If you go to the track you will obviously be doing it more often(or at least you should ). Brad Neff ("SubDriver") is a forum regular, a successful racer (SCCA T1), and he has had better results with his maintenance routine than most. I put a lot of weight into what he says and does. Since I go to the track for DE's and open lapping days, I follow his advice and change the fluid every three weekends (6 days of track time). By the way, I also get all my fluids from him. I like supporting his Amsoil business, which in turn supports his race team and this site. :z:
If you don't go to the track, it still depends on how hard you run your car on the street. I have the three-volume shop manual set at home, and I can see what it says. Someone will probably beat me to it, and post the info.
For moderate driving with an occasional spirited outing on the street, I would probably change the differential and tranny fluid every 20K miles. I know some guys who do it as often as every 5K, which is a bit much, especially if you are using a good synthetic.
Depends how you use your car.
Heat is the enemy.
Regular driving ... would say parallel the Tranny change. IMO
Track it? Listen to DJWorm, SubDriver, others here with cred on this.
Thanks for the plug and the support! :cheers:
As stated, I am on the extreme of use. I change my tranny and diff fluid about every 6-8 track days. My tranny and diff held up to about three and a half years, 16k total miles, 27 or so SCCA races and something like 9 DEs. After I lost the left axle seal in my last race and subsequently lost about a quart of diff fluid (but won the race), I decided enough was enough. While I am in training for the next six months, I am having my tranny and diff rebuilt as a preventative measure.
I have been running synthetics in both my tranny and diff since the 800 mile mark.
Been using AMSOIL since before my 04 season.
For a street driven car, my suggestion is about every 30k miles. The diff sees more heat than probably expected and AMSOIL now considers high performance street driven cars like our as the most severe service for diff fluid. Last fall they upgraded their diff fluids.