I am doing the engine oil this weekend. While I am down there, maybe I should just do the transmission fluid as well. What are the recommendations for transmission fluid? What make and anything I should be worried about?

Thanks
-Gary A

 

There was a thread on this not long ago. I use Motorex Prisma ZX 75W90 with good results.

see this thread https://rennlist.com/forums/993-forum/157436-gearbox-oil-grinding-transmission.html

 

There's lots out there: Redline, Swepco, Mobil, etc. The manual states minimum ratings which you should abide by (GL5, I think??). I use the Mobil 75w/90 synthetic with good results when cold or hot. Plus it's easy to find at most any auto parts store. For more opinions, you can try the archives for people's feedback on the different oils they've used.

Edward

 

I just put in 3qts Royal Purple synthetic and 1qt Mobil1 synth, both 75W-90, and I AM NOT a happy camper. Saturday was about 70F outside and my first shift from 1st to 2nd resulted in a grinding sound (like the first shift on an ice-cold winter morning). Apparently the synchros didn't like the higher viscosity due to the newness and the Royal Purple. If it ever does it again I'm probably going to have to replace it. Grrrr.

 

Lots of opinions if you do a search.

I switched back to Mobil 1. I still get a grind going into 2nd gear when not warmed up, unless I pause in neutral or go really slow.

 

If you have new oil and your clutch is adjusted and the car still grinds, then I would think your synchros need replacement.

No?

 

i just filled up with redline. so far seems just like mobile 1.

 

Be careful to stick with higher quality gear oil since it also lubricates the ring and pinion (and LSD if so equipped). These gearbox's do get quite hot, especially in a track setting.. I personally stick with Mobil 1 synthetic..

 

i tried redline and i don't recommend it. it was really noisy compared to mobil 1. i switched back to mobil1.

cheers,
boris

 

If you have an LSD in your transmission don't forget to add 1 pint of Chevrolet LSD fluid.

 

We used to use this stuff in our Ford 9" rearends as it is a friction modifyer that takes some of the clutch-pack chatter out of the rear end. I have not heard of this being used in Porsche transmissions. I myself dont as I am afraid of this friction modifyer effecting syncro operation. They need all the grip then can get

 

Chris,
I just noticed...GREAT avatar!!!
...true HWFM fashion

Edward

 

Yes, in true HWFMR fashion, thanks to mnmblu...

 

Jason - Mobil 1 has friction modifyers already included, so it works very well with limited slips.... Gosh, I used the Chevy stuff for YEARS when I was into small block Chevy's and Pontiacs.. To show you how far I go back, the pint bottle of the stuff use to be made from whale oil (at about $9 a bottle in the late 70's).. Then they figured out the synthetic stuff....

 

LOL, I thought I was the only one who paid that for a small bottle of, what was rumored to be, whale sp*rm

Funny thing as I had a buddy who added this stuff to his diff oil when he had a Detroit Locker installed. No clutch plates in there