Diff noise
 

I figure to post this here since some of you has broken plenty diff's

I have S4 clutch type LSD on my FD rear, and after a few passes on the track it is now making noise. It sounds like a bad bearing- Woo Woo Woo sound lol..
When the car is moving and applying force to the diff it does not make noise, it only does it when rolling free and car is on neutral. Also it does not do it in reverse at all even when is rolling in neutral!
I know I have to open it up and look but just wanted some pointers!!!

Did you use LSD additive?

Negative just gear oil, mobil high performance 80-90 I believe
Funny thing is I been running this diff for like 3 yrs with no problems. I replace the fluid the night before the track, on one of my passes I wheel hopped bad and when I got off the track driving back to the pits the noise started. At first I though it was just the tires sticking to the asphalt. I still ran another two passes with the diff like that and nothing Happened, doesn't feel any diffrent..

Some gear oil has the additive already in it. I would check and if doesnt, go buy some and throw it in there.

if it does it while driving in a straight line i highly doubt it is the clutches making the noise but the gear lash for the decel side of the pinion is running off the gears.

drain the oil and check it for metal, or worst case remove the third member and check the gear pattern again. sometimes when preloading the gearset if the adjuster rings are just a hair too tight and you back them out, once you apply enough force the outer bearings will push the slack in the collars out and create more slack which will upset your preload and gear patterns. that is if the gearset uses the threaded adjusters versus the solid shims, which i cannot recall which the FD has at the moment(the older 7 diff's had the threaded adjusters).

It only does it when there is no force applied to the diff, only rolling on neutral.
Does not make noise on reverse.
I will pull the diff cover and see!! Thanks

jason i have auto diff if you want... call me