Changing the differential oil ?
Thread Starter
Race Director
Joined: Aug 1999
Posts: 11,121
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From: SE Pennsylvania
St. Jude Donor '03 thru '26
Oldtimer
Changing the differential oil ?
I was looking for the Limited slip oil, but there's a lot and I don't see the fluid type od GM Part # Can someone help me ?
How long does Gear oil last, My car is 22 years old, and it only has 11K miles. I don't think I ever asked this question ?
How long does Gear oil last, My car is 22 years old, and it only has 11K miles. I don't think I ever asked this question ?
Last edited by killain; Oct 24, 2025 at 05:51 PM.
Drifting
Joined: Sep 2022
Posts: 1,449
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GM part number has changed, twice I believe, but you don't need it.
75w90 NAPA or valvoline LS lube is all you need, has the friction modifier mixed in already, takes just under two quarts.
My diff fluid change video...
75w90 NAPA or valvoline LS lube is all you need, has the friction modifier mixed in already, takes just under two quarts.
My diff fluid change video...
Le Mans Master
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From: Akron Ohio
2025 Corvette of the Year Finalist - Modified
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St. Jude Donor '09-'10-'11
A lot of good oils already have the limited slip additive in it.
I like to use AMSOIL in my car and no additional additive is needed.
https://www.amsoil.com/p/amsoil-seve...-EA?zo=1934716
I like to use AMSOIL in my car and no additional additive is needed.
https://www.amsoil.com/p/amsoil-seve...-EA?zo=1934716
Thread Starter
Race Director
Joined: Aug 1999
Posts: 11,121
Likes: 672
From: SE Pennsylvania
St. Jude Donor '03 thru '26
Oldtimer
OK great, there are some GM Limited slip fluids on the market and with each a different number. Thank's. I wonder why there are so many GM Limited slip-oils with different part numbers ?
Last edited by killain; Oct 24, 2025 at 02:36 PM.
Drifting
Joined: Sep 2022
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There really is no good reason to use the more expensive GM lube, the Valvoline is perfectly acceptable and best price,
Le Mans Master
Joined: Oct 2007
Posts: 9,700
Likes: 3,469
From: Akron Ohio
2025 Corvette of the Year Finalist - Modified
2024 C5 of the Year Winner - Modified
2023 C5 of the Year Finalist - Modified
2022 C5 of the Year Finalist - Modified
St. Jude Donor '09-'10-'11
Drifting
Joined: Sep 2022
Posts: 1,449
Likes: 1,114
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