[Z06] Fluid Change
Thread Starter
Racer
Joined: Nov 1999
Posts: 346
Likes: 10
From: Easton MA
Fluid Change
Time to change my transmission and diff fluid in 02 Z06.
Plan on using
Mobil 1 ATF 98HC69 for tranny
Mobil 1 LS 75W-90 for rear diff
Anyone have experience with these products?
Thanks
Plan on using
Mobil 1 ATF 98HC69 for tranny
Mobil 1 LS 75W-90 for rear diff
Anyone have experience with these products?
Thanks
Team Owner
Joined: May 2002
Posts: 128,074
Likes: 42
St. Jude Donor '10-'11-'12-'13-'14-'15-'16-'17-'18-'19
Pep Boys does all of my fluid changes. When they are busy, I run by Home Depot and get and hire an illegal alien to crawl under the car while I add fluid from above. The parking lot at Home Depot is paved with asphalt, a petroleom related substance. The oil, coolant, tranny fluid, etc., eventually soak into the same, especially in hot weather.
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Drifting
Joined: Jan 2008
Posts: 1,722
Likes: 138
From: Florida
St. Jude Donor '09
Don't fall for the the hype of the boutique oils, the off-the-shelf Mobil 1 products are more than adequate.
Tech Contributor
Joined: Jan 2004
Posts: 20,030
Likes: 289
From: Wylie TX --> Less is More, except under the hood !
Amsoil here....
Procedure on my web site if you want to see some tips on replacing the fluids.
www.ToqueZ06.com
Toque
Procedure on my web site if you want to see some tips on replacing the fluids.
www.ToqueZ06.com
Toque
Thread Starter
Racer
Joined: Nov 1999
Posts: 346
Likes: 10
From: Easton MA
Thanks for the reply. I assume the LS 75W-90 contains the correct amount of limited slip additive.
I agree about boutique fluids. Like the people who change Mobil 1 oil every 2000 miles.
Drifting
Joined: Jan 2008
Posts: 1,722
Likes: 138
From: Florida
St. Jude Donor '09
"Mobil 1 Synthetic Gear Lube LS 75W-90 contains special friction modifiers designed for limited slip-type differentials. In most applications, the addition of special LS (limited slip) additives is not required. For axles requiring the highest level of limited-slip performance, OEM specific LS additives can be added to this fluid."
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Joined: Dec 2010
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2020 Corvette of the Year Finalist (performance mods)
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i change mine maybe every 500 miles lol... i don't drive my car much at all so once it gets to a dark bronze color i change it or if the oil % gets down to about 80 or so from starting it up and letting it run in the garage to keep the fluids cycled... it usually ends up being 3 times a year so it's not like i'm spending a ton of money... the trans, diff, and coolant i'll do once a year
Burning Brakes
Joined: Jun 2004
Posts: 1,184
Likes: 3
From: KADS- If it has wings or an engine, I can break it. Dallas TX
Use the GM red stuff for the tranny. I changed fluids in the rear and tranny using Mobil1. The tranny was a touch smoother on shifts, a benefit from the the synthenic fluid. BUT, the f***ing front seal started leaking 2 days later. Switched back to GM fluid, but too late, it still leaves a drop on the garage floor after driving it.
I say if you have been using the GM fluid for ten years, why change now? But who knows, you could change to a full synthenic fluid and it might not leak. THese cars are getting kind of old. Think about the age and condition of your seals???
YMMV
Best of luck
I say if you have been using the GM fluid for ten years, why change now? But who knows, you could change to a full synthenic fluid and it might not leak. THese cars are getting kind of old. Think about the age and condition of your seals???
YMMV
Best of luck
Premium Supporting Vendor
Joined: Aug 2001
Posts: 5,364
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From: King George VA
It may, but I added the OEM recommended LS additive anyways and this is why. From Mobil's product data:
"Mobil 1 Synthetic Gear Lube LS 75W-90 contains special friction modifiers designed for limited slip-type differentials. In most applications, the addition of special LS (limited slip) additives is not required. For axles requiring the highest level of limited-slip performance, OEM specific LS additives can be added to this fluid."
"Mobil 1 Synthetic Gear Lube LS 75W-90 contains special friction modifiers designed for limited slip-type differentials. In most applications, the addition of special LS (limited slip) additives is not required. For axles requiring the highest level of limited-slip performance, OEM specific LS additives can be added to this fluid."
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Drifting
Joined: Jan 2008
Posts: 1,722
Likes: 138
From: Florida
St. Jude Donor '09
There is a performance downside to adding too much additive. Too much friction additive can result in the diff clutch plates slipping more than designed, thus your limited slip diff becomes less limited slip (more open). In our C5 Z06 the diff is supposed to transmit 75 ft-lb of torque to the tire with grip (as opposed to 0 ft-lb in an open diff). Too much additive can lower that to something less than 75 ft-lb. While most will never notice this on the street, at a road course or drag strip, it can make a difference as the tire with grip won't get as much forward force and the unloaded tire (inside tire in a tight corner) will just spin. Won't hurt the diff to have to much and if it is more important to you to prevent diff chatter (an annoyance) than more might be better. But to maximize performance, you want just enough to prevent diff chatter.
Melting Slicks
Joined: Jun 2004
Posts: 2,836
Likes: 110
From: El Paso TX.
There is a performance downside to adding too much additive. Too much friction additive can result in the diff clutch plates slipping more than designed, thus your limited slip diff becomes less limited slip (more open). In our C5 Z06 the diff is supposed to transmit 75 ft-lb of torque to the tire with grip (as opposed to 0 ft-lb in an open diff). Too much additive can lower that to something less than 75 ft-lb. While most will never notice this on the street, at a road course or drag strip, it can make a difference as the tire with grip won't get as much forward force and the unloaded tire (inside tire in a tight corner) will just spin. Won't hurt the diff to have to much and if it is more important to you to prevent diff chatter (an annoyance) than more might be better. But to maximize performance, you want just enough to prevent diff chatter.
Premium Supporting Vendor
Joined: Aug 2001
Posts: 5,364
Likes: 38
From: King George VA
