TnRZ06

very good detailed write up

oicw

Just did this a couple hours ago; squeezed in all 3 quarts of the proper GM stuff. Drives like a new car now!

No more chatter, noise, and bind. Car is much more refined. Could be my imagination but the good'ol T56 is shifting smoother as well, don't know if that's possible.

The previous owners must've put in some high incompatible fluid. I had so much bind that on a slight hill the car won't roll back with the wheels turned. It chattered so bad the whole car would shake.

Bedouin

Question for the collective, I just changed out the the original rear diff fluid on my '12 GS (6spd manual) at 16k miles & it looked pretty damn clean, a silver-grey-moly color & no hint of blackness or any crud...indeed it looked perfect & as I might expect it at new.
I re-filled it with the recommended GM#88862624 which is a light golden brown & it's a very different color...is this the same fluid they fill the diff with at the factory? Could the old fluid have been that golden brown originally & just aged into that silver-grey-moly color from the diff internals in 16k miles?

Mark2009

Yes.

AzDave47

The new fluid is the right part number, so the difference should be changes with use.

Jcbarr25

Is the dealer, the only place to order the retaining pin from? Also, how can we check what fluid needs the additive? I would like to use Mobil1 syntethic gear Lube 75w-90. Good? Bad? Also, do I need additive for the limited slip?

Bedouin

I would stick with the GM fluids as they're partially designed for the components & vice versa.

AzDave47

and they already have the proper additives for the Z06 dif.

There may be some other source for that clip, but I have not seen it mentioned. Some forum members have tied a colored thread on it to help keep track of it. When I did the fluid change I was able to keep track of it, but sometimes s**t happens.

If you have an 09 or newer Z, the dif drain comes out the back of the dif, not the bottom. You cannot pull the connection all the way out because of the lower sub-frame mount, but you can hold it out far enough for the old fluid to drain out.

Also good policy for draining these fluids: make sure you can loosen the fill plug BEFORE you drain the fluid. It sucks if you get the old useable fluid out and then find the fill plug is frozen or corroded in place.

acrace

Been there, done that. '92 Z07 six speed. Although only a year old, couldn't get the manual trans fill plug out!

AzDave47

Our '10 Forester (AZ car) rear dif plugs required an impact gun to get the top and bottom plugs out. If it had been the Z, I would not have been able to use an impact gun.

Jcbarr25

Yeah. I got a 10 GS which should be the same rear end as the Z06. So the drain plug is in the back? Errr

Well this might be stupid, but its ACdelco the GM care brand? I found the fluid in amazon but its ACdelco. Is that the same as the GM care posted on this thread?

AzDave47

I did mine a couple years ago and it was GM. If what you get is listed as AC Delco, as long as it is the correct PN you should be fine.

Jcbarr25

Cool. Thanks. I will get it. I want to change my tranny and differential fluids when I do the oil change. I am storing the car for over six months due to a deployment. Want it it to sit with new fluids.

Boxcar

OK, great thread, read every post, before I get started on changing my dif and trans fluids. I have a 2010 M6 GS, I bought Mobil-1 75W-90 LS for the dif.

So my chatter on here about the correct fluid, can any one offer that this is a good/great product to use?

Headed off to get some clips to have on hand with string attached...great idea...with florescent orange paint!! I'll look of the 3 indexes and get a pic if possible.

I just hope that the GS and Zed 06 are more of the same then not minus engine of course.

Jcbarr25

Yeah. It should be similar. The differential cooler has a drain towards the bottom which makes it easier

Boxcar

Thanks...
Got to love the forum and its people!

KnightmareCS

I'd just get the GM fluid not knowing the composition of Mobil1.
Amazon has it pretty cheap.

Boxcar

According to GM DEXOS Quality Assurance Program: http://www.centerforqa.com/gm/dexos1-brands

There are quite a few brands that meet the standard...check it out you might be surprised.

Dougpaper

Remember to do figure 8's until you puke after the change. My dealer is a master corvette specialist and he told me that will get the fluid into all the plates. I found a large paking lot and just did about 10 minutes doing fugure 8's

1972bluelt1

I e-mailed Mobil1 a couple of years ago. They said use the GM fluid.