Differential fluid change, Dexron LS Gear Oil done

[george]

Was done today. Axle Chatter/Clanking rear end noise GONE. Under warranty Bulletin ID# dated 01/09/2008, #2048181. Drain/flushed and add just under 3 quarts of GM Dexron LS Gear Oil P/N 88861624. No additives.

Picked up the C6 Z06 and did 8-10 figure 8's in the dealerships back parking lot. This got my posi unit lubricated well. Drove home approx. 20 miles. No rear end noises now. Turns no clanking or thrashing sounds either.

Shifting in traffic from 1st to 2nd gear NO more pounding like pinion bashing. No clanking in the rear end at all. Tranny is quiet.

So for 20 miles I'm happy. If this new fluid fails me I'll post but so far it's done well .

[seamus2154]

Sounds good, keep doing those tight circles or 8's it takes a bit to work it in. You should be good. I went w/ Amsoil for the rear and trans and 400mls later still good, we'll see.

[zeta08]

OK, don't flame me, but what is the diff chatter? Is it all the time, and not just when you are dragging the car? Does it effect certain years?

Also, if you aren't adding additive, are you less limited, or more limited. That is, do you know if you have more lock-up or less now compared to stock? Are you trading quiet for loss of lock-up?

Thanks for the info in advance, and keep updating on your new fluid...I've found that for me, I think there's a big improvement initially, but then I realize not much has changed...I hope you don't find this to be your situation...

[seamus2154]

It could be any year but the 06-08's have had some. The chatter is in the rear and it's the clutch plates. You will hear it when turning because the inside tire has to turn more slowly than the outside which has to go faster. So the inside has to slip to accomplish this, thus the clutch plates. The addative helps the slip but you don't want to add more than you need if any depending on your fluid spec.. Some fluids have some built into the formula. The reason for the 8's and circles is to work in that addatve to the plates so they let go and slip a little. If they dont slip they stay locked and then chatter. When going straight or dragging you really won't hear anything because the tires are at the same speed and the clutches arent slipping for the most part. That's why some guys drive the car mostly hwy and have this problem but haven't done many tight turns to have ever worked the fluids in. GM changed the fluid type so that must have been part of the problem.

[GOLD72]

I have got 6500 miles now on my AMSOIL Severe Gear fluid change as a DIY. Still quiet on this DD mostly freeway car. Previously the chatter was so loud as to be embarrassing inside the office garage. Dealer fluid change 16 months ago failed to work for very long with the chatter coming back louder than before after a couple of months.

[seamus2154]

Originally Posted by GOLD72

I have got 6500 miles now on my AMSOIL Severe Gear fluid change as a DIY. Still quiet on this DD mostly freeway car. Previously the chatter was so loud as to be embarrassing inside the office garage. Dealer fluid change 16 months ago failed to work for very long with the chatter coming back louder than before after a couple of months.

I love Amsoil and have used it in all my vettes and now I'm going to put it in my new GMC 1500 which is noisy. Subdriver (Amsoil vendor) advised me for the new c6z to use sever gear w/ one bottle of posi which is working like a charm>

[MikesZ06]

Originally Posted by george

Was done today. Axle Chatter/Clanking rear end noise GONE. Under warranty Bulletin ID# dated 01/09/2008, #2048181. Drain/flushed and add just under 3 quarts of GM Dexron LS Gear Oil P/N 88861624. No additives.

Picked up the C6 Z06 and did 8-10 figure 8's in the dealerships back parking lot. This got my posi unit lubricated well. Drove home approx. 20 miles. No rear end noises now. Turns no clanking or thrashing sounds either.

Shifting in traffic from 1st to 2nd gear NO more pounding like pinion bashing. No clanking in the rear end at all. Tranny is quiet.

Mine was the same after I had the fluids changed under the GM TSB. Thought all was well. Two months later, 'clanking" returned...

Mike