shafts, the differential, the 2 shaftes that go from the rear diff to the wheels, and then the bearings right???

im assuming that if it was the rear diff then something would have siezed by now so ill count that option out. that leaves the 4 shafts and the 2 bearings...

EvansBlue

I'm guessing that you may have broken something in the differential.

Otherwise, you may have broken an engine mount or a trans mount that is seperated or broken. I did a rolling burnout in my Blazer about 2 years ago and broke the engine mount. The way to test for this is to have someone stand to the side, hood open, and watch the engine. Then you 'powerbrake' it without spinning the tires, if he reports that the engine jumped, then thats likely the cause.

chrismunn

huh, i would have figured that if something had broken inside the differential that it would have seized up or at least would sound horrible!

ill check the mounts to see if there's something broken?

so, how do i power brake exactly???