Moly vs. not...Gear oil question
 

Ok, I just got off the phone with a Porsche mechanic with a good reputation. I've been having some problems with my tranny and crunching 1st and 2nd gears. Changed my gear oil (using Valvoline 85W-140 temporarily), waiting a week or so before putting in the good stuff. He said that putting in the moly gear oil could really cause problems with my tranny. Right now it occasionally crunches first gear (getting better tho since gear oil change) and ocassionally crunches 2nd (also getting better). The mechanic seems to think that putting in the moly gear oil will cause it to grind even more.

Does this make sense? Anybody have an opinion on this!?

I hesitate to ask, but, what is "moly gear oil"? Is this a brand or type or synthetic or ?

Jerry M
'78 SC

It's made by Swepco; here it is on Pelican:
http://www.pelicanparts.com/cgi-bin/autocat/load_page.cgi?page_number=4&bookmark=0&model=DWKS& currsection=swepco

It was recommended to me in this thread:
http://forums.pelicanparts.com/porsche-911-technical-forum/102485-vrooommm-shift-crunch-ugh.html

Please, any information would be very helpful, thanks!

I'm pretty sure the thread was recommending the Swepco 201, not the moly gear lube. 201 is what I run and is what almost every 911 person I know recommends for the 915.

Aaah, now I see, someone recommended Swepco 212 "Moly Multi-Grade Gear Lube ". I have no experience with 212, I've been using 201 (which is the recommended weight, BTW). I see they also recommended adding "moly" ("Molybdenum Disulfide", which most gear lubes have and which gives added scuff protection to heavily loaded gear teeth and such) if you use some other brand of lube. My concerns with 212 is it's the wrong weight and it may provide the wrong coefficient of friction/lubrication, not allowing the synchros to work properly. I've been satisfied with Swepco 201 so I don't feel the need to experiment. If you've seen some improvement with Valvoline, maybe it's time to try 201.

Jerry M
'78 SC

I believe there is also a brand name gear oil called Moly something or other also. I don't believe I have ever heard anyone complain about Swepco making the tranny worse or causing grinding. I've heard a number of people complain about the fact they heard such good things about Swepco, spent the money and saw no difference. Swepco does make different mixes of gear oil, 201, 210, 212.

Dan O

The moly version may not allow the baulk ring style of synchronizer to work properly, and cause even more grinding during shifts.

Ok, that's similar to what the mechanic said, but Warren Hall (aka Early_S_Man) says that he uses the stuff and it's really helped his tranny alot. I've ordered the stuff and I'm not sure if I should use it now.... :(

Sounds like a cheap experiment for possible real benefits. Go for it, and please share your impressions --

I use a product by Dow Corning called Molykote M Gear oil additive. It's an incredible industrial moly additive added to the gear oil of any machinery to triple+ the galling resistance and shear strength properties of gear oil to extend the life of gearboxes and machinery. 11% fine black moly powder is suspended in mineral oil, and is to be added to you existing gear oil anywhere from 3-10% by volume - of course the more you add the greater the protection. It worked especially well in the gearbox of my heavily modified SAAB Turbo which consistently sheared off the teeth of third gear from extreme torque, and its magnetic plug would always catch fine fragments of steel without the use of Molykote. After the addition of it, it virtually eliminated any further accumulation of metal fragments to the magnetic plug, and a burning smell of the gear oil from extreme heat. I did not notice any negative effect to the brass synchros of the tranny. I currently use 10% by volume Molykote mixed with Redline 75-90 synthetic gear oil in my 915 tranny without problems. It will turn your gear oil a graphite grey and coat every single part of your tranny's guts with black moly. Molykote's data sheets are quite spectacular to read. Check it out if you want.

http://www.dowcorning.com/applications/Product_Finder/PF_details.asp?l1=003&prod=01005855&type=PROD&pg=0 0001040

Here's a 360k pdf file to download:
Dow Corning Molykote M PDF sheets

Great info Steve. That seems to be in line with what Warren Hall said also. When I've talked with other gear heads about this, I kinda get this blank look like they have no idea what I'm talking about. You've also answered another question I had, without even knowing it! I wanted to know if you could just add an "additive" to your existing gear oil.

Ok, now all you need to do is tell me where you buy the additive! Thanks Steve!

I'm changing the mystery gear oil that's in there now for 212 this weekend. Not that my screaming 140HP is putting much stress on the gears, but I'm interested how it will affect the feel.

It is amazing how online testimonials sell products. I wonder if Early_S_Man gets a commission? Oops--then it would be Amsoil. :rolleyes:

Jon, I'm doing the same thing this weekend in preparation for an autox NEXT weekend. I'll keep everyone posted as how the gear oil works in the tranny. I'm sure other people would be interested in whether this stuff can at least help an ailing 915 :)

I don't remember the name of the place I puchased it from. I purchased it from a large Dow Corning distributor in Burbank, CA that specializes in industrial additives, coatings, and lubricants. I believe they ship. May want to check with a local distributor in Colorado via the link the have on their website.

Matt,

I'd just stick with the Swepco product line if it were me. They already have the Moly in their gear lube, premixed and nothing extra to do. That's what I'm running in mine.

Dan O
84' 3.2 Targa

VW used to sell Moly trans oil additive in a snip & squeeze tube. But the VW has Borg Warner style synchros, like the G50 & later.

Yes, the Molykote M gear oil additive is what I used to add to Valvoline SAE 90 and SAE 140 gear oil, and it worked great in my 915 for years before I started using the Swepco 201 SAE 90 gear oil -- not the blue SAE 80W-90.

Bruce Anderson had such good luck with Swepco 201 at Le Mans and a few other tracks ... that the lifespan of a 935 ring & pinion was extended from about 40 hours to an entire season of racing!!! It really ISN'T just another plain gear oil like someone recently suggested in another thread!

The Swepco 212 seems to be ideal for hotter climates where summer temps exceed 100 ... and our 915's run no coolers, and hence, unbelieveable gear oil temps!

Well, I received my Swepco 212 gear oil on Friday and installed it that evening. Again, to get my tranny level, I removed both back wheels and lowered the car until the calipers were about an inch from the ground (wish I had a lift). Since I put in this gear oil, I have not had to "force" my tranny into first, and it also gets into second gear easier too. If you're interested in the short history of my tranny problems, you can find that thread in one of the links above. I just have to tell you, it is a completely different tranny with this stuff in it. A mechanic said the gear oil would make it grind more and might not even work the synchro correctly, but in my case (and others who have contributed to this thread) he's dead wrong. Not only does it work, but it works great. If your tranny is grinding a bit or a little tough getting into gear at times, dont hesitate and just put this stuff in. I'm not going to say it's the cure all, but man I'm sooooo MUCH happer with my transmission now! I'd recommend this to anybody who asked...

Warren Hall (aka Early_S_Man), if you're ever in Denver, I owe you a brew http://www.pelicanparts.com/support/...s/beerchug.gif

Just another data point here.....
I used a bottle of MolySlip in my 915 when I first got my SC.
I'm sure it did help with shifting. But since the idiot at the lever has actually learned how to shift the thing, regular Swepco w/o moly works just fine.

Hmmm, well...you tell me. If I'm sitting at a red light with the car in neutral and the light turns green. I push in the clutch and gently push the car into 1st gear and it wont go. Now I try to put the car into second gear and sometimes it goes into second, sometimes not. Then I go back to first...still nothing. Even with a fresh change of Valvoline, I still had the problems. Now I put Swepco 212 into my tranny and it now goes into first gear EVERY time easily from neutral. I'd say that it's worth the extra $5.

I guess you could save the $5 and just go with the regular Swepco, but my question would be: "why". You shouldnt have to learn how to drive a 915 differently, it should just work. Neutral to 1st or 2nd gear is nothing special...nothing at all.

Take away from this whay you want, I'm just saying it made a very big difference over a fresh change of Valvoline (which is NOT crap gear oil) in my car. Wouldnt you spend an extra $5 for a multi-viscosity gear oil with the moly added? Tell you what, I'll pay it forever now...