Gear oil change intervals in track driven cars
 

I've got Redline in my transmission and after a few track days the shifting is starting to get rough again. I've been told that Redline goes bad after one good heating, and while that sounds iffy, how often should you change the tranny fluid in a car that's been tracked and raced?

I only have a viscous LSD. I spoke to a guy from ATS (he was a little weird) and he said with their LSD you had to change the diff oil over 3000 km!!! That's like 2000 miles!

I guess I should be glad I have a stock diff, 4 quarts of Redline costs about $100 when it's on sale.

Redline MTL is a 75/80 so rather thin. MT90 is a 75/90 so thicker.

My trans with MTL run for many years killed the bearings around 100k miles and many many track days so definitely use something thicker than MTL and change at least once a season.

I've got 75/90 NS not MTL.

Plus this is a transaxle not a tranny and diff separately.

And I was asking because it's only been a few thousand miles and I wonder if transmission oil can actually go bad this fast when driven hard.

Especially considering the service interval for normal driving is 50,000-100,000 miles which is more than what the car has on it all together.

i think the normal service interval for the diff/trans is 30K. racing depends on the driver/HP, but a turbo FD might need every other track day, while a pro7 car could probably go the whole season

Seems like redline kills our trans bearings.

Killed mine, read that it killed several others on this board when searching.

The car in question isn't an RX-7. I just want to know if a turbo car without an aftermarket LSD will actually wear out transmission fluid (enough for full-throttle shifts to start grinding again) within 3-4 hours of track time. It's an MR-2 so the transmission would end up getting extra hot.

Yes. Overheating the gear oil will cause it to breakdown. Put a temp sensor on the tranny if you want to be sure.

I use synthetic gear oil in my diff and tranny and change them every weekend, along with motor oil and brake fluid. Better to change fluids too often than not enough.

Yeah, I change oil basically every track day now (I start buying it in bulk whenever I see it on sale...hehe). I go and do a single 30-minute session (the nice thing about tracks here), I might wait, but I usually bleed the brakes every time I do a dry track session... I only change the filter every other change because the oil filter on my car makes a huge f*cking mess when I take it off. I also started buying cheap filters bulk online, along with washers so I don't have to go and pick them up at $1.50 a piece any more. I'm waiting on the washers to come to change the oil...

Good tranny oil is $$$ here, though... 4 quarts of Redline gear lube is like $100 installed at the very least. It's over $160 if you pay full retail!!! This time I'm trying lightweight shockproof to see how it is.

I don't have any temp gauges, and don't want to spend the time and money required to install them on a car I'm gonna have to sell eventually...

i think you're answered your own question

Yup, transaxles combine the transmission and the differential. Therefore the fluid is doing doubleduty and if your running the differential hard, the fluid is going to burn up and affect your shifting. I would suggest a cooler but since your getting rid of the car....

Can you get Amsoil Transaxle lube? or Motul? Either will resist breakdown better than Redline.

God, Redline is already $$$ enough here as it is... But I guess nothing costs as much as Wakos, which is a total racket.

You should consider the temp sensors. Early warning is definitely gonna help your resale value. as opposed to too late.

I agree with HotRodMex. I use Amsoil 90 weight. Great struff and I change it once a season (4-7 weekends).

If your transaxle is overheating the oil, a cooler and pump would be alot easier and cheaper in the long run than changing gear oil every event.

If anything I need to buy an oil cooler or at least a gauge first...


BTW, does everyone change their engine oil every track day? Or is there some leeway there?

I think the proper thing to be done here is to spend the money on an oil analysis to actually know what condition the oil is in. It's on my list of things to spend money on, but for now I'm just playing cautious.

Also, I'm just a stock N/A and run Amsoil everywhere, so I really don't have much to worry about