Changing diff fluid
Race Director
Joined: Sep 2000
Posts: 11,143
Likes: 1,913
From: Missouri City, TX
That's old information - GM issued a TSB with a new part number: Dextron LS Gear Oil 75W-90, part #88862624
There is no need to add friction modifier with the new stuff.
OP - It's a pretty easy process. The fact that GM went though several iterations of recommending different fluids before finally settling on this one tells me there was an issue there - why not run with the latest?
This member did a write up: LINK
There is no need to add friction modifier with the new stuff.
OP - It's a pretty easy process. The fact that GM went though several iterations of recommending different fluids before finally settling on this one tells me there was an issue there - why not run with the latest?
This member did a write up: LINK
See my Post #5. DEXRON LS GM part #88862624 is the correct fluid for any C6 vette for Diff fluid changes. Introducing the old stuff may cause chattering that many have complained about for years.
Team Owner
Joined: Dec 2002
Posts: 32,074
Likes: 296
From: San Francisco CA
Same here in my 2005. No problems with rear end. At 33,000 miles had factory fluid changed over to Amsoil Severe gear rear diff. fluid.
Race Director
Joined: Sep 2000
Posts: 11,143
Likes: 1,913
From: Missouri City, TX
AMSOIL Severe Gear 75W90 used in three different vettes with excellent results. My first AMSOIL purchase was for Severe Gear to stop a severe chattering of my 06Z and this was prior to the introduction of DEX LS fluid as factory fill for MY2009.
Race Director
Joined: Sep 2007
Posts: 16,557
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From: Peoria/Phoenix AZ
C6 of Year Finalist (performance mods) 2019
Way too many people get overly protective of their "special" low mileage car, but then treat their DD like crap and it never has problems.
Melting Slicks
Joined: Jan 2013
Posts: 2,576
Likes: 237
From: Murphy NC
The black stuff which came out after 10K miles is not anything I would want circulating for 100K miles in my car.
My Corvette is my driver, 24K since January.
Race Director
Joined: Sep 2007
Posts: 16,557
Likes: 2,108
From: Peoria/Phoenix AZ
C6 of Year Finalist (performance mods) 2019
With another 14K since the change, don't you think it's due again?
Melting Slicks
Joined: Jan 2013
Posts: 2,576
Likes: 237
From: Murphy NC
If I have to change it every 10 -15K to keep it quiet, I am good with that.
I have never had a car that didn't feel better after some fresh fluids.
Just my routine.
I am just happy my cars hold up with minimum trouble for the amount of miles I put on them.
With that said, the Corvette has been the worst car to date.
All of the other cars function properly without the massive amounts of repairs like I have had to do to the Corvette to keep it on the road.
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Thread Starter
Le Mans Master
Joined: Oct 2012
Posts: 6,391
Likes: 1,453
From: South Dakota
I did some looking around in the owners manual. I have a couple of questions...
1) I have a 2008 base coupe. Do all corvettes have limited slip differentials? If not, how do I find out if mine does?
2) Once the diff is completely drained and empty, how much is needed to fill?
Thanks guys!
1) I have a 2008 base coupe. Do all corvettes have limited slip differentials? If not, how do I find out if mine does?
2) Once the diff is completely drained and empty, how much is needed to fill?
Thanks guys!
Team Owner
Joined: Sep 2000
Posts: 25,022
Likes: 2,714
From: Far NW 'burbs of Chicago
St. Jude Donor '13
We had our 2009 changed at ~8k miles, using the GM 75-90. Then changed again at ~50k miles and sent a sample to Blackstone Labs. They said both the fluid and the diff itself were in excellent shape, and recommended going significantly longer before the next change.
Team Owner
Joined: Feb 2000
Posts: 45,479
Likes: 892
From: Texas
CI 1-4-5-8-9-10 Vet
St. Jude Donor '03 thru '10, '17
Is it true we don't need to add the friction modifier when using this new Dextron LS ?
Team Owner
Joined: Feb 2000
Posts: 45,479
Likes: 892
From: Texas
CI 1-4-5-8-9-10 Vet
St. Jude Donor '03 thru '10, '17
I did some looking around in the owners manual. I have a couple of questions...
1) I have a 2008 base coupe. Do all corvettes have limited slip differentials? If not, how do I find out if mine does?
2) Once the diff is completely drained and empty, how much is needed to fill?
Thanks guys!
1) I have a 2008 base coupe. Do all corvettes have limited slip differentials? If not, how do I find out if mine does?
2) Once the diff is completely drained and empty, how much is needed to fill?
Thanks guys!
Team Owner
Joined: Feb 2000
Posts: 45,479
Likes: 892
From: Texas
CI 1-4-5-8-9-10 Vet
St. Jude Donor '03 thru '10, '17
Melting Slicks
Joined: Jun 2007
Posts: 2,673
Likes: 9
From: Upstate New York
Drifting
Joined: May 2008
Posts: 1,462
Likes: 43
From: Choctaw Country
If you ever do the tranny try the Redline as well, shifts like butter.
Team Owner
Joined: Dec 2002
Posts: 32,074
Likes: 296
From: San Francisco CA
On my other car 15 years ago I used Redline MTL on 5 spd. manual trans. It shifted much better even after switching to factory new ATF then back to Redline for comparison purposes. I was going to sell the car back then because of this until I put in the Redline MTL fluid.About a year ago I had clutched replaced and gears were not smooth shifting. Put in new Redline synthetic Trans fluid and now it is smooth as ever. It saved me from selling the car again which is 25 years old now.
Melting Slicks
Joined: Jan 2013
Posts: 2,576
Likes: 237
From: Murphy NC
They are 7.00 shipped from Ebay.
Buy two.
When I did my AT I snapped off the top of one hitting the bottom of the car.
I look at them as cheap and disposable.
When they get dirty and nasty, I just throw them away and open a new one rather than waste time cleaning them.
Melting Slicks
Joined: Jan 2013
Posts: 2,576
Likes: 237
From: Murphy NC
The oil might still have life left in it, but if your car is chattering maybe you should replace the oil. As in my case.
I personally would rather replace the oil for 40.00 when the car gets noisy so I can drive a quiet car instead of paying 40.00 to get my oil tested and still be driving a noisy car because some lab tech said the oil was still fine.
If I had a car that was not making noise, I would still replace the oil at regular intervals just to help keep the differential somewhat clean and avoid any unneeded wear because I was too cheap to replace my fluids before they are 100% worn out.
But you keep paying the laboratory, they really like your money.
