i just bought this truck its an 02 gmc sierra ext cab w/ the 5.3 no traction control. my question is when i get on it i feel a rotating vibration cant really tell where its coming from it not too bad but its there. any tips what to check.
my other question is its lowered 4/6 on 22's 265/40/22 it hasnt been tuned yet for the tire size so the speedo is off would that affect shift points? it feels like it get to OD too fast truck has 137k on it

 

You should start by checking pinion angles and u-joints. The 4/6 is almost certainly the cause for the vibration and may need some shimming to get back into spec.

 

Yea what he said start checking the u-joints shaft balance. What speeds are you seeing the vibration start at?

 

I'll most likly take it to the driveline shop and have it looked over. It will vibrate any time I gass it hard. I can part throttle up to 80 and it won't do it. Only wot

 

If you can post pics of the diff, leaf springs and drive shaft it may be obvious to the naked eye. The driveshaft shop cant hurt but if you have a pinion angle issue they may not be much help either.

 

The more you get on it, the more it throws your pinion angle out of whack. It needs to be readjusted for the new suspension geometry. Dropping the nose of the differential a degree or two should make a noticeable difference.

 

Do any of you know the right carrier bearing to order? I waslooking on rockauto and they offer several different sizes. I am not sure if you are supposed to be able to move the ds around in the carrier. The whole thing will move 1/8-1/4" all the way around

 

order from belltech, mcgaughys or something one of there carrier bearing kits.

http://www.stylintrucks.com/parts.as...tfamilyid=3323

 

I was planning on ordering that kit but I think the bushing&bearing is about shot. So I was going to order another from RA to compliment the alignment kit