I've used this stuff before in other cars and have been impressed. Anybody running this? Is it a good fit for the 901 transaxle?

Do a search here, this has been discussed ad nauseum. The general consensus is that the older Porsche transmissions, including the 901, have syncros that need more friction to work properly and modern synthetic oils just can't provide that.

Any good ole dino oil should do. Personally, i like Swepco 201.

And be prepared for some heated comments here shortly, since talking oil is right up there with religion, politics and the /6 vs. /4 debates.

Thanks for the input. That sort of mirrors my philosophy for engine oil....good quality dino, change it often.

What Andy said, eveyone is a zealot. My preference is Motul FF-LSD synthetic.

Yes! Doing my best to stay away from the "Originality and History" section...some nasty fights there.

+1

Once you go Swepco 201 you never go back

Two things...

1. You will have a few people on this forum who will come out of the woodwork who will swear by MT 90 in the 901. It can quickly turn into a flame war.

But... RedLine MT 90 is not GL-5 spec and if you look at their own literature, they don't recommend using it on transaxles with hypoid gears such as the Porsche 901. If you are set on using something from RedLine then look at their "75W90 NS" product. Here is the product page for it...

http://www.redlineoil.com/product.aspx?pid=47&pcid=7

If you read the info on that page, you will see they hit the high points regarding GL-5 for our hypoid R&P gears, proper friction modifiers for synchros, etc. You can find mention further down about not using MT 90 in our application.

2. It is a synthetic. They tend to be a bit more slippery than traditional mineral/dino lubricants. So they probably work great with modern Borg Warner synchro design, but not as good with the older Porsche synchro design that requires decent friction to work right.

As always your mileage may vary. I personally wouldn't be afraid of giving their 75W90 NS product at try as maybe they got the balance right between synthetic slipperiness and their friction modifier package. I personally would absolutely not use MT 90 however.

If you care to read it, I have this article on my website about lubricants...

Transmission Lubrication


Richard

redline did wonders in my 901 tranny, it was the stuff specific for this tranny, but redline has changed the name since then. tranny was diffuclt to shift, and thought to be shot, switched to redline and 70,000 miles later still good. I have it in several of my air cooled cars.

I killed two first gears using Redline MTL. The dogs just stripped off because the gear did not slow down enough, ie too slippery. I now use a good cheap 90w