901 Tranny gear oil

[copper]

Gonna be replacing the tranny fluid when I get her pulled down for the clutch replacement.

Wayne recommends the Swepco 201 Gear Oil for replacement. I am having difficulty finding it here in Ontario Canada.

Can anyone recommend a gear oil that would be as good (or close) as the Swepco in terms of lubrication and extension of the life of the synchros etc? I see that there are lots of synthetic options, in good names like Mobil 1, which is what I use in the engine. (No, not gear oil, Mobil 1 full synthetic motor oil)

Or, do any Ontario Pelicanheads know where to find Swepco locally?

Thanks
Jim

[KobaltBlau]

I did a bunch of research and decided that of the majors, Pennzoil non-synthetic was a nice gear oil, specifically the 80w-90 GL-5. I just yesterday saw some Mystic 80w-90 for 2.50/qt which is an even nicer dino based gear oil than the Pennzoil and very cheap. It is made by Citgo. The Mystic is marketed almost exclusively to the farm equipment/big rig market. There are a few other oils that fall into this category as well. I think your best options would be to find some Pennzoil or head to a farm or big rig supplier and see what you can find. You might have to buy a 5 gallon bucket but they aren't that expensive. You could post here what you find and I could give you some feedback. I can also provide more detail on why I thought pennzoil was a good choice as well.

People have reported success using Valvoline on this board, but I don't think it's a particularly good gear oil. Both 80w-90 and 85w-140 have been used by people with 915s (almost the same application really), but I wouldn't recommend 85w-140 weight in general unless you are in a hot climate and/or doing heavy DE or racing.

Here's an important question for you: What is the lowest temperature you drive the car in regularly?

[Zeke]

Jim, did you try the Swepo site? They told me about a stocking dealer/distributor here locally. (I still get it from Pelican).

Also, doesn't Redline Oils make a decent gear oil? You should be able to get that nearby.

[TimT]

I have a few cases of swepco prods... I could send you some.

[KobaltBlau]

In addition to the potentially hard to find Mystik, Chevron Delo 80w-90 is another high quality non-synthetic gear oil that you should be able to get. They also tend to go after the "Diesel" market.

However, there is an important difference between the Delo and the Mystic. The Mystik is suitable for "Service fill" of limited slip axles, where the Delo is suitable only for "Top-up" of limited slip axles. This means that you may need to add some limited slip friction modifer to Delo. This is easy to find, there is even a ford version, but you should not add more than .5%, half a percent, according to an expert I talked to. The danger is with the porsche balk ring synchros in a 901 or 915 box that too much friction modifer prevents the synchros from working well because they don't have enough friction. Another alternative is to add 10% dow corning molykote M, like steve W does on this board. He uses it with a Redline 75w-90ns synthetic, which does not have a friction modifier. I think the moly may help his LSD not chatter.

If I were you I would probably find the Chevron Delo 80w-90, put it in, and if your limited slip chatters (if you even have one) add .5% friction modifer. If you don't have a limited slip, then all you have to do is get some Delo.

Best Regards,

[KobaltBlau]

The Mack GO-J and GO-J Plus standards seem to select some of the better quality gear oils. You'll notice that Delo is one of the only non-synthetics to make it onto the GO-J Plus list:

GO-J Plus: http://www.macktrucks.com/assets/mack/approvedlubs/Mack_Trucks_Approved_GO-J_Plus_List.pdf

GO-J: http://www.macktrucks.com/assets/mack/approvedlubs/Mack_Trucks_Approved_GO-J_List.pdf

If you drive the car in very cold weather (see the question I asked above), I would consider the following:

If you don't have a limited slip diff: Red Line 75w-90ns
If you do: Red Line 75w-90ns with 10% Dow Corning Molykote M, as Steve W uses. The problem here is that you'd more than likely have to get the Molykote by mail, it comes in a quart. The other alternative is to try the 75w-90ns with no friction modifer, then add .5% if your limited slip chatters. a little bottle of friction modifer should be no problem to find. You have none of these problems if you don't have a multiplate clutch limited slip differential.

Over the counter Mobil 1 gear oil is not very good. I personally would steer clear of synthetic based gear oils that already contain an unknown amount of friction modifier. The red line oils ending with "ns" do not contain any friction modifier, nor does mobil 1 SHC, available only in 5 gallon buckets or bigger in the US.

[copper]

On doing more research, I did read about the use of or rather the recommendation of not to use synthetics or semisynthetics in the manual tranny.

On another discussion board, they talked about the Redline products.

The daytime is still around 20 degrees here. (72F). The nights get to about 12 (56F). It'll be going away soon. The coldest I can see getting caught driving, if the temps really dropped at night, is about 5 (42F). But that would be right at the end of the limit.

Zeke:

I checked the site. No list of distributors... I will call then on Tuesday.

Tim T:

Thanks. Trying to find someplace local to avoid having to ship it into Canada.

KobaltBlau

I'm slowly becoming more mechanically inclined. Not sure if I have a limited slip diff, or not. Don't really know the difference. What is stock for a 69 911T ?


Thanks
Jim

[911SCcdn]

Hey Jim,

Not sure if this helps...

Here in Ottawa..I get Swepco from a local shop specializing in Porsche (and others).

Shop is Autoimport. .... www.autoimport.ca

Andy
81 911SC
70 911T

[KobaltBlau]

Originally posted by copper
On doing more research, I did read about the use of or rather the recommendation of not to use synthetics or semisynthetics in the manual tranny.

On another discussion board, they talked about the Redline products.

The daytime is still around 20 degrees here. (72F). The nights get to about 12 (56F). It'll be going away soon. The coldest I can see getting caught driving, if the temps really dropped at night, is about 5 (42F). But that would be right at the end of the limit.

I personally believe that synthetics could be used just fine with careful selection. However, based on your temperature ranges I see no reason to worry about that, you should be able to use non-synthetics just fine.

Originally posted by copper

KobaltBlau

I'm slowly becoming more mechanically inclined. Not sure if I have a limited slip diff, or not. Don't really know the difference. What is stock for a 69 911T ?


Thanks
Jim

I think it's pretty unlikely that you have a limited slip differential, unless you have several 'S' options on your 'T'. Here's a good way to tell: Jack up the back of your car under the engine, as wayne explains in his 101 projects book.

then, with the car in gear, turn one of the rear wheels forward. If you have a multiplate clutch (factory type) limited slip differential, which is the kind that you have to worry about gear oil with, and it isn't worn out, the other wheel will turn the same direction. Otherwise, the other wheel will turn the opposite direction.

My guess is if you do this test the other wheel will turn the opposite direction. If for some reason after changing the gear oil you get a little grabbing when turning away from a stop, such as turning right at a stop sign, you'll know that you actually have a limited slip and it is 'chattering' a bit.

I know a lot of people here and elsewhere feel that SWEPCO is the only way to go, but if I were in your situation, I would try to buy Chevron Texaco Delo GL-5 gear oil in the 80w-90 weight. Again, this is a very high quality non-synthetic that you are most likely to find in diesel oriented shops, such as farm or OTR (trucker) supply. I have seen Delo motor oils (in gallon bottles) at my FLAPS (friendly local auto parts store, such as checker/kragen, napa, etc), but I don't think I've seen gear oil there. Mystik, Shell Spirax, and Pennzoil GearPlus are other alternatives, with quality probably in listed order. I'd get the Delo if I could. Even if you had to have a truck shop order it it'd still be _massively_ cheaper than SWEPCO, and it's very very good stuff. In any case, be sure you get GL-5, and 80w-90.

Let me know if you have any other questions!!

[copper]

Thanks folks!!

I will check my local NAPA and see what they have/can get.

Jim