problem with driveline?

alright whenever i drive low and go over about 40 miles an hour there is almost a grinding, vibrating sound whenever i let off the gas. if i'm giving it gas it doesn't make the noise its only when i let off. it doesnt do it at lower speeds and also if i'm at a higher ride height. its a 1994 gmc sierra ext cab sfbd on 17's it has a new carrier bearing and u joints. any help is appreciated :fon:

it sounds like your pinon angle is outa wack

yeah sounds like they are jacked

Edited: 3/28/2006 8:52:31 PM by SiLveRProJecT

i had the same prob with mine for a while...and my pinion angle was titled upwards alittle bit, ...so i adjusted my bars in my 4link and i was fine.

ANd i just noticed that you have a 2 peice shaft..so the noise is probably right under you in the extcab part...You think you could probably raise it up a little...i know you are limited on space with sfbd, just wondering if you have enough room

so you think that its coming from the carrier bearing? i think i could move it up maybe a half an inch. when its locked up the pinion angle looks good but when its lowered it looks like the axle is angled up a little, do you think that's the problem? thanks for the help

well it could be that too, however there are many things that could cause the vibration noise. Just seems in your case yours is caused when you change your angles by changing the height of your truck...here is a link that can explain better than i ever could...

http://www.bagginit.com/u_joint_page_1

that sounds similar if not the same as what mine did. When my carrier bearing started going out, it was like that, but as it got worse the vibration and grinding got to be constant. we found out the exhaust was heating up my bearing after a hanger broke off. the angle of the two piece can screw it up too.

its your pinion angle on the rear end.....