901 transaxle gear oil

[1QuickS]

My box has 100k miles and although the synchros are OK it would be nice to get as much life out of them as possible.

I have heard good things about Redline MT-90 gearbox oil.

Any comments regarding this lube or alternates?

[sanders]

Redline shock proof heavy in my race cars and street cars. Seems to protect even the pinion gear.

[catelluseng]

Redline shock proof heavy in my race cars and street cars. Seems to protect even the pinion gear.

Pinion from a 944-series transmission in the shop right now, was run with Redline Shockproof according to the customer. ymmv.

[1QuickS]

I asked a venerable gearbox/engine builder who posts on this site and he said he uses 75W90 conventional oil, not synthetic.

[66S]

Because Porsche synchros need friction to work properly.

[xpensivewino]

I was also told by a Porsche gear box expert to only run conventional Dino oil, as you mentioned 75/90

[Chuck Miller]

Because Porsche synchros need friction to work properly.

About 30 years ago I found that the last three posts were very true...first hand

I had a crunchy 915 box and read somewhere that a full synthetic would fix it ....
Went to a motorcycle shop and got some VERY expensive synthetic gear oil (Redline I think)

Old out, new in, and could hardly shift the car at all ....

In went dino again ... and the 915 was eventually rebuilt...

... and so it goes

[RSTarga]

I got 145,000Mi out of my box running Swepco 201, so I guess it's a good oil.

[TheBrownCar]

Hey Paul,
We also use Swepco 201 here at the shop and have had great success for many years. We love it. Hope you are enjoying having your car back!

Clay

[sithot]

Kendall is fine as well.

Tom

PS: I think if you go over to Pelican you can find endless debates (if you're bored).