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How much thinner Gear Oil can I use in my tranny?

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Well, its -35 F outside right now and I just went and drove my car.... My tranny was froze pretty solid.. I let my car warm up for 15 minutes and when I let the clutch out, the cold tranny killed the engine. :banghead:

 

Can I run thinner oil in my tranny and if so, what kind? I was wondering about SAE 30 if that'd work?

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NO! Regular oil isn't designed for the pressure the gears will subject it too. Try Redline brand of gear oil. It's expensive, but they it's awsome stuff, and maybe they have a low temp version or something. You musn't use regular oil tho, or your tranny will be rather pissed.

 

GD

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I've been using Amsoil synthetic gear lube, I think it's 75W-90. It sure made a difference on some of those cold mornings. It cost a few bucks more, but worth it in my opinion.

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Although I don't want this to become another pissing contest of synth vs. dino in man tran's, as I stand behind dino 100%... allow me to say that the dino oil I use and trust to engage synchros correctly has only been working better as the temperature has dropped here in FL...

 

I can't be sure what happens in 35 below though, maybe synthetic is thick enough at that temp to allow proper synchronization. Here in FL at 90 degrees in the summer, synth it out...

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synchros? I take it you mean the gears ingauging right?

so for cold weather run synthetic, hot temperatures use reg gear oil?

 

Also who knows something about tranny heaters? I was thinking about getting a batteryblanket and wrappign it around the bottom of my tranny for the time being..

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1 more vote for synthetic

 

has worked much better for me. synthetic does well in both hot and cold extrems. redline is great stuff espically try the MTL lube. its only for man. trans. its like a thiner weight. but it protects aganst wear like a thick gear lube. and synchros ( the dogs that help you engage a gear) will love it.:clap:

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someone here on the board once suggested tractor hydraulic fluid, as it is designed to withstand high pressure, and some tractors use the transmission as the hydraulic reservoir.

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hmmm.. good idea, I'll have to put that past my soob mechanic. ( I do the work myself, I just go for him for parts and getting help with short cuts on working on the car..

 

Best advice he gave me was about getting the crankshaft belt pully off.. Put a breaker bar on it, brace it against something solid and turn the key.... Spins the nut right off..

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I've been around a tractor or two, and it's odd. They can pull any damn thing, they got a hella ring and pinion in there, and they run plain jane hydraulic oil. Weird.

 

One other note. Big Rig trannies. Like the big 13 speed deals. They don't run gear oil, either. Some use R+O oils. You might go down to a truckstop and see what they got for transmissions, if memory serves me correct, some might be synthetic, and are pretty low viscosity.

 

I neither recommend nor condone the use of these oils.

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although the tractor fluid can withstand the pressures, but maybe it wont hold up to high speed, flying off gears and such.

 

what about temp differences between transmissions and hractor hydraulics?

 

maybe a blend of tractor fluid to regular gear oil, and in like the mmo treatment for motor oil?

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Tractor hydraulics can get very hot, so I don't think temps will make a difference.

 

I'm a firm believer in trying something to see what happens.

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i dont think blending it down would be any different than mixing in ATF.

 

ATF(in power steering systems) works similarly to hydraulic systems, so if tractor fluis is thicker........

 

i dont think it would hurt to try using it in the same manner as using ATF

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I do work on heavy equipment and not all tractor fluid is the same. there are manny different types for different vehicles. it is an interesting idea and may work.( Im not trying it on my car) tractor oil is about a 10W depending on wich one you use. regular motor oil is thicker than that. and some cars (honda) come with 10/30 in the tranny. so there really are lots of options for experimentation.

I still swear by red line MTL and everyone else that I know that has used it say the same.

do wathca want.

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Definatily Redline rocks, switched my Brat to it about three years ago. I can't compare it to Alaska winters but have seen the difference when it was in the teens. The difference between night and day. Do not use Mobile 1 gear oil as it is too slippery for our transmissions, will cause gears to scrape etc, I know this from personal experience and was deepily saddened to have to dump it out of my transmission after only a couple of weeks. I forget were I ordered it from but seems like it was around $7 a quart but worth every penny. As a side note newer model Mustangs come with 30w motor oil in the manuals, I also know this from personal experience. Also the viscosity of gear oil is rated differantly than motor oil, 75-90w gear oil is similar to 15-40w motor oil viscosity wise. Though I wouldn't try it unless recommended by manufactor, definatily go Redline. Glenn Taylor.

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