This?I went down this rabbit hole a long time ago and read way to much shit lol. I found somewhere in that hole that a straight SAE 30 synthetic is yellow metal safe and has the correct specs that these trans require. So for the last 5 jeeps ive owned, Ive swithed the trans oil to mobil1 sae 30 synthetic and they all shift like butter. Even the 1 i had that didnt shift so great when i first got it shifted like new after i swapped the gear oil out of it.
I used mobil1This?
This is what Novak has to say
Transmission Fluid
The factory manuals call for 75W90 GL-3 gear oil for the AX15 transmission. This fluid is essentially obsolete; superseded by GL4, then GL5. However, many GL5 fluids have friction modifiers that are not compatible with synchronizers, so make sure to check for compatibility.
It is the experience of some that a 50W fluid provides quicker shifts and especially so in colder climates.
If it specs gear oil you'd not want to use engine oil.This?
There was a tsb years ago that said not to use the manufacturer suggested gear oil.If it specs gear oil you'd not want to use engine oil.
Gear oil is what I'm seeing with a quick search. What does the TBS spec?There was a tsb years ago that said not to use the manufacturer suggested gear oil.
An engine doesn't produce pressure on parts that are protected by a thin layer of motor oil?Gear oil is what I'm seeing with a quick search. What does the TBS spec?
Engine oil normally isn't a good substitute as it doesn't have the proper additives for high pressure like gear teeth see.
An engine doesn't produce pressure on parts that are protected by a thin layer of motor oil?
Uh crank shaft? You guys run your "gear oil". I've got a decade of shifting on a 91 yj with 30w synthetic in it.How much torque does it take to rotate a camahaft. What's the contact patch of a pair of timing gears?
I'm not saying you're wrong. Tons of old iron 3/4/5spd transmissions ran 30/40/50w motor oil.Uh crank shaft? You guys run your "gear oil". I've got a decade of shifting on a 91 yj with 30w synthetic in it.
I got all fancy and put this shit in.
No idea how it works yet, but it seems to shift nice without the motor running.
I deal with lube oils on a large scale and it's interesting how some shops pick what they use.Uh crank shaft? You guys run your "gear oil". I've got a decade of shifting on a 91 yj with 30w synthetic in it.
I do know that if your engine oil is JASO certified it has the pressure additives in it for gearbox use. I like using Rotella 5W-40 for this reason, I have a couple of rigs that run that in both engine and transmission, mostly high-miled Jap rigs that regular trans oil changes get the "iron" these things start to create after 100k out on a regular basis is beneficial.I deal with lube oils on a large scale and it's interesting how some shops pick what they use.
It's a challenge figuring out the proper lube for some stuff. Especially when digging in the rabbit hole to find any manufacturer info, why a specific brand/type which hasn't existed in years was spec'd etc.
Engine oil is designed to handle combustion byproducts and there's generally less pressure in parts vs in gearboxes.
I can think of several other oils that would probably work in a transmission.
Get him on here and have him start a post about it!It's certainly overwhelming when looking at options.
We have a greybeard at work that digs into lube specs as a hobby. Dude is like Rain Man in this stuff.
That’s the internet for you.So we have 2 that say synchromesh and everyone else has a different opinion
At least mines not on the floor. It's actually mounted. Maybe in a couple years it will run.That’s the internet for you.
My ax15 is still sitting on the floor waiting to go in so I am just an observer to the discussion