NO FRICTION MODIFIERS OR "LSD" FLUIDS!!!!

I have many track miles on a Pro2 in my car. Actually 2 of my cars...

FWIW I've been using Motul Gear 300 75-140 the last few changes and like it better than Delvac. Hot they seem to shift same (ie GOOD). Cold the Motul is nicer.

Key is frequent fluid changes!!

 

Thanks,

In thinking about the factory parts, I am not really sure what the hell Porsche was thinking. I guess they wanted to say that it had a limited slip diff but really did not want to do one that worked. I think the rebuild is going to be great, and I am sure it will be light years better. Glad I am finally doing this, it really is not as big a deal as I thought it would be.

 

How frequent do people change it? Over the last two summers I've got 12 track days in total on it and I'm a beginner, so I'd think I have a while to go.
Also, looks like the shop that put in my GT2 Pro used "Porsche OE 75/90 transaxle oil". Is Delvac OE?

 

I change mine every other oil change. I change oil every 4-6 track days. so if it were mine I’d change it. With an lsd the trans does get warmer.

im not tracking car really now so i just change all fluids annually.

delvsc is factory on the 997 cup cars it’s not the dealer stuff. You could ask them though.

 

Thanks, guess I'm due.

Transmission oil had not been on my radar so I read through some previous threads. Seems like OE is Mobilube PTX 75W90, and Delvac is a bit different and preferred for track usage, although may be balky when cold.
Millers (non-LS) CRX75W90NT also is talked of highly, and is about 2x more expensive than Delvac. Motul Gear 300 (non-LS) 75W90 is also mentioned favorably.

Hmmm, decisions decisions. I might go with the Motul Gear 300 since I already use Motul engine oil and it would be easier to remember. Or, maybe Millers. As long as I change it frequently it shouldn't matter too much.

 

All back together, I helped my mechanic pull the diff and disassemble but was not there for the new parts. Matt was very helpful, I know my guy has done a number of Guards diffs on his air cooled race cars but this was the first GT3 he had done, but it went smooth. A few notes from him. New friction plates are much beefier, as the photos in the in thread I linked show, and the preload cone washer provides much more preload. After talking with Matt, we used a small bottle of friction modifier for now, Matt suggests that we drain and replace the gear oil after my first track event, after that we can not use the friction modifier. Matt also recommended a short break in, going no more that 80% for the first couple of sessions, after that I am good to go.

Looking forward to the improvement, not a cheap way to go, but the stock parts were gone, I think I was pretty much at an open diff.