DAKING

I've read a lot of posts about the clutch plates noise and possible soloutions. T he one that seemed to work the best was the one about AMSOIL additive,so I went looking for it, tuff to find a dealer around here but finally found one. I was talking with the owner of the store (sells bikes and snowmobiles) and apparently they use a lot of the products. Well ,he says that the noise could be from air being trapped in the differential ,he says that the additive takes the air out and after awhile it does comes back . Not being an engineer or a mechanic is this a sound theory ? (please i am only a messenger)

ipmtim

I don't know about the air in the system and I intend to switch over to some type of synthetic lube for the rear end.
Also there is a TSB on the rear end noise, I would take it to the dealer and let them change the flluid under warranty for two reasons.
One its free and the other is that now there is a record of the noise if there is a problem with the rear end later.
I had the dealer change mine at about 13K and at 17K the noise is starting up again.

vettemaster1

posi chatter/noise has been around as long as posi's have...the gm fluid is synthetic...every now and then find a deserted parking lot and do some figure 8's....this helps get the lube in between the posi clutch plates and reduces chatter/noise

C66 Racing

I think he is way off base. The diff will always have air in it. It isn't a system that this filled solid with fluid. The C5 Z06 diff has a vent plug on it. Air doesn't have anything to do with it.

The friction modifier changes the fluids coeficient of friction to prevent the clutch plates from chattering as they rub against each other when the wheels are rotating at different speeds. You can read a little about it on this link:
AMSOIL Slip-Lock Differential Additive

69 Vette

does this noise you guys speak of sound like a "howling" type noise when you turn a corner?

KRAYZ308

I had mine to the dealer a couple of weeks ago for a four wheel alignment. I mentioned to the service writer that they changed the diff fluid and added the friction modifier back in November because of the clunking noise. It got better but still makes some noise. He said that GM now has yet another lube to address the problem. So, they changed the fluid again with the new stuff. It works very well so far.

dpracing

GM's Dexron LS cures the rearend chatter at slow speeds. Had it put in my 07.

Its also in my 09, (factory fill) and thank god its quiet.

AtlBlkZ06

I think its because I always get lost and make U turns, but can someone record this noise?

Thanks!