I could have sworn I've answered this before, but what the heck, a moderator is asking.Curious as to why you or others believe the the transaxle oil is in need of change? How are you making that determination?
Redline will tell you specifically what the base stocks they use are. The other brands won't, especially Mobil-1, which has been very cagey the past few years about just how synthetic their lubricants really are. What the heck is "tri-synthetic" anyway? Castrol, Royal Purple, Mobil, Chevron, Shell, Total, Quaker - and most other brands try to be mysterious. Amsoil and Redline are the only two brands I'm aware of that talk the talk. I like transparency.Can you tell me why you prefer the Redline oil over Castrol and Mobil products?
Are there any Pics or Diagrams out there on this mod?If all you're doing is changing the tranny oil, you can save a lot of time by making a 2" hole through the reinforcement plate under the drain plug. I used a hole saw, with the hole's center located about 3/4" left and 1/4" forward of the drain hole in the plate (basically, I just enlarged the drain hole). With a little care, there's plenty of room between the plate and the tranny to clear the center bit of the hole saw. Once you have access to the drain plug, everything can be done without any further disassembly or modification.
My 2011 Sypder at ~21,000 miles is on its third fresh trans oil. What it came with, the one the prior owner did at 12,500 miles and the one I did at ~20,000. The car has seen a number of track sessions. I was very happy to have replaced the fluid. I don't know or care what the factory service interval is. When I drained it, it looked dirty (doesn't it all) and was glad to get new Redline trans fluid in there. $70, an overnight drain, done. Was it necessary for peace of mind? YES. Was it technically needed? hmm, Blackstone Labs said "...no issues", but here's the enitre "comments" section...:how often should you chance the gear and or transmission oil?
Probably not. If you're worried for some reason change it and send a sample off to Blackstone. For normal street driving you'll likely be fine with the factory recommendations. That's not to say that changing more often will hurt anything and may add a bit of safety margin. With harder use, track for instance, changing more often is a good idea and is also typically recommended by the factory. I don't recall what the recommended interval is offhand but it is rather long. You should be able to find this in the warranty/maintenance book that should have come with the car or in P9's Files section if the manuals didn't come with the car.thanks for the reply, should this apply even on non tracked vehicles? neither I nor previous owner ever tracked the car, I'm in 46k miles, with no history of tranny/gear oil changes yet... is my drivetrain about to blow up?