cire96

My 96 LT4 has developed a metallic snapping noise that appears to be centered in the drivers side rear hub where the U joint or axle bearing is located. It occurs whenever you take the slack out of the driveline - going frontwards or back.

It's loud enough to hear from inside the car. From the outside it's more noticeable. It makes no noise once the slack is taken out and if you ease away, there's none at all.

I removed the wheel and used the foot brake to hold the axle still and could make the snapping by going from first to reverse and partially engaging the clutch. Doing it that way (with someone else actuating it), I still wasn't able to specifically locate the source of the noise. I felt the outer U joint as it was being loaded / unloaded but it doesn't appear to have any movement when the noise happens. Likewise the inner one shows no movement that can be seen or felt either.
Any ideas would be appreciated. I autocross and this looks like exactly the kind on noise that'll get expensive if left untreated. Cire 96 :confused:

Robey5

No body really has been able to tell me exactly what this sound is. I have had this noise since I bought the car in 99. The sound is rather annoying, and it is even more annoying that no one really can say what this noise is.

Backing off of the soap box, I believe that it is your half shaft U-joints. I have mine in my garage, on my to-do list to have replaced. I am waiting till the end of the season.

96GS#007

If it's not a u-joint, then the splined axle yoke (spindle) is moving fore/aft inside the wheel bearing. The fix is to R&R both the yoke and the wheel bearing. Sometimes, tightening the spindle nut will temporarily "fix" the problem but it usually comes back after several hundred miles.

DarkHalo

I just went thru this on my '91 and it was the rear axle u-joints. I replaced them myself on a weekend. Our very own Scorp made a fantastic step by step "How To" page about it.

http://personal.tmlp.com/scorp/vette...nts/index.html

SPD DMN

Another vote for the u-joint here.

AGENT 86

If you can't rock the tire at 12 and 6 oclock and you can't see physical movement in the u- joint caps, you might be getting the noise from worn and dry splines in the shaft bearing assembly. You could pull the half shafts and check the u-joints and lf OK lube the splines and retorque the axle nut.This might just cure the problem. Good Luck !! :cheers:

NavyVet

A bit of anti-seize compound on the stub axle splines has cured this for others.

blk95

try that first,

cire96

Thanks to all for the input. I'll dig into it and let you know what cures it! Cire96 :smash:

cire96

NavyVet:
Can I simply loosen the nut to gain access to the spine in order to try the ani sieze approach, or do I have to pull the half shaft first? Likewise, to replace the bearing, do I have to pull the half shaft as well?
Cire96

vmi_vette

I just replaced a half-shaft u-joint and the left side rear wheel bearing and hub assembly. My snapping noise happened to be the bearing/hub assembly. The bearing and little spacer between the spindle bearing seat and the bearing got chewed to hell. Replaced both and cleaned up the spindle splines. No more noise. I did put a little anti-seize on the splines, but that should be the only place.

If you have to pull the bearing/hub assembly, it is much easier with the half-shaft removed. This also allows you to pull the spindle out for cleaning.

Good luck.

Atok

:iagree: Two weeks ago I fixed this problem with my '95. The symptoms are exactly as you described them. I thought it was the U-joints at first so I pulled the axle only to find them in perfect condition. Then I removed the hub assembly and found the axle nut quite loose (maybe 100 ft-lbs). The bearing was tight so I figured it must be the spline/loose axle nut. I cleaned everything up, checked the washer between the hub and axle spline (it was in good shape), coated everything with anti-seize compound, then put it all together and torqued the axle nut to the GM spec (164 ft-lbs). The noise was gone and hasn't returned in 600 miles.

If it was the U-joint more than likely it would make noise under load or when the suspension moves up and down under load.


:cheers:

NavyVet

:iagree: Atok covered it. Remember to torque the axle nut to 164 and don't get the anti-seize on th threads for the nut (splines only) or you'll get an incorrect torque reading. This worked for me. Good luck - it's been 104 in my garage every night after work lately, so if it was mine and the bearings were good, I'd put it off until October :D

cire96

Update:Snapping Problem fixed - at least for now. I retorqued the axle nut and viola...noise gone! ran an autox yesterday, drove 100+ miles and all is well so far. BTW, I learned that for standard shifts, the correct torque is 200 lbs. The earlier referenced 164 lbs. is for automatics. Thanks to all.
Cire96. :cheers:

Gar

Dad worked for Chrysler in the engine room for many years and he always says 'try the easiest thing first'. Retorquing the axel nut may have saved ya some major bucks later on! :cheers:

cire96

:cheers: Here's to your dad and mine. In my case, the mantra was, "If it isn't broke, don't fix it".
Cire96