trans / diff fluid change
Thread Starter
Racer
Joined: Aug 2008
Posts: 367
Likes: 0
From: Sacramento ca
trans / diff fluid change
I have a 99 M/T vette. What is the normal interval to change the trans and the rear diff fluid? What fluid is generally used. It is a F/I car with 500RWHP if it changes what fluid is uded.
Thanks
Toby
Thanks
Toby
Le Mans Master
Joined: Sep 2007
Posts: 7,604
Likes: 8
From: Belleville Il
I'd say on a higher performance car as yours,,assuming you do put some miles on it(not a garage queen) I'd do it every year as cheap insurance.The change is not hard to do as both unites have drain and fill plugs. I don't have your performance level(not even close),,I've had good results with Royal Purple Syncromax for the tranny,,PR 75-90 Max-gear for the rear. Amsoil products are another popular choice. I'm sure there are others. As stated I've used RP products and there are LOTS of Amsoil fans here on the forum!! Hope this helps!!
Burning Brakes
Joined: May 2003
Posts: 970
Likes: 0
From: Montgomery AL
If your car is a daily driver, then every 40K miles is fine. Corvette owners really go overboard changing it more often than necessary.
I used Amsoil but will probably go with Royal Purple next time because its easier to find and a little less costly...
I used Amsoil but will probably go with Royal Purple next time because its easier to find and a little less costly...
Premium Supporting Vendor
Joined: Aug 2001
Posts: 5,364
Likes: 38
From: King George VA
Toby,
The 99s have paper blocker rings in the manual tranny. Many posts on the forum indicate that several basestocks used in ATFs are not compatible with these blocker rings causing them to swell and resulting in tranny failure. There is a decent discussion of this in the sticky thread "weights, measurements..." at the top of the C5 section. AMSOIL's Group IV PAO basestock seems to get good reports from those with paper blocker rings and numerous forum members are using AMSOIL tranny fluids.
For your tranny I'd recommend:
AMSOIL Torque-Drive Synthetic Transmission Fluid (product code ATD1G)
This is a Dexron III fluid with no viscosity modifiers thus is extremely shear stable. I'm currently running this fluid in my 06 CTS-V daily driver with the same Tremec 6-speed as in the C6 Corvette.
For your diff I'd recommend:
AMSOIL Severe Gear Extreme Pressure Synthetic 75w90 (product code SVGQT)
I run this diff fluid in both my CTS-V and my 02 Z06 track car and have had no diff failures (other than the common C5 left axle seal leak) in my Z06 diff in 30+ races. This fluid comes with friction modifier in it and I don't use extra additive in either my CTS-V or Z06 (though for C6 owners I do recommend a bottle).
For the DIYer, this comes in handy:
AMSOIL Hand Pump (product code G2039)
Ordering info to benefit the forum in my sig.
The 99s have paper blocker rings in the manual tranny. Many posts on the forum indicate that several basestocks used in ATFs are not compatible with these blocker rings causing them to swell and resulting in tranny failure. There is a decent discussion of this in the sticky thread "weights, measurements..." at the top of the C5 section. AMSOIL's Group IV PAO basestock seems to get good reports from those with paper blocker rings and numerous forum members are using AMSOIL tranny fluids.
For your tranny I'd recommend:
AMSOIL Torque-Drive Synthetic Transmission Fluid (product code ATD1G)
This is a Dexron III fluid with no viscosity modifiers thus is extremely shear stable. I'm currently running this fluid in my 06 CTS-V daily driver with the same Tremec 6-speed as in the C6 Corvette.
For your diff I'd recommend:
AMSOIL Severe Gear Extreme Pressure Synthetic 75w90 (product code SVGQT)
I run this diff fluid in both my CTS-V and my 02 Z06 track car and have had no diff failures (other than the common C5 left axle seal leak) in my Z06 diff in 30+ races. This fluid comes with friction modifier in it and I don't use extra additive in either my CTS-V or Z06 (though for C6 owners I do recommend a bottle).
For the DIYer, this comes in handy:
AMSOIL Hand Pump (product code G2039)
Ordering info to benefit the forum in my sig.
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C66 Racing #66 NASA ST2, SCCA T2
AMSOIL Dealer (Forum Vendor)
AMSOIL Preferred Customer Program (Members buy at Wholesale - a savings of about 25%)
Racer
Joined: May 2003
Posts: 257
Likes: 0
From: Roseville CA
FYI Toby,
Your trans fluid and rear diff fluid was replaced (as was the tranny & diff) with Amsoil within about 2000 miles prior to you buying it. Unless you've put on 40,000 miles in the last 10 months, you should really be fine for quite a while. I put good stuff in there.
Let me know if your in need of a clutch replacement. I still have that Luc Stage II clutch sitting in my garage. I need to get rid of it.
-Keith
Your trans fluid and rear diff fluid was replaced (as was the tranny & diff) with Amsoil within about 2000 miles prior to you buying it. Unless you've put on 40,000 miles in the last 10 months, you should really be fine for quite a while. I put good stuff in there.
Let me know if your in need of a clutch replacement. I still have that Luc Stage II clutch sitting in my garage. I need to get rid of it.
-Keith
