Gear Lube for Synchro Action

SilverGGA · May 20, 2004

I own a Subaru WRX 5-speed. Subaru specs a GL-5 75w90 gear oil. This car's 5-speed is very stiff. Sometimes it hardly gets into 2nd gear before it warms up. Quite a few people uses synthetic gear oil in the transmission (which shares its oil with the front diff), but many complain the shifting gets worse after switching. Some have concluded that more "slippery" synthetic gear oil doesn't provide enough friction for this transmission's synchro gears to work. On the other hand, some has no problem probably due to their shifting speed/style.

I plan to change my transmission's oil when it reaches 15k miles after it fully breaks in. I am considering the following gear oils which will hopefully make it shifts right:
1) Schaeffer's 267 80w90: promises gear climbing action when cold and is a synthetic blend
2) Swepco 201 80w90: Porsche guys love it. Their cars are also hard to shift. Down side is it's non-synthetic
3) Plain old Valvoline conventional 75w90: cheap, available everywhere.

Which one do you think is the best for my purpose?

For the rear end, it is a viscuous type LSD. For absolute long life of the rear differential, is a full-synthetic the ticket? Like a Mobil 1 75w90 GL-5? The rear end is just 1-qt and I can afford to change the oil even every 15k miles.

[ May 21, 2004, 01:13 AM: Message edited by: SilverGGA ]

Bror Jace · May 20, 2004

SilverGGA, do a search on "WRX" and/or "subaru" in this subforum and look at the discussions already posted.

If there's something you'd like to add (another point or question), please resurrect one of those old thread so previous suggestions are taken into account.

--- Bror Jace

Idrinkmotoroil · May 21, 2004

the cold temp stiff shifting seems to be a problem with many transmissions these days, including the one on my car. I personally love the Redline transmission fluids, but given the thickness of the spec'd fluid they likely wont help much at cold temps. I found they work superbly once warmed up to temp, you still have to nurse the transmission a bit when cold. My favourite fluid is the Redline MTL, but I think that is too thin for a GL-5, but they have a fluid for you spec. Any questions you can chat with Dave G. at Redline, he is very helpful and knowledgeable when it comes to transmission fluid recommendations, he helped me a lot.

MolaKule · May 21, 2004

quote:

) Schaeffer's 267 80w90: promises gear climbing action when cold and is a synthetic blend

Stay away from #267 for your vehicle. This lube is for differentials or farm and construction trucks with manual transmissions that use a very heavy gear lube.

DDBCretin · May 19, 2005

Found this old thread when searching for some info about Schaeffers 267.

I recently filled the transmission on my 404 Unimog with 267. I wanted a super climbing oil since I like to drive the truck offroad. Gears 1 and 2 are super low and 267 seems like a good way to lube everything when crawling over rocks and such.

Since I usually need to drive on the interstate to get to a place where I can wheel I also need a good oil for fast driving. (50 mph is fast in a Unimog). I've read a lot of discussion about 404 transmissions getting hot at high speed, so I thought a gear oil like 267 with all it's additives and uber goodness would be good for that too.

It's only been in there for a few hundred km's and everything seems fine, but this thread got me worried.

Should I be? Any advice is greatly appreciated. Thanks.

edmundu · May 19, 2005

SilverGGA, give MTL-R a try. It's made by our very own Molakule, aka Specialty Formulations. I have it in my 2005 Subaru Legacy GT, and I absolutely LOVE IT!

wileyE · May 19, 2005

SilverGGA, IMO suburu differs from other transaxles (and their recomendation) because the engine cranshaft is inline with the car (as opposed to the sideways motors). This means the power has to take a 90degree turn through beveled hypoid gears. I'm of the beleif that this difference requires GL5 type fluid, transmission or Synchromesh fluid may not have the EP adds you need.

On a side note, suburu may spec 80/90 GL5, but every one I've worked on drained out considerably thinner than a 80/90, even thinner than the 75/90 syns I've had. So I'm not sure what the factory fill is? Every GL5 spec fluid I've tried shifts as stiff (until warm, and mainly on the 1-2 shift) as the factory fluid. In some case even stiffer. Miles doesn't seem to loosen them much either, I think suburu just use tight clearance in their build (not a bad thing IMO). I'd love to try a real thin GL5 if anyone knows of one? Then again maybe it's not a viscosity issue, maybe some kind of FM additive would help?

MolaKule · May 19, 2005

DDB,

quote:

Found this old thread when searching for some info about Schaeffers 267.

I recently filled the transmission on my 404 Unimog with 267. I wanted a super climbing oil since I like to drive the truck offroad. Gears 1 and 2 are super low and 267 seems like a good way to lube everything when crawling over rocks and such.

Since I usually need to drive on the interstate to get to a place where I can wheel I also need a good oil for fast driving. (50 mph is fast in a Unimog). I've read a lot of discussion about 404 transmissions getting hot at high speed, so I thought a gear oil like 267 with all it's additives and uber goodness would be good for that too.

It's only been in there for a few hundred km's and everything seems fine, but this thread got me worried. Should I be? Any advice is greatly appreciated. Thanks.

As I recall, #267 is a semi-synthetic of about 18-23 cSt vicosity and is primarily for differentials, since it contains powdered moly.

I would think it would be way too thick for a manual transmission (especially in cold weather) and would not contain the proper friction modification for MT synchronizers.

SilverGGA · May 20, 2005

Wow someone resurrected my thread from last year =D Well of course I've learnt a lot over this year, and chose a GL-5 as required, which was the Swepco 201 80w-90. While it is pretty good after warmed up, it is a bit stiff for my taste before warming up, and I live in San Jose, CA...

So MTL-R will be going in when I change it in a few weeks

DDBCretin · May 21, 2005

Thanks for the reply Molakule. I appreciate the advice.

quote:

I would think it would be way too thick for a manual transmission

The Unimog operator manual calls for SAE 80. #267 is a 80W90 so I think I'm good there. I must admit that this stuff looks really odd coming out of the drum. It does not flow like regular gear oil. You can pour it, but's quite viscous. Kind of like a thin pudding. :-D

quote:

would not contain the proper friction modification for MT synchronizers.

Hmmm. Everything seems fine right now, but it's not been in there long. Assuming its lacking some required property, what kind of symptoms should I be on the lookout for?

MolaKule · May 22, 2005

quote:

I would think it would be way too thick for a manual transmission (especially in cold weather) and would not contain the proper friction modification for MT synchronizers.

Difficult downshifts would be my first indication.

Hey, if it's working now leave it in for the summer and then see how it does during cold weather.

My only concern is the moly disulfide and olefin sulfide makeup of the oil. Moly disulfide is not the best friction modifier for synchros and olefin sulfide may not be the best component for copper alloys. I would do a used oil analysis between 5 and 10k miles to see how its doing.

DDBCretin · May 23, 2005

Thanks Molakule. I'll keep a close eye (or ear) on it.

Gear Lube for Synchro Action

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