Manual Trans gear oil recommendation

Bror Jace · Dec 31, 2005

michaelc80, which Red Line gear oil did you use? 'Regular'? NS? Shockproof? Have you tried to use MT-90 in the same application? It sounds like you used 'regular' Red Line gear oil which isn't friction modified for synchronized transmissions ... and you're saying it's the best you've tried to date?

Trannies are picky things. I'm convinced there is no perfect choice for all trannies. You can ask around and see what others are using in the same or similar applications but when it really comes down to it, there's a lot of "poke and hope" involved.

I had heard years ago some people saying that (in general) Red Line gear oils seem to do better in many applications than comparable oils from Amsoil (some Amsoil fans belatedly admitted this). I thought this was seriously dated ... but maybe not.

scoobdude "Although I don't like to mix oils, in this case it's the only solution as the Pennzoil is GL-4 and the Amsoil is GL-5."

It might be a solution to make the best of the oil you already had in your tranny ... but these days there is a plethora of synchromesh fluids available in everything from ATF weights all the way up to XW-90 weight gear oils.

If you do a search on "MTL-R" or "WRX," you'll see a few Soobie drivers here that have had great luck with Specialty Formulations MTL-R ... my first pick in applications calling for a 75W-90 ... even over anything available from Red Line.

--- Bror Jace

brian fix · Dec 31, 2005

Shucks,after reading Molalules specs on their HDS-5,#75-90 gear oil ,,,,,,looks like really good stuff,Iam starting to get curious on his products,though pricey,,but you get what you get,,,,,,,,,Amsoil by the way is in all of my vheicles in trans,rears ,,BUT check out what Molakule has to offer,,,,looks great,BL

Pablo · Dec 31, 2005

Well I'm not sure I would make the broad brush stroke, Bror, but I think we are talking about a misapplication.

We were talking about the a Porsche and I recommended SVG.

For the Subie I recommend this: MTG

michaelc80 · Jan 1, 2006

quote:

michaelc80, which Red Line gear oil did you use? 'Regular'? NS? Shockproof? Have you tried to use MT-90 in the same application? It sounds like you used 'regular' Red Line gear oil which isn't friction modified for synchronized transmissions ... and you're saying it's the best you've tried to date?

Per Redlines recommendation I used the NS and I'm very happy with the performance.

kendogg441 · Jan 1, 2006

molakule, I sent an email to info@specialtyforumulations, is that you? If not, lmk. My email is [email protected]. Tahnks.

Bror Jace · Jan 1, 2006

Thanks for responding, Pablo. I'm not trying to slam Amsoil ... nor overly promote Red Line's products. Hopefully, someone will try your recommendation and report back here ... if they already haven't.

michaelc80, Red Line 75W-90 NS? That's the stuff without any friction modifiers (for LSDs) ... so that's probably the last one of their gear oils I'd recommend. Go figure.

But on Red Line's site they say about this gear oil and the lack of FMs: "This makes the transmission synchronizers come to equal speeds more quickly, allowing faster shifting and much easier low-temperature shifting."

--- Bror Jace

Pablo · Jan 1, 2006

Bror - I didn't take it as a slam. Your points are excellent - MT's can be quite picky in some ways. It's quite common - an example is Amsoil pulled the S2K 75W-90 which had the GL4/GL5 rating but was a relatively low viscosity gear oil. It worked pretty darn good in some gearboxes, even some specifying ATF. Amsoil comes out with the "replacement" SVG, which is a great differential and heavy duty 75W-90 - but as you mention it's not so great in some trannies that love the lower vis stuff and absolutely is a no go in ATF specifying MT's. On the other hand many MT's specifying ATF love and thrive on just a notch or two higher vis. fluids.

AS for Redline's statements and recommendations, sometime they are a bit confoozled. Now if you take:

quote:

But on Red Line's site they say about this gear oil and the lack of FMs: "This makes the transmission synchronizers come to equal speeds more quickly, allowing faster shifting and much easier low-temperature shifting."

And substitute "EP additives" for "FM's" it makes more sense to me.

michaelc80 · Jan 2, 2006

quote:

michaelc80, Red Line 75W-90 NS? That's the stuff without any friction modifiers (for LSDs) ... so that's probably the last one of their gear oils I'd recommend. Go figure.

But on Red Line's site they say about this gear oil and the lack of FMs: "This makes the transmission synchronizers come to equal speeds more quickly, allowing faster shifting and much easier low-temperature shifting."

Since the transmission really seems to like it and Redline has no problem recommending it I don't see a problem with it. Of course, I've kept the email from Dave recommending it "just in case".

I would like to note that even though Amsoil SG is being called a "miss-application" in this case it is listed in their on-line product guide as recommended for the 2005 Subaru Outback and Impreza 5 speed transmissions.

No disrespect meant to Amsoil because I think they have an exellent product. However in my case it wasn't the best choice.

Pablo · Jan 2, 2006

michaelc80 - sorry I wasn't clear - by misapplication (is that a word?) I meant a couple things, but mainly I meant Amsoil's recommendation, while safe, is mis-applied. It's too high of a viscosity for the application, as you well experienced.

HALSTEADTW · Jan 2, 2006

What about Royal Purple's Max Gear 75w-90, it is GL-4 and GL-5 rated? I've been using this in my 91 3000GT VR4(Rear diff/transfer case/transaxle). Seems to be pretty good stuff!

Pablo · Jan 2, 2006

The other part of what I meant by misapplication is car manufacturers not being more specific than GL4/GL5 when clearly many GL5's are just too viscous for some MT's.

bulwnkl · Jan 3, 2006

mrpcar: I use SF's MTL-R in my Subaru transaxle as well and it's superb stuff. I would strongly suggest you try it or, if not, then Redline's 75W90NS in your transaxle.

Bror: Redline's 75W90NS is the proper fluid (from their line) for synchronized transmissions/transaxles which specify a 75W90 GL5 oil. Their 'regular' 75W90 is too 'slick' and shifting is less than stellar.

Pablo: Could you help me understand the MTG recommendation for Subarus? Subaru calls for a GL5 in their transaxles, whereas MTG is only a GL4 fluid, no? I believe that is why Amsoil corporate recommends SVG (although reports I've seen don't give it high marks for shift quality). I have asked some people on Subaru boards how many miles they have put on their transmissions with the various GL4 lubes/cocktails they're using, and I either get no answer or else a short mileage. Personally, I wouldn't even consider a GL4-only fluid in a Subie transaxle with its hypoid front diff. Can you help me here?

Pablo · Jan 4, 2006

Bulwinkl: You are 100% correct. Subaru recommends GL-5 in viscosities from 80W to 75W-90 for all vehicles except Justy. Justy recommends 75W-90 GL-4. MTG is only GL4 is not GL5. (for clarity sake, GL5 contains more EP additives than GL4). While MTG has a hearty add package, it is not full GL5. The previous Amsoil S2K 75W-90 was dual rated GL4/GL5. The SVG is just too high of EP’s and a bit too viscous for cooler climates in a Subaru. While I think it would be safe to mix the two, and also I think MTG would work fine – it’s not a text book recommendation, so users are on their own as are the folks on the Subie boards with cocktails.

PS sorry for the delayed response – I’ve been monkey busy lately.

bulwnkl · Jan 5, 2006

Thanks, Pablo. I understand the busy. I'm not here that frequently, either these days.

1sttruck · Jan 5, 2006

I use the Dodge fluid in my 5 speed gearbox, which is evidently Castrol Syntorq, a 75Wsomething GL4 synthetic. You can get it online for less than $60 a gallon.

Bror Jace · Jan 5, 2006

"I use the Dodge fluid in my 5 speed gearbox, which is evidently Castrol Syntorq, a 75Wsomething GL4 synthetic. You can get it online for less than $60 a gallon."

Thge OEM Nissan GL4 fluid is reportedly Castrol Syntorq 75W-85.

$60 a gallon? That's $15 per quart!

Thanks, I'll 'settle' for Specialty Formulations at about half that price.

--- Bror Jace

mrpcar · Feb 22, 2006

Ok guys, here is the update.

Per recommendation I ordered some Specialty formulation MTL-R and filled the transmission with that fluid. I ran the car hot and made sure all of the old stuff drained out of there before the new stuff went in.

The results were terrible, cold shifting is now 10 times worst than before. It will absolutely not go in first gear unless the car is completely stopped. Even after warm up. 2nd gear is impossible without double clutching.

The fluids that drained out of the transmission was very light, almost like water consistency.

Here are some questions:

(1). Is there a break in period with the new fluid? I mean do I need for the fluid to run through some time in the gears for it to bond to the metal and maybe then it will work better?

(2). What now? Go back to the factory recommended fluids?

(3). Will overfilling it cause this problem? I mean I didn't measure the exact factory recommended amount to pour in I just put in as much as it will hold until it started to come out o the filler plug.

(4). Should I continue to drive the car, or just park it until i find some other fluids to try?

Anyways, I imagine the synchros are just not working with the MLT-R fluid. The transmission gear enegagement feels very stiff, before it felt a little sloppy now it is tight. I don't have any issues getting into any other gear except 1st and 2nd. But again it just feels very stiff and not as easy as before.

mrpcar · Feb 23, 2006

So far I have only driven 20 miles....

Once warmed up the gear box feels just like before nice and smooth. First gear however is still a little hard to get in unless the car is completely stopped. Even rolling just a little requires a lot of force to get into gear.

I will try again tomorrow morning to see if it gets better. The outside temperature right now is only about 50 degrees in the morning.

I suspect that the oil may be too thick for the synchros to function corretly in my transmission.

Thanks

[ February 23, 2006, 05:05 PM: Message edited by: mrpcar ]

bulwnkl · Feb 23, 2006

It has been said here in the past that it takes a few/several hundred miles at least to let the FM in new/different mtx lube plate and start working properly. How many miles have you run the new fluid so far?

jbl · Feb 23, 2006

My experience with MTL-P 75w85 from SF is that it takes time before the gears are smooth. My gearbox becomes smoother and smoother as longer the fluid has been in the gearbox. I have only put 150 miles on the new fluid and so far it seems like gears are improving by the time given.

My advice is to leave it in and run the car for some hundred miles before thinking to exchange it.

Manual Trans gear oil recommendation

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