I looked on Shopkey and it said GL-5 (synchromesh) or 75w90. It doesn't say how much though. It says unavailable. I looked up the older ones which should be the same and it says 3.5 pints

 

DO not use GL-5 stuff! That is a misprint in the manual!

Use GL-3 or 4, or 10w-30 synthetic, or MT-90

 

aye the service manual says 3.27 qts of 75W-90, API Grade GL-5 gear lubricant, or equivalent for 4wd models

hth

 

If I'm not mistaken they now recommend 10w-30 synthetic motor oil. I researched this before I changed mine and all the vets say this. So I did and have never had a problem.

 

That sounds about right! I have a 3 cylinder Metro for gas mileage and it calls for GL-5 which is Pennzoil Synchromesh but other trans shops also recommend synthetic 10w30 instead and has about the same feel to it.

 

Crap I already changed it with 75W90 lol. Oh well I'll do synthetic 10w30 next time

Thanks guys!

 

You'll be fine. That is originally what's called for. Just curious, what was in your trans when you drained it?

 

Okay sounds good thanks. In my tranny, the fluid first came out grey. Then turned brown and had white stuff in it. Then the white stuff stopped and the rest of it was just brown with what looked like dirt and crap in it. New tranny fluid made a world of difference.

 

Not sure what year TJ you're referring to, however, i did a lot of research on my 97 TJs AX15, and determined several things. First, the OEM service manual was a misprint mentioning GL5 fluid. It was corrected, but the misinformation persists. Apparently, ONLY a GL3 equivalent fluid should be used. Mobil 1 75W-90 is GL5.
From what i've read, GL5 is corrosive to the gears in the AX15, hence a big no-no. If you've filled it with GL5, id get it out pronto.
I just filled mine, used Penzoil Syncromesh and some Lucas Oil Stabilizer. Noticeable difference, after a few days of driving.
Do a Google search under AX15 and Fluid and you'll find the discussions.

 

Redline MT-90...or MTL. One is thinner and one is thicker. Fill up till it starts to ooze out of the fill hole. Pretty simple.

 

Not sure if oil has ever been changed in my ax 15 trans. Should I use the 75w90 or go with 10w30? Don't want to change out oils and screw something up. Had a 5 ton truck in Afghanistan that I changed tranny oil in, it never ran after changing the oil until we swapped out trans.

 

Use full synthetic 75W90. I finally changed to that and my Ax15 never shifted better. It has never been that smooth.

 

Its GL5 Gear oil for AX15.

Personally I only use Royal Purple Fluids, they are 100% synthetic and have been proven to greatly reduce friction and heat, as well as improve gas mileage.

 

Thanks going to try 75w90.

 

I wonder if you could use 10-30 regular oil insted of synthetic?

 

Put some 75-90 in it and drive!

 

ax 15 lube

Been on this for days, looks like Redline MT 90 is our best bet for the AX-15 The GL5's have additives that eat up the syncro's. They need a gl3 or 4, & thats is really hard to find. the 10w 30 thing just doesn't add up. Redline MT 90 is your safest bet. The Haynes manual was wrong.

 

Been on this for days, looks like Redline MT 90 is our best bet for the AX-15 The GL5's have additives that eat up the syncro's. They need a gl3 or 4, & thats is really hard to find. the 10w 30 thing just doesn't add up. Redline MT 90 is your safest bet. The Haynes manual was wrong.

If you managed to dig this old post up, how did you miss all the others that adequately cover this issue? And who is the "our" in the best bet?

Had I not found 30W drive train fluid, I would have settled on motor oil years ago, both in my AX-15 and my Ford F250.

Not at all certain what you're trying to prove here.

 

Welcome to WF....

You're 6 years late on the question tho....

Also fwiw 10-30 motor oil is the recommended lube by the manufacturer and has been proven over and over to work excellent.

 

Just for the sake of it. I used Redline MTL cause I had a bunch of it left over from when I did my Porsche. It’s just a smidgin lighter than MT 90 at 75w80.

 

Maybe he is a Redline sales rep

 

I would have to go with Asian on this one and run 10w30 since it's worked in Toyotas for years with no problems. The problems only started when Chrysler spec'd the wrong fluid lol.

 

Welcome to the Forum Jokkie666,

Redline is more expensive than regular 10W-30 motor oil. I don't know if one is any better than the other. Both are popular.
Although I don't necessarily recommend it, I'm running STP in my 180K mile BA10 along with 10W-30 regular motor oil. I'm hoping to extend the life a bit until I get a '94 or newer bell housing for the AX15 I have on the garage floor.

As stated above, GL5 gear lube has an additive that wears our brass syncros. Any gear lube you use should state "Yellow Metal Safe" on the container. Motor oil won't have that statement but is fine to use.

Good Luck, L.M.

 

I see the shop the PO used to use put ATF +4 in my manual transmission. This was about two years ago, and I am finding slight issues with 1-2 and 2-3 shift. What kind of damage may that oil have caused? I’ll be swapping the oil out for 10w-30 very soon!!!

Neither he or I have put a ton of miles on it, thankfully.


Sent from my iPad using Tapatalk

 

The T4-5 transmissions used ATF for fluid so i doubt it did much damage i would drain it and flush it though.

 

No way to estimate what or if damage was done... trouble shifting could indicate synchro wear, excessive drag from other wear, or simply the wrong friction qualities.... the ax15 is a pretty robust trans.... just buy a couple gallons of whatever 10-30 is on sale cheap... change it, drive it a week, and change it again..... don't worry about possible damage unless you continue to have problems....

 

ATF goes in the Transfer case.
If a shop put ATF in a transmission that (wrongly) requires 90W GL-5 gear lube, I'd ask the technician why he did so. Some people do things because they heard about them on the internet.

ATF is a hydraulic fluid, but apparently has some lubrication properties because it's used in our transfer cases. I don't know what damage it would do, but perhaps an oil engineer can chime in

The correct lube for our AX-15s is either 10W-30 motor oil (synthetic or non-synthetic) or "Yellow Metals Safe" 75-90 gear lube.
Check the label on the RedLine, Royal Purple or Amsoil container for the yellow metals safe statement.

For more information than you'll care to read, Google: "GL-5 vs motor oil".

Good Luck, L.M.

 

Well this thread certainly clears up this subject. About as clear as MUD!

 

I wonder what happened to Jokie666, revived a dead threaf, stirred some sh!+ and disappeared. Maybe his handle has a deeper meaning.

 

Al poses an interesting question.

HEY Jokie666, what did you put in your transmission?

Good Luck, L.M.

 

ax15 tranny fluid

:beerme:Hey sorry to stir the pot and leave. Computers are not my thing.

I was having some issues with 1st and Rev, in one of my 94 YJs with the ax15, and a clutch prob. with the other, 94 yj. did alot of digging on the computer and came to the conclusion i should dump out my lucas 75w90 because it is a gl5 (even though it didnt say on the bottle) I heard about using 10w 30 motor oil, but went with the MT90. So far the 1st and rev prob seems to be better, but not gone.( Letting the jeep warm up 10 min on cold mornings at the same time too)
wish i knew where i found the thread, but somebody did a thorough looking into on this and came back with 10w 30, or mt90. I went with the MT90. 10w 30 motor oil just seemed wrong. IDK?

I didnt know about the 'yellow metal safe' thing to look for, but its Not on my old lucas 75w 90 bottle. (by the way i had been using that for at least 5 yrs.) Im sticking with the MT90 until I know otherwise.

Again, Good luck!