Sharp clicking from passenger rear half shaft area.

[Ls7/Ls9 Test Engineer]

Hey all, it’s been a while.

I just started driving my 94’ Z last week after sitting for a while and I’m starting to notice a sharp clicking sound when I slowly let out the clutch and the car begins to move...
I’ve checked the lugs and cannot seem to find any play in the half shafts

There is no vibration at any speed and the noise is only present during stop start in either direction..

Are there any known issues that could be causing this noise?

Thanks for any assistance...

[Flyman 27]

Sounds like a universal joint to me.

[Ls7/Ls9 Test Engineer]

I forgot to mention that the car has 35k miles.

I also thought the same thing, but everything seems to be very tight and in good shape.
The sound is very sharp and crisp, almost like a “snapping” sound...

[DRM500RUBYZR-1]

See if the sound changes with:
1 -mild application of brake pedal before moving
2- partial application of Safety Brake before moving


While certainly not out of the question, 35 k miles seems low for drivetrain issues, low but not impossible.
Service or safety brake provide lots of opportunity for sound on initial movement, so let's rule that out.
Let us know what you find.
Marty

[lfalzarano]

I’m with Marty on the suspicion of the rear breaks, since it occurs upon braking and then take off.


Sent from my iPhone using ZR-1 Net Registry

[billschroeder5842]

Marty and Lou are headed down the right path.

I had a similar situation when I first got my 91 from the original owner. Inspection showed that the rear calipers were not seated correctly (!) and the pin holes were worn "oblong." and was "floating" as the brakes were applied. I put on a new set of calipers and the noise went away.

[Hib Halverson]

Can you be a little more specific on when the noise comes?

You say "stop-start" in either direction. Do you hear the noise only when accelerating from at rest, either in forward or revers gears but NOT under braking? Or do you hear it on acceleration, on braking and either forward or backward?

Since this seems to occur at slow speeds, have an assistant with good hearing, squat down and listen as you accelerate to see if the noise is coming from under the car behind the front wheels or from the rear of the car.

Also, is the noise just a single click each time or is it a chattering noise?

Finally, does the noise occur only after clutch release or does it happen during clutch release?

[Marc Haibeck]

Is it a crunch sound that is most likely to occur when going from reverse to forward?

A common cause is loose rear spindles in the rear wheel bearings. The splines are a loose fit. The clamping action from the nut keeps the spindle from rocking in the bearing splines. It's easy to eliminate this possibility. Just remove the rear tires and tighten the nuts. The torque specification is 164 lb. ft. I like to tighten them about 10% tighter to 180 lb. ft.

[Ls7/Ls9 Test Engineer]

Good morning guys.

So to be more specific, the noise happens when the car moves either forward and backward from a full stop. The noise is more prevalent when the car/brakes are cold.
I tried the suggestion of engaging the parking brake and then gently trying to move for & aft. The noise did not occur at. The issue appears to happen only when the rotor moves, which has now moved my focus to the caliper and pads.

I’ll keep everyone posted on the progress in locating the issue, but it may be a while as I don’t use the car very often.

Thanks again for all of the suggestions and responses.

[RichS]

I've seen others say that the Teflon washer between the spindle and bearing could cause that noise also. I usually put a trace of anti seize on the ones in my GS whenever I had it apart.