Does the C5 use the same differencial fluid as a C6?
Thread Starter
Racer
Joined: Dec 2010
Posts: 250
Likes: 0
Does the C5 use the same differencial fluid as a C6?
I ask because i know that GM now uses a new fluid for the C6 but i dont know if that applies to the C5 as well.
Which ever fluid it is where can i pick some up?
Which ever fluid it is where can i pick some up?
Melting Slicks
Joined: Sep 2005
Posts: 2,568
Likes: 264
From: Near Charlotte NC
I use this in my 02Z06 & 03S2K.The C5 & C6 fluids are probably the same.The new GM fluid seems to be an upgraded/updated recommendation.
AMSOIL SEVERE GEAR 75W-90 Synthetic EP Lubricant (SVGQT)
As always,IMO.Opinions & Results Vary...
\db2
carolina
AMSOIL SEVERE GEAR 75W-90 Synthetic EP Lubricant (SVGQT)
As always,IMO.Opinions & Results Vary...
\db2
carolina
Tech Contributor
Joined: May 2008
Posts: 3,100
Likes: 17
From: Somers, CT and Clermont, FL
St. Jude Donor '09-'10-'11-'12-'13-'14-'15-'16
Premium Supporting Vendor
Joined: Aug 2001
Posts: 5,364
Likes: 38
From: King George VA
The answer is essentially yes. When the C5 came out the requirement was for a synthetic 75w90 and GM friction modifier additive. When the C6 came out, that remained the same. Then GM had significant problems with the C6 diff due to diff chatter and released several TSBs before releasing a new fluid with the friction modifier in it (listed above). So, this fluid is essentially backwards compatible with the C5, but doesn't need more additive like the C5 shop manual calls for.
Of note for those interested, the above listed GM fluid is very expensive. There are aftermarket alternatives for under half the cost:
AMSOIL Severe Gear Extreme Pressure Synthetic 75w90 (Product Code SVGQT)
Note: This fluid, like the GM Dexron LS, comes with friction modifier in it and extra is only rarely needed for the C5 diff. I run this fluid in my track day Z06 without extra modifier and have never experienced diff chatter. Similar in my 06 CTS-V, which was my daily driver from 06-09.
Of note for those interested, the above listed GM fluid is very expensive. There are aftermarket alternatives for under half the cost:
AMSOIL Severe Gear Extreme Pressure Synthetic 75w90 (Product Code SVGQT)
Note: This fluid, like the GM Dexron LS, comes with friction modifier in it and extra is only rarely needed for the C5 diff. I run this fluid in my track day Z06 without extra modifier and have never experienced diff chatter. Similar in my 06 CTS-V, which was my daily driver from 06-09.
__________________
C66 Racing #66 NASA ST2, SCCA T2
AMSOIL Dealer (Forum Vendor)
AMSOIL Preferred Customer Program (Members buy at Wholesale - a savings of about 25%)
C66 Racing #66 NASA ST2, SCCA T2
AMSOIL Dealer (Forum Vendor)
AMSOIL Preferred Customer Program (Members buy at Wholesale - a savings of about 25%)
Corvette Stories
The Best of Corvette for Corvette Enthusiasts
Top 10 Most Expensive Corvettes Ever Sold on Bring A Trailer
Brett Foote
10 Things Every Corvette Owner Needs (2026 Edition)
Michael S. Palmer
8 Most "Only Corvette Owners Understand" Quirks and Problems
Pouria Savadkouei
10 Reasons the C6 Z06 is Still A Performance Benchmark After 20 Years
Joe Kucinski
How Much Horsepower Every Corvette Engine "LOST" in 1972
Joe Kucinski
Top 10 DOs and DON'Ts for Protecting Your Convertible Top!
Michael S. Palmer
Top 10 Most Explosive Corvettes Ever Made: Power-to-Weight Ratio Ranked!
Joe Kucinski
150 hp to 1,250 hp: Every Corvette Generation Compared by the Specs That Matter
Joe Kucinski
8 Coolest Corvette Pace Cars (and Replicas) of All Time
Verdad Gallardo
Thread Starter
Racer
Joined: Dec 2010
Posts: 250
Likes: 0
The answer is essentially yes. When the C5 came out the requirement was for a synthetic 75w90 and GM friction modifier additive. When the C6 came out, that remained the same. Then GM had significant problems with the C6 diff due to diff chatter and released several TSBs before releasing a new fluid with the friction modifier in it (listed above). So, this fluid is essentially backwards compatible with the C5, but doesn't need more additive like the C5 shop manual calls for.
Of note for those interested, the above listed GM fluid is very expensive. There are aftermarket alternatives for under half the cost:
AMSOIL Severe Gear Extreme Pressure Synthetic 75w90 (Product Code SVGQT)
Note: This fluid, like the GM Dexron LS, comes with friction modifier in it and extra is only rarely needed for the C5 diff. I run this fluid in my track day Z06 without extra modifier and have never experienced diff chatter. Similar in my 06 CTS-V, which was my daily driver from 06-09.
Of note for those interested, the above listed GM fluid is very expensive. There are aftermarket alternatives for under half the cost:
AMSOIL Severe Gear Extreme Pressure Synthetic 75w90 (Product Code SVGQT)
Note: This fluid, like the GM Dexron LS, comes with friction modifier in it and extra is only rarely needed for the C5 diff. I run this fluid in my track day Z06 without extra modifier and have never experienced diff chatter. Similar in my 06 CTS-V, which was my daily driver from 06-09.
Can i pick up the Amsoil at a local parts shop? If i do need additive for the Amsoil which kind should i go with?
Tech Contributor
Joined: May 2008
Posts: 3,100
Likes: 17
From: Somers, CT and Clermont, FL
St. Jude Donor '09-'10-'11-'12-'13-'14-'15-'16
Price quoted per quart from: www.gmpartsdirect.com
GM PART # 88862624
GM LIST: $22.46
OUR PRICE: $13.06
GM PART # 88862624
GM LIST: $22.46
OUR PRICE: $13.06
Premium Supporting Vendor
Joined: Aug 2001
Posts: 5,364
Likes: 38
From: King George VA
If you have a C6, I'd get one bottle of this: AMSOIL Slip Lock Additive
If you want the GM fluid, the prices listed above for GMPARTSDIRECT are very reasonable - much lower than I've heard of dealership's selling that fluid for.
Premium Supporting Vendor
Joined: Aug 2001
Posts: 5,364
Likes: 38
From: King George VA
A few years old, but still a good read. If you discount the AMSOIL diff fluid, M1 75w90 was ranked above all others in this AMSOIL commissioned study:
AMSOIL Gear Lube “White Paper” (2 MB pdf file)
AMSOIL Gear Lube “White Paper” (2 MB pdf file)
Tech Contributor
Joined: May 2008
Posts: 3,100
Likes: 17
From: Somers, CT and Clermont, FL
St. Jude Donor '09-'10-'11-'12-'13-'14-'15-'16
A very interesting comparison. You do, however, need to remember that the testing was commissioned by Amsoil, and was not an independent study.
It would be interesting to see how the newest GM Dexron synthetic gear oil compared to the rest.
It would be interesting to see how the newest GM Dexron synthetic gear oil compared to the rest.
Premium Supporting Vendor
Joined: Aug 2001
Posts: 5,364
Likes: 38
From: King George VA
A few examples:
Castrol Loses Appeal on Sludge Claims
Truth in Advertising: BP vs. Royal Purple
Tech Contributor
Joined: May 2008
Posts: 3,100
Likes: 17
From: Somers, CT and Clermont, FL
St. Jude Donor '09-'10-'11-'12-'13-'14-'15-'16
