901 and synthetic oil

84 IM Flier · 09-13-2003, 09:40 AM

I've put synthetic oil in my 901 and I'm not sure if I should exchange it for something like Swepco 201. Some people have told me that I should not run sythetic in a 901, while others have said that sythetic would work just fine. I've tried a search, but I guess I'm not putting in the correct 'search' words. I'm new to the forum and new to Porsches, so any advice would be appreciated.
Ron

ChrisBennet · ChrisBennet's Garage

The 901-915 transmission synchros apparently prefer something less slippery than synthetics. Swepco 201 being the most common preference.
-Chris

jgparker · jgparker's Garage

I switched to Mobil 1 70W90 in my 901 a while back, and I have notice that the syncros do not bite as well as with conventional oils.

TimT · 09-13-2003, 03:18 PM

I use mobil 1 in my 914, and 911 gearboxes.....no problems at all.

84 IM Flier · 09-14-2003, 11:14 AM

I finally figured out the search. Put in Synthetic, transmission, Swepco. Got TONS of posts and a lot of very good information.
Ron

jluetjen · jluetjen's Garage

I had mobil one in my 901 box and the syncro's definitely seemed to be on their way out. I put Swepco in and they improved quite a bit. They'll still need replacement one day, but the Swepco definitely made them happier.

Tim, were your boxes freshly rebuilt or did they have a lot of miles on them?

TimT · 04:41 PM

John,my boxes were rebuilt with the best used parts I could find
(out of the 5 or so trannies I have as donors). I replaced the 234 synchros in the 901 box, in the the 914 box I reused the old syncros..

Alot of shift problems can be attributed to worn bushings, a sloppy shift coupler and poor adjustment (or adjusting to make up for worn components).... With properly adjusted shift forks, fresh bushings, a apex type coupler, and a "Rennshift" my 914 shifts like it is gated... very positive... partially worn syncros and mobil 1 not withstanding

red-beard · red-beard's Garage

Oh GOD! Not another one of these.

I refused to get sucked in again....

James

jluetjen · jluetjen's Garage

What's with him??? Crawl out of the wrong side of bed this morning Red'?

red-beard · red-beard's Garage

Oh - we just had this discussion last week on the 911 Board.

It's a he said she said thing. No one has any data and people keep chiming in that Swepco is the best thing since sliced bread. Their website doesn't do anything to validate or disprove the wild claims about They leave nothing to be verified to disproved.

To me, the Swepco thing is pure marketing.

The website describes 201 as highly refined petroleum oil. Nothing more or less.

It's double the cost of Mobil 1 and it's about 6 times the cost of Coastal 85W-90

And no one likes to hear the emperor has no clothes. It cost more, has a cool name and is blue in color and Joe over there used it and he said his car shifts great. Therefore it has to be better.

Did I get it about right guys?

James

Dammit - sucked in again

tops911 · 09-15-2003, 01:30 PM

In Bruce Andersons book he made a strong reccomendation for it. I think in the 935 race cars there was premature wear on theR&P after a change to Swepco they did not have the problem.

red-beard · red-beard's Garage

That may be true. BUT, that is apples and oranges. Synchros and R&P have 2 completely different functions and 2 different sets of needs and operational characteristics. . And I'd guess he's using 212 not 201.

You're just trying to get me going...aren't you... Well it won't work

James

jluetjen · jluetjen's Garage

Quote:

You're just trying to get me going...aren't you... Well it won't work

Absolutely not Red'. It never occurred to me until you brought it up...

TimT · 09-15-2003, 04:50 PM

I thought this post was about using synths in a 901. NOT about comparing synths vs dino. In real world track driving the 901 with mobil 1 works just fine (for me)

red-beard · red-beard's Garage

Jake Raby - Top notch Type IV rebuilder - has Dyno data comparing synthetic to Dino. Running synthetic puts more HP on the road. It's the only realy data I've seen.

Plus - you are much less likely to over heat synthetic. I use Mobil 1.

James

84 IM Flier · 09-15-2003, 07:34 PM

Well, I'm leaving the synthetic in. Shifts fine...no leaks (yet).
Ron

Wayne 962 · Wayne 962's Garage

Without emperical data in hand, many, many, many of our customers proclaim less or no grinding on an old transmission after switching to the Swepco. While this *could* be the placebo effect, I believe that there are enough nay-sayers out there who would step up and dispute this. So far, there have been very few.

Synthetic = more slippery = less friction = less loss = more HP to the wheels. Common sense there.

However, the synchros in the transmission (different story) require friction to work and spin up the gears as you're shifting. Too slippery = gears not matching = grinding when shifting.

Seems to me like the synthetic / dino argument would be like trading one thing for another...

-Wayne