Clicking from rear when backing up - R200LSD or U-joint?

[jgkurz]

Hi All,

I have a strange noise from the rear of my 77z when backing up. The description is very similar to the below thread however my drive shaft is not hitting my swaybar.

 

http://forums.hybridz.org/index.php?/topic/74366-clicking-noise-when-backing-up

 

In summary, I hear a click clack click clack from the rear of my car when I back up the car. It happens often but not every time. On a rare occasion I can hear it slightly going forward. I only hear the clicking after letting the clutch out at low speeds in 1st or reverse. I'm am positive the rear CV shafts or brakes are not to blame. I believe the problem is either the R200 LSD or a U-Joint.

 

I put some hard miles on my car at a track day and since then I have noticed the click clacking.

 

Questions:

 

1) Could worn or slightly low diff gear oil cause my LSD clutches to make this noise? I use Amsoil synthetic without a friction modifier (as recommended)

 

2) If it's a U-Joint, I assume I take the drive shaft out and check for smooth moving joints?

 

3) Could a wheel bearing cause clicking? When the car is jacked up the wheels spins freely and without freeplay. Not a fun job to change one of these.

 

 

Thanks!

Edited April 24, 2010 by jgkurz

[JMortensen]

The LSD does absolutely nothing unless you're turning.

[badjuju]

sounds stupid, but it could be one of your driveshaft to diff bolts sliding back and forth in its hole. I had this happen once, really strange noises, like the ones you're describing.

[jgkurz]

The LSD does absolutely nothing unless you're turning.

 

Thanks Jon. I was hoping you'd see my post and reply. Actually I'm glad to focus on something other than the diff. Much cheaper..

 

sounds stupid, but it could be one of your driveshaft to diff bolts sliding back and forth in its hole. I had this happen once, really strange noises, like the ones you're describing.

 

Interesting. I will pull the driveshaft to inspect the u-joints and bolts. That would be any easy fix.

Edited April 24, 2010 by jgkurz

[jgkurz]

As a final effort I replaced the left rear wheel bearing. Guess what, no more clicking. I wish I would have changed them from the start. Oh well.

Edited August 29, 2010 by jgkurz

[Savage42]

At least you figured it out! I hate when that kind of stuff happens! At least I replaced ALL wheel bearings during the build.