I was wondering about putting Mobil 1 synthetic gear oil in the 914 trans but my mechanic mentioned that sometimes it is too slick and not enough friction in that the gears, from what I understood, don't slow down enough and causes problems.
I had used El Cheapo Co-op synthetic in my Jetta, but last week put in the Mobil 1 and what a improvement in the shifting even in it. So I was just wondering what type of difference it would make if I was to put it in the 914 trans?

Synth don't work in your 901 trans. Many have tried. Many have failed.
That goes for Redline MTL synth as well.

Your 914 trans has a much different synchro arrangement than a Jetta.
(or dam near any other manual trans for that matter.)

Use the Swepco 201 oil. You and your trans will be happier for it.

C

I tried it, bad idea. Stick with Swepco.

I use it exclusively in race only applications
but more for heat really...

brant

I've always had synthetic in mine and never had any problems. My 914 gets drivin all over the States and works perfectly. Here's a link to what I use.

http://www.amsoil.com/StoreFront/agl.aspx

I've asked an highschool buddy of mine that is a 'Porsche Master Tech' for the past 30+ yeas and his response was try some.. so I ended up using a 50/50 mix of Swepco and Mobil 1... I also had a 2nd gear issue with my 83 320i BMW - ended up putting Mobil 1 and shifting was a little easier....Just my 02cents

First let me say that the syncro setup in 901/915's do require more friction than the newer transmissions. It is said that synthetics are too slippery. If you are having any trouble with shifting due to a worn out box, I would not use synthetic.

Now with all that said, I use Mobil 1 in both my 911 and 914 (915 in both). They shift like butter. I should say that before switching, I rebuilt my trannies along with fresh clutches and cables. I'm not a "bang-shifter" either.

I think if you are not pushing your tranny hard by shifting too fast and your tranny and clutch are in good shape you will enjoy much smoother shifting with synthetic. You will notice an immediate difference if your box is fresh since they shift very firm when new.

Between the Rennshift and the synthetic it "almost" feels like a modern tranny.

Others will scorn this but it works great for me.......

Jake uses Synthetic. I use Synthetic, but only after the 1st change. I hate wasting synthetic if I have a leak.

I second that, I have been running Amsoil in my 914s for over 20 years and have never had a problem, and it makes it shift real smooth.

I probably should have stated that you should break them in on dino before filling with synthetic. I posted a break in procedure on the bird board
915 break-in

Motul FF-LSD works really well, and is suitable for clutch style LSD. Shifts as well if not better than dino.

Swepco 201 for 901, 915.

Mobilube SHC (now Delvac 1) for G50 and later.