Pop sound in rear end when turning left

[914eener]

Stock 99 with 70k miles. When I make a left turn at any speed I've started getting one pop sound that seems to be coming from around left side of the differential. Doesn't do it when I turn right. It only pops once per turn but does it every time no matter how long the car is driven. Not speed dependant as it does it no matter the left turn speed. Even does it at less than 5 mph in my parking garage at work. Sounds like something gets bound up and breaks loose causing the pop sound. I checked to see if anything was loose and it's not. U joints seemed to be fine, boots not torn. No leaks. The last time I changed the differential fluid was at 30k miles so it's time. Changing it tomorrow to Royal Purple 75-90. The car only gets driven appx 60 miles once every week or so.

Any ideas on this?

[c4c5specialist]

HI there,

I wouldnt use Royal Purple at all.

88862624 is the correct part number and does not require additive.

As for the rest, have you had any suspension work done in the back ???

Allthebest, c4c5

[914eener]

Bilstein sports at 60k miles and Z06 sway bar and links.

What's the problem with RP in the diff?

[c4c5specialist]

HI there,

The friction modifier is not of the correct type and will, under stressful conditions, overheat the preload washer within the differential.

I would really be checking the endlinks for correct fastener torque, as well as the lower shock mounts.

Allthebest, c4c5

[ROSSO Z]

My 02 had the popping rear end after I used a BG product. I had to flush the rear end twice and added double the friction modifier to make it stop. After a few K miles, I flushed again and added the standard amount of friction modifier. No problems since.....

Cheers,