TheSamba.com :: View topic - Transmission gear oil recommendation

Sat Jan 12, 2013 4:43 pm

What is the recommended transmission gear oil to use in my 1958 644 transmission.

Sat Jan 12, 2013 4:49 pm

Swepco, it is more prone to weeping from any available opening, but that also makes it excellent at protecting your gearbox and making it function more smoothly. Pricey, but then how often do you change gear oil ?

Sat Jan 12, 2013 5:10 pm

356JAEGER wrote: Swepco, it is more prone to weeping from any available opening, but that also makes it excellent at protecting your gearbox and making it function more smoothly. Pricey, but then how often do you change gear oil ?

I see a Swepco 210 multigrade for Porsche gearboxes, is this the grade you are suggesting? I was amazed how "thin" the oil was that I dropped out.

For our 74 Saab Sonett we used a recommended Redline synthetic oil that we piced up at Summit racing, worked great. Almost looks like transmission fluid.

Sat Jan 12, 2013 9:49 pm

That would be the one...

http://www.allzim.com/acatalog/Transmission_Gear_Oil.html

Sat Jan 12, 2013 10:19 pm

SWEPCO 201 is great stuff for any Porsche manual trans, but tends to wick out of paper seals if they are not themselves sealed (permatex, hylomar, etc), making predictable measurements of preload difficult during rebuilding. I'm back to old-school hypoid gear oil.

Thin synthetics seem to like to find places to leak from that fossil lubes don't, trans and engine.

For the race cars in the last epoch, the 'hot trick' was to make the gallon needed from 2 quarts of hypoid (cheaper), a quart of ATF (to withstand pressure), and a quart of synthetic (a precursor of a 201 type lube and comparatively expensive, to give it coating 'stick' and permeation). A 'witches brew' sounded cool and worked fairly well.

Sun Jan 13, 2013 12:39 am

Kerry pointed out recently that it seem like 95% of the busted transmissions that we fix have Swepco in 'em. :o Just sayin'... We only use it on request.

Sun Jan 13, 2013 5:28 am

I still use the 90 grade Hypoid as well. In saying that, I have a confession to make, I always change my engine oil every 1500 miles. I have the date note in my service books telling me when I last changed the gearbox oil. I havn't looked at it in years and years. :?

I look at the suction filler I bought to re-fill the gearbox 40 years ago and think yes I will do it. But, the gearbox has no leaks in 44 years never touch wood been apart, is in operation perfect and as smooth as butter.

I realise, the gear train produces some metalic swarf over time and thats not good but.....

I would replace mine with SAE 90 hypoid next time I do it.

Roy

Sun Jan 13, 2013 7:26 am

Well, seems like the camp is about 50/50 here.

When I drained it last night there was a plug of sediment behind the drain. It washed out with the fluid. I took another tip to lift each side for about 30 min to get each axle to drain to the center.

What will I fill it with .......

Seems to be hard to shift into second. Fouth is also a little hard. I will have to work on the shifter adjustment (remember this is in the Beetle chassis).

Sun Jan 13, 2013 8:19 am

JeffL wrote: Well, seems like the camp is about 50/50 here.

When I drained it last night there was a plug of sediment behind the drain. It washed out with the fluid. I took another tip to lift each side for about 30 min to get each axle to drain to the center.

What will I fill it with .......

Seems to be hard to shift into second. Fouth is also a little hard. I will have to work on the shifter adjustment (remember this is in the Beetle chassis).

Unlike Jack, I have no trans mechanical "issues" that can be attributed to synthetics, but green puddles tend to become "customer satisfaction issues."
Thus, more problems equaling more money on both sides and no real noticeable improvement in street-driven shifting over 90W...the switch back was a "no-brainer" for the 356s that get MAYBE 500 miles/year, the average for my local customer base.
Yes, get the axles horizontal when draining and refilling so that when you see the side plug opening start to to drool, it's not overfilled.
The 2-4 shift issue sounds like an adjustment is in order first. I also teach many 356ers about double-clutching to lessen the symptoms even when adjustments are as good as can be.
Fill it with whatever or experiment. When testing an engine, I add 100LL avgas to 10% ethanol pump fuel to make a mix more like what the engines were designed to use. Maybe some synthetic gear lube mixed with 90w hypoid (see "witches brew," above, but modify) would be a compromise? Otherwise, I default to what Porsche specified.

Sun Jan 13, 2013 2:27 pm

^^^ I don't attribute trans mechanical issues with the use of synthetics, but I think some folks are hoping for "magic healing" of their trans' by using needlessly expensive oil.

Sun Jan 13, 2013 8:11 pm

Jeff,..My transmission had that same "plug" of sludge when I tried to drain it...very unnerving eh? The car had never been driven by me although I have owned it for 25 years or so. (I bought the car all in pieces.) The P/O said it drove and shifted fine though, but that sludge really bothered me, and since I didn't know the internal condition myself I decided to check it out. Pulled and split and I found that the diff carrier was cracked, and not just on the "short" side of the pin,..but starting on the big side as well. It was original, confirmed by casting date.

Soo,...I decided to correct that by buying a good used one from a noted rebuilder. He also agreed to set the big bearing pre load, pinion depth, and backlash on an a-la-carte basis. So the bare trans went to him with the gear cluster and intermediate plate. He did an outstanding job and provided me with not only a perfectly set up C/P but also expert analysis of the gear cluster and synchros.

When I got it back I decided to really learn exactly how these things work and I did learn a lot. The synchronizers work on friction. When you are selecting a gear the shift fork moves a toothed ring towards the chosen gear. That toothed gear interacts with a beveled ring (the synchronizer) and as it ramps up the bevel it slows the spinning gear down and stops it (hopefully) so the gears can mesh. Then the big gears are in drive.

What I have heard is that swepco can, at times,...in certain circumstances, actually provide too much friction reduction so that the (worn) synchro's can't provide the friction needed. That could be why Jack has noted that most of the transmissions that needed work had swepco in them. The owner was trying to "fix" a problem or worn out synchro's by using the magic bullet. Jack is right....there is no golden solution to a problem trans other than directly addressing the wear and the swepco being in there was likely a final hail mary.

All this being said,...I'll probably use a good traditional oil in my newly fixed trans. Other than the cracked diff housing, changed three bearings and the spider gears on a "good measure" basis...The synchro's, meshing gears, and drive gears were all good.

The trans is a 519 but the principles are the same regardless.

Fri Jan 18, 2013 9:05 am

I'd recommend Swepco 201 for all pre-'87 Porsche transaxles in street cars. It is the ultimate dino gear lube (NOT a synthetic like some seem to believe), and was specifically developed for Porsche to solve premature wear of the 935 R&P. (All pre-'87 use virtually the same type of synchro. Stay away from the moly versions of Swepco which don't work well with early syncros, and avoid synthetics.)

To this day, Swepco 201 provides superior EP protection over long term than most synthetic gear lubes (many of which aren't even meant for R&P). Some highly respected shops even use Swepco in place of Porsche recommended synthetics in late model transaxles (GT3 etc) because they desire the superior EP additive package. JMHO

Fri Jan 18, 2013 4:27 pm

gears wrote: I'd recommend Swepco 201 for all pre-'87 Porsche transaxles in street cars. It is the ultimate dino gear lube (NOT a synthetic like some seem to believe), and was specifically developed for Porsche to solve premature wear of the 935 R&P. (All pre-'87 use virtually the same type of synchro. Stay away from the moly versions of Swepco which don't work well with early syncros, and avoid synthetics.)

To this day, Swepco 201 provides superior EP protection over long term than most synthetic gear lubes (many of which aren't even meant for R&P). Some highly respected shops even use Swepco in place of Porsche recommended synthetics in late model transaxles (GT3 etc) because they desire the superior EP additive package. JMHO

Let me begin with "respectfully".....In the never-ending quest for "learning something new every day"...just what is added to make 201 the "ultimate dino gear lube" and NOT a synthetic as yes, I was led to believe. South West E-something Petroleum Co. was chosen by Porsche to specifically develop a special lube for 935s? Impressive...unless one is stuck in the 356 era and has heard of but does not know anything about a GT-3.

Yes, I am personally chemistry challenged.....I only passed that course in high school because teach made a bet I wouldn't score 20 in a big b-ball game, and I did, so I passed...so please make the explanation in terms even a mechanic can understand, TIA.

Fri Jan 18, 2013 4:50 pm

Bruce,
Swepco 201 is primarily make up of paraffinic based dino oil and has synthetic additives, like most oils. True synthetics have no dino components.

Fri Jan 18, 2013 6:44 pm

For the cars we are concerned with in this, 356 Porsche's, all of the fancy
oils out now, will not address wear and tear on the moving parts. That is
to fix a problem. Oils will not repair worn parts, and will not address shift linkage problems.
When in doubt use what owners manual direct you to use. All the years
with VW and Porsche we always used Hypoid 90Wt of a good brand.
Thats just my opinion.

fcampbell356

Fri Jan 18, 2013 7:40 pm

Wasn't the actual Porsche recommendation 80 wt hypoid oil? It seems trans oil is something that folks like to play with...I recall back in the day using 40 wt Castrol R racing oil in the trans was supposed to be the hot trick. That said I also use Swepco in my '59 and currently have 90 wt hypoid in my '53.
Alan

Sat Jan 19, 2013 5:47 am

Are you guys looking for some kind of performance upgrade? Like smoother/better/easier shifting, less friction? Or is it mainly for longevity/less wear? If the latter I don't think it really matters because most would be lucky to see 50,000 miles in the next 20 years.

I am far from an expert on these cars but I will run whatever the manual says & not worry about it.

Sat Jan 19, 2013 7:17 am

Mic,

I agree with you. It would be nice to know though on an average just how many miles we all tend to drive per annum. If your gearbox is and has been always working well with SAE 90 hypoid why change?

Its the same as engine oil, I used 30 grade Shell Rotella for years then that changed to Shell S Rotella, now its Rotella T I think? As it became harder to get locally I changed to a multigrade. For so many years Porsche said no to that, it seems that decision changed some years ago.

Years ago I used to put a squirt of Redex in the fuel, never seen Redex upper cylinder lubrication for many years now. When I was riding my bikes, a friend put about 15 squirts of Redex in the BSA Goldstar fuel tank and said it would give him a cheap 'decoke' It encased the petrol station in blue smoke but with the copious amount of 'Castrol R' engine oil he was already burning, the petrol station did have the most wonderful smell. :lol:

Deviation sorry.

Roy

Sat Jan 19, 2013 4:42 pm

Alan, 80wt for colder climates and 90wt for warmer climates.
And on rare times we used MoS2 from Lubro Moly on times when hard
shifting was experienced. In some cases it helped, but others it did not.

fcampbell356

Sat Jan 19, 2013 9:47 pm

I too am in the "classic" oils corner, gearboxes, engines and strng. box, all. 90w in the box year round works fine here in the Lake Effect Snow region; just give it a chance to warm up before asking anything sudden. But then, I'm a life-long habitual double-clutcher. Down and frequently up, especially when the box is cold.

I've always used a 20w 50 in the engine with good result, but maybe that's just me. I flirt with 10w 40 sometimes in the winter, but oil pressure at slow idle doesn't like it as well in a well-warmed engine.

And if a soapbox were handy, I would opine that the majority of wear issues emanate from an insensitive shift lever and a clumsy clutch. Believe it or not, a clutch disc can last the life of the car, when treated nicely.

But I digress.