problem in halfshafts or lsd?
 

i was getting ready to replace my transmission mounts today, thinking that they were causing the clunking noise i hear (along with the car bucking) on deceleration, however when i got under the car i found out that they were fine.

so, i decided to jack up the rear of the car and check that out, and i was able to replicate the noise that i hear by moving teh driver's side wheel back and forth. how would i go about checking whether or not this problem is one with the halfshafts, or if it's a problem inside the differential?

the majority of these issues are the LSD-subframe mount being broken. It requires dropping the LSD to check. Also couldn't hurt to change the gear oil in the LSD while your at it, plus new copper crush washers. I like redline synthetic personally.

Wheel bearings normally cause a whine or grinding noise when they're going. You might also confirm no nuts/bolts are loose on the driveshaft & half-shafts.

what do you mean by move the D/S wheel back and forth?
front to back? in and out(side to side)?twisting it like you were checking for bearing play?

Sounds what i have, they told me my car was to low and binding the halfshafts. Dunno though

vaughnc- i replaced that mount a while back and installed a pinion snubber. it makes a different sort of clunk that it did when the mount was broken.


classicauto-i mean rotating them fowards and backwards, not twisting them to check the bearings.


andrewdruiz- yeah, i saw your thread when i was searching, and i thought about it for a while, but then i realized that i could make the noise with the car off the ground, which should eliminate ride height as a factor, i'd think. did you ever get yours figured out?

Come to think of it, i can also mimic this off the ground, does your noise sound almost like its coming from the hub area? I have yet to figure it out :( very annoying.

i'm having a hard time telling where the noise is coming from...when i move the wheel with my hands, it sounds as if it's coming from farther inwards (nearer to the lsd), but while i'm driving it sounds to be much farther outwards (in fact, when i first heard it, i though i'd forgotten to tighten the main subframe bolt on that side, because that's where it sounded like it was coming from).

have you checked your universal joints on the drive shaft?..after all,there is one that hooks the driveshaft to the differential..could be that is what you are hearing and not the LSD at all..guessin..

no, when i replicate the noise, i don't have to turn it far enough that the driveshaft would be disturbed at all.

what part of the halfshaft gets worn out, and how could i inspect it?

and also, how common is it for just one of the halfshafts to go bad? would i be better off replacing both of them at once with a known to be good pair?

doublecheck the torque on the LSD-subframe mount. I've under-torqued that lower nut before and it started clunking a bit. If you engage the e-brake and while idle pop the clutch very lightly (not enough to stall), you should just get a light ping/clank from the driveshaft. It's a loud clank, there you go.

the part of the half shaft that gets worn are the bearings........they are constant velocity type bearings located under the boots.....

I would watch it very carefully when you rotate it....if you can rotate the wheel and you see the axle turning, then hear a clunk - its may not be the half shaft.....it might be your diff.....

but if you turn the wheel and the clunk happens when the half shaft BEGINS to turn the its probably your half shaft........

BTW you said you turned the wheel like it turns normally to inspect this......but have you actually tried just checking your rear bearings - 8 out of 10 FC's Ive seen have shot rear bearings.....

well, that's no good. from what i can tell, the sound definitely comes after the half shaft turns...i turn it a bit then it's like it actually makes contact with something and clunks. how would i go about diagnosing a differential? from what the previous owner said to me, the lsd should only have about 25k on it now, that would kinda suck. any way to confirm whether or not its the lsd? (i'll check out the bearings)

vaughnc- i'll have to give that a shot tomorrow