Topic: Transmition Lubricant

[dwtaylorpdx]

Ran across this and its kind of interesting. Some opinion some documented details.

http://www.allpar.com/fix/gear-oil.html


Dave

[FourbangerYJ]

A buddy of mine is running  some 5-30 in his AX-15. It's been in there for close to a year. I don't know how many miles he put on it but, so far it has not burned up.

[sharpxmen]

transmission oils have different additives that are meant for extreme pressure between moving/contact parts. On the other hand most modern motorcycles share the oil with the motor in their transmission, however the loads in a motorcycle transmission are far less than the ones in a vehicle mostly b/c of the weight (at least 10x less) as well as the loss in the drivetrain. there is also the fact that in an engine the lubrication is forced by the use of the oil pump compared to the manual transmission where it's splash. I have read some Q&As on Mobil's website and some folks were asking if it's safe to run 10w or 5w (can't remember which one exactly) in the transmission - the answer was that the oils are different and the tranny one is formulated and has specific additives and that they don't recommend the use of motor oils in transmissions. It will lubricate but i would think that the wear would be higher and in the long run you would end up with problems so imo since you only change the transmission lubricant at 50k miles or more (some are lifetime) i would spend the extra $ for the proper one.

[dwtaylorpdx]

My Toyota 4x4 (1985) Came with Synthetic motor oil as the article describes, and did quite nicely for 230K miles on it.

Coincidentally the transmission it came with is the same internals as a AX15.....

I don't recommend willy-nilly changing fluid, but the article provides some actual data about
whats in each oil which is pretty important if you chose to try something new.

Mostly it reminded me that our transmissions DO NOT want GL5 lube in them.... :)

Dave

[jdarg]

I stopped reading when I saw they are still spreading the GL-5 misinformation. The additives in GL-5 were fixed a long time ago.

I've run nothing but M1 75W90 in my AX5 since it was new and it now has 120K on it and shifts perfectly. Surely if GL-5 was a problem it would be acting up by now, at least a little, wouldn't it???

[sharpxmen]

My Toyota 4x4 (1985) Came with Synthetic motor oil as the article describes, and did quite nicely for 230K miles on it.
[...]

don't want to get into a back and forth match, just so you know - i have yet to find an official doc from any vehicle manufacturer using Aisin transmissions stating that (searching online for manufacturer recommended oil types) - how do you know it was motor oil? was it listed in the user's manual as recommended transmission oil? I'm just curious b/c the only thing i ever saw was that the base for the oil is the same but they have additives specific for transmissions. there is a lot of talk about it on forums though in regards to "conspiracy", but i would think (or at least that's what i would do) that would have been more profitable to do that for motor oils (considering the sales volume).

[jfrabat]

To be honest, I would only do this in a pinch (say, for some weird reason, my tranny ran out of oil in the middle of nowhere, and I only had motor oil available) and would change it as soon as possible.  I rather you all try this with YOUR tranny's and then let me know how it goes...  But I am not about to test this theory on mine.  I used to work for Esso (Exxon Mobile for those of you in the US), and they additives are certainly different (we had an oil blending plant as part of our business, and I bought the additives, so I know they were different; how different, I cannot tell you, as I am no chemist, but they WERE different!).

[dwtaylorpdx]

don't want to get into a back and forth match, just so you know - i have yet to find an official doc from any vehicle manufacturer using Aisin transmissions stating that (searching online for manufacturer recommended oil types) - how do you know it was motor oil? was it listed in the user's manual as recommended transmission oil? I'm just curious b/c the only thing i ever saw was that the base for the oil is the same but they have additives specific for transmissions. there is a lot of talk about it on forums though in regards to "conspiracy", but i would think (or at least that's what i would do) that would have been more profitable to do that for motor oils (considering the sales volume).

No prob, I don't really have a dog in the fight, its just a interesting article...

Yes, the Owners manual spece'd Castrol Synthetic 20W50 Motor oil for the transmission.
I just followed directions, the Dealer told me there was also a true gl4 gear lube that
was like a 40W70 gear lube, but it was really hard to get at the time.
They also specified a 12000 mile change interval on the tranny.
Which at the time I thought was crazy because they said the Air filter was good for 40000 miles...


I only posted the link because it had some interesting points in it.

I'm running the real Mopar AX5/AX15 lube in my YJ and I'm very happy with it.
I've also run Redline and Amsoil  and they worked pretty good.

I quit using dyno 75W90 on the second transmition replacement due to
bad syncros and bushings in the tranny. (I'm on transmition #4) First 2
went under warranty. The Jeep dealer put the GL5 70W90 in both times.

Funny thing as well, My 85 Toyota Was Japenese built, the US built
trucks of that year came with 75W90 GL4...

Dave

[sharpxmen]

No prob, I don't really have a dog in the fight, its just a interesting article...

Yes, the Owners manual spece'd Castrol Synthetic 20W50 Motor oil for the transmission.
I just followed directions, the Dealer told me there was also a true gl4 gear lube that
was like a 40W70 gear lube, but it was really hard to get at the time.
They also specified a 12000 mile change interval on the tranny.

interesting, thanks for clarifying that.

[dwtaylorpdx]

I miss that toyota,,, ran good got 25MPG highway and it never broke down... Unlike my US made jeeping wonder....

Dave