transmission oil , mobil 1?

I had been using LAT full synthetic 90 wt oil (similar to the Mobil 1 transmission oil) from Rancho on my freshly rebuilt VW transaxle, but found it to be somewhat noisy.  I flushed it out and replaced it with Valvoline blended 90 wt Hypoid oil.  The gearbox quieted down quite a bit, although it now shifts somewhat stiffer until it warms up (mostly noticeble trying to get into first while moving).  

Porsche has been recommending Mobil 1 gearbox oil for decades, so I wouldn't be afraid of using it.  Just be mindful of any gearbox noise you might experience and decide from there.

Thanks Gordon.

I dunno, i remember reading that the GL classification is important, im thinking u cant use GL5 in a VW tranny as it attacks the  bronze synchros?

bronze , brass, copper, dont know which but they call them yellow metals..

I have used redline full syn in non vw application and subaru and find dyno oil to be quieter

The guy that rebuilt my transaxle, Mike Gagnier, said not to use synthetic as it tends to be too slick to allow the synchros to work properly. He s a lot more knowledgeable than I am about this stuff but then a lot of you guys are using it with no problem. Mine is a little stiff when cold downshifting to first. The old was was too til it warmed up.  So even with the non synthetic the synchros still don't work great when cold.  I don't know if it really matters.  I think you can probably use whatever you want.

The last 911 I had was a 1996 993 . And it had a stiff second gear. That crowd has a lot to say about trans oil. I tried several different types and in the end it was the "slave" cylinder was going bad. (Hydrolic pedal , this is the small secondary pump on the bell housing.) It took quite a bit of magic to replace it. Almost impossible, until I finally saw the little , covered in grease, rubber access grommet on the side of the bell housing.  Live and learn and learn and learn...

barncobob posted:

I dunno, i remember reading that the GL classification is important, im thinking u cant use GL5 in a VW tranny as it attacks the  bronze synchros?

Apparently, the early API GL5 spec has high concentrations of Sulpher Phosphorus additive which was used to make the fluid more squishable between the gears. The belief was that it causes the yellow metals to get brittle.  Napa supposedly carries Sta-Lube GL4 but you won't find it a big box stores.   

Now I am a bit confused.
Is gl5 and gl4 the base for mobil 1? Or is mobil 1 unique unto itself... and gl5 unique to API? In that case I will just stick with Quakerstate gl 80/90 and play it safe.

There's a 56 (at last count) page thread on TheSamba on gear lube. Let's just say that some folks really need to get a life.

All I know is that GL4 if older than GL5 duh... 

And there are full synthetic, semi synthetic and Dyno...  I have tried full synthetic and it's good in the winter but I felt it was always a bit noisy and notchy shifting when warm.  Full Dyno is quieter albeit stiff on start up till warm.  

Have yet to try semi synthetic but it might be worth a try.  Last time I bought a wack of gear oil and I have much left over so it might never happen not to mention it is quite an accrobatic feat to change tranny oil without a pump.

Right ; Stan! :-)

WOLFGANG posted:

barncobob posted:

I dunno, i remember reading that the GL classification is important, im thinking u cant use GL5 in a VW tranny as it attacks the  bronze synchros?

Apparently, the early API GL5 spec has high concentrations of Sulpher Phosphorus additive which was used to make the fluid more squishable between the gears. The belief was that it causes the yellow metals to get brittle.  Napa supposedly carries Sta-Lube GL4 but you won't find it a big box stores.   

The GL is for gear lube and the sulphur and phosphorus additives are to resist galling under high pressure. That's why all the flat tappet cams were wearing out cam lobes after the oil companies removed the high pressure additives because they were bad for catalytic converters.  Modern cars don't need the additives because they all have roller follower cams. So now we get to buy $69/case Brad Penn or Joe Gibbs oil to protect our cams.

Here's good write up on differences -

http://www.widman.biz/uploads/Transaxle_oil.pdf

When someone tells you that their GL-5 covers GL-4, remember they are correct as far as EP protection, but that is only half the answer. When they say their Sulfur/Phosphorous additive will not corrode the yellow metals, they are also correct, but if there are enough to meet GL-5 protection, they will slowly peel away your brass synchronizers

Article also says in GL3 and 4 lead was a lubricating additive - just like in gas for valves.  Grear for lubricating but bad for the environment.  In GL5 the lubricant is sulfur and phosphorous.

So you're saying my synchros are peeling as I write this now?

Yes, that's what he saying. No, they are not. I have yet to hear of anyone anywhere who has had a transmission failure from running GL5.

FWIW, synchros are quite nearly free.

Two or three years ago I read that whole 50-page Samba thread and just about panicked trying to figure out what the hell to use when I changed the oil out of B's transaxle. Oil that had probably not been changed since the Reagan administration. 

Bottom line: Stan is right. Go to your nearest FAPS, buy three quarts of 75-90 gear oil and a good long funnel, unscrew the filler plug and pour the stuff in there until it runs out the top. Then wait about 10 minutes and check the level and add a little more if needed until it runs out again. Then screw the plug back on. Then forget all about it until the Sanders administration.

Ummmmm:

Is a transmission supposed to have fluid in it?  

Cause mine doesn't...

Maybe I should have read that super mega best seller by Terry Nuckles; "No fluid in tranny, make it go blammy!!"  "The Asian guide to transmission repair"  (cira 1976) ..

tebs   

Yes, Tebs, but we know that you're a newbie here.  

...when was Brad Penn or Joe Gibbs oil $69 a case (12)?

...those were the days!

My next-to-last case was $66 picked up.  Last year I expected $69, but not the $72 I paid!  Looked at a couple of other sources around here - same thing.

That 3 bucks cut into your Denny's money, El Gordo? You'll meed to skip the Grand Slam Breakfast this Wed.

When I got my Rancho Pro Street transmission I asked them what to use.  They said any good 75-90 lube would work fine.  Shifting is a little stiff when cold but smooths right out, and quiet when warmed up.  That's the extent of my meager knowledge on this subject.  Good luck.

"That 3 bucks cut into your Denny's money, El Gordo? You'll need to skip the Grand Slam Breakfast this Wed."

Whoa.....That'll be hard.

You know, there are exactly two "Denny's" in Massachusetts, and not in the most attractive parts of the state for a bike ride.  I'll have to head down to Rhode Island for my "Grand Slam Breakfast" this weekend (there are four in little Rhody) but then I might detour to "Olga's Cup and Saucer" in Providence, one of my stops on the Rhode Island Bike Trail for that little (OK, really BIG) caffeine boost and a "Carlisle-style", Sausage, Ham and Bacon with Basil and Goat Cheese Pesto Sammich to get us back home.

YUM!