u-joints?

hi, kind of a newb, but anyways, once in a while when i'm taking a right turn, i hear a knock in the rear under my bed, NOT extremely loud, but without the stereo on, loud enough to hear. it only seems to be coming from the right side, and only maybe once out of every...10 turns. Now, i have a 94 zr2 with the 4.3 vortec, i just bought it, and the 4 wheel is out on it, maybe the transfer case, maybe just the switch, but i doubt it matters on this. i asked my dad who's been working on cars since he was my age and he said it could be the u-joints getting worn. Any other suggestions as to what it could be? just trying to do a little preventive maintnance if need be.

hi, kind of a newb, but anyways, once in a while when i'm taking a right turn, i hear a knock in the rear under my bed, NOT extremely loud, but without the stereo on, loud enough to hear. it only seems to be coming from the right side, and only maybe once out of every...10 turns. Now, i have a 94 zr2 with the 4.3 vortec, i just bought it, and the 4 wheel is out on it, maybe the transfer case, maybe just the switch, but i doubt it matters on this. i asked my dad who's been working on cars since he was my age and he said it could be the u-joints getting worn. Any other suggestions as to what it could be? just trying to do a little preventive maintnance if need be.


I had a noise like that with my '94. Although it may not be the same noise, the first thing I would check is the rubber biscuits (mounts) at the ends of the transmission crossmember. If one is bad, replace both.

As an afterthought, during right and left turns (making a 90 degree turn, like at an intersection), I get a "clang" when the (automatic)transmission shifts from third down to second. This sounds like a small hammer lightly hitting a brake drum. I does it on upshifts from second to third as well, but not as loud and not every time. If this is what it is, then it is probably not going to damage anything - my truck has been doing it for over 150000 miles - the dealer could not find a problem).

I have a ZR2 with the same noise.My problem was the rear torsion bar was loose on one side and wore the mounting bracket on the rear end.I had to weld washers on it to fix the problem.

I have a ZR2 with the same noise.My problem was the rear sway bar was loose on one side and wore the mounting bracket on the rear end.I had to weld washers on it to fix the problem.

Never mind the first post.I meant sway bar not torsion.

well i kinda had the same problem i think if it makes noise around a turn and especially if it gets louder as u give it more gas than its probably the u joints that is on the front and if the 4 wheel drive is out than the only reason ta replace it is if you dont wanna listen ta it anymore but if its comin from under th bed than its probably the rear drivesaft u joints in which case u deffinitely wanna replace both of them


p.s. some other symptoms were as time went by it got louder than it changed from a loud knock to an increasing rumble under the truck if this happens replac them a.s.a.p. good luck