Question about AX15 fluid...RichP you out there

[Mdub]

Years ago RichP posted this about AX15 fluid:

"NOPE, not by a long shot, the AX uses sintered bearings [bronze] use of a GL4, 5 or 6 rated lube will chew them up and spit them out. The dealer sells a specific lube for the AX15, stuff is damn expensive too, $15 a quart. It is a GL3 ONLY lube and is labled SPEFICIALLY for the AX15, it's not a hybrid gl2,3,4,5,6 'cover all the bases' lube like coastal or valvoline. GL3 specs include NO sulphur content at all, gl2, 4, 5 and 6 allow sulphur [ever wonder why gear lube smells, thats sulphur]. As I said before I've been running mobil 1 gear oil in mine and have had no problems but I'm down to the last 2 bottles I bought in 99, I buy stuff by the case when possible and will pick up a newer one to see if the specs changed and it now contains sulphur. If it does then the change after next will be with lube from the dealer. I hate to give up the mobil 1 though, it makes shifting in cold weather with a cold drivetrain so much easier. I also run Mobil-1 ATF in all three of our jeeps with the 231 transfer cases. They all shift into 4lo like greased lightning, no grinding or bouncing of the lever.
The only place I don't run mobil-1 is on my 98's 8.25 rear with it's auburn, auburn specifically says NO to synthetic gear lubes with their LSD..."

So seriously, my owner's manual and my FSM says "GL-5". So I went and bought the Mobil-1 synthetic 75w-90 GL-5. Now it is shifting weird into 3rd. So the manuals are wrong. I'm kind of pissed right now.

 

[90xj06]

i beleve you can put atf in the ax-15 transmission and have it run great.

 

[5-90]

1) Yes, the use of GL-3 is correct, and the FSM is mis-printed with the GL-5 datum (GL-5 was standard when it was printed, because most transmissions don't use sintered bronze synchronisers anymore. Pity...)

2) While you can probably get away with using a lighter oil in the manual gearbox, ATF doesn't have the "cling" factor that formulated gear oils have - so it won't lubricate as well. The thinner oil will cut down on parasitic drag, but gear oils are formulated for "dip and splash" lubrication, and will therefore stick to part surfaces much better - forming a protective layer over the part. ATF does not - so you'd see mildly accelerated wear in normal use (I'd think) and you'd have more "dry starts" until you get the fluid going (again, I'd think.) Engine oil would be better than ATF - since, apart from the bearings, most engine parts and splash lubricated - and engine oil has more "stiction" than ATF.

 

[otto]

I use RedLine's synthetic MTL or MT-90 in the AX-15. At $8.00/qt it's pricey, but worth it. Good advice here: NEVER run GL-5 rated oil in the AX-15.

"Stiction"? Is that a technical term? :laugh:

 

[Jeepsloth]

I ran synthetic 10W30 for a while then switched to MT-90 with no problems. When I drained the transmission I ran the oil through a coffee filter as it drained out and saw no evidence of bronze. Shifts better too

 

[ColoCherokees]

x3 on the MT-90. Shifts smoother, runs quieter in my '96 AX-15.

 

[Kejtar]

1) Yes, the use of GL-3 is correct, and the FSM is mis-printed with the GL-5 datum (GL-5 was standard when it was printed, because most transmissions don't use sintered bronze synchronisers anymore. Pity...)

x2 I've been using an AX15 tranny fluid from the dealer (GL3 raiting) and I got at this point probably over 200K miles on it without any issues. All gears shift nice. You can risk other fluids if you want..... but it's one of those "at your own risk" things

 

[ComancheColt]

there was a discussion on ComancheClub about the use of 10w30 in the AX15's of the older trucks. PeteM, the admin on the site, ran it in his and said it works wonderfully.

 

[5-90]

"Stiction"? Is that a technical term? :laugh:

Of course it is! It's related to 'friction' - at least vaguely - and it's a measure of how well something sticks to something else without assistance...:laugh:

 

[w_howey]

anyone have the Chrysler part number for the oil off-hand? Or at least the spec number.... My local dealer is one of those that got Jeep by merger, and treats any parts customers like bastard children. You ask for Jeep parts and they *might* if your lucky look it up.

 

[lawsoncl]

Of course it is! It's related to 'friction' - at least vaguely - and it's a measure of how well something sticks to something else without assistance...:laugh:

Actually it really is a technical term. It's the initial friction between surfaces before they start sliding. Sometimes called break-away friction. Bugger to work into motion equations. http://en.wikipedia.org/wiki/Stiction

 

[RichP]

Years ago RichP posted this about AX15 fluid:

"NOPE, not by a long shot, the AX uses sintered bearings [bronze] use of a GL4, 5 or 6 rated lube will chew them up and spit them out. The dealer sells a specific lube for the AX15, stuff is damn expensive too, $15 a quart. It is a GL3 ONLY lube and is labled SPEFICIALLY for the AX15, it's not a hybrid gl2,3,4,5,6 'cover all the bases' lube like coastal or valvoline. GL3 specs include NO sulphur content at all, gl2, 4, 5 and 6 allow sulphur [ever wonder why gear lube smells, thats sulphur]. As I said before I've been running mobil 1 gear oil in mine and have had no problems but I'm down to the last 2 bottles I bought in 99, I buy stuff by the case when possible and will pick up a newer one to see if the specs changed and it now contains sulphur. If it does then the change after next will be with lube from the dealer. I hate to give up the mobil 1 though, it makes shifting in cold weather with a cold drivetrain so much easier. I also run Mobil-1 ATF in all three of our jeeps with the 231 transfer cases. They all shift into 4lo like greased lightning, no grinding or bouncing of the lever.
The only place I don't run mobil-1 is on my 98's 8.25 rear with it's auburn, auburn specifically says NO to synthetic gear lubes with their LSD..."

So seriously, my owner's manual and my FSM says "GL-5". So I went and bought the Mobil-1 synthetic 75w-90 GL-5. Now it is shifting weird into 3rd. So the manuals are wrong. I'm kind of pissed right now.

Go to your local speed shop or racing supply store, most will have the redline MT stuff in stock. It's synthetic and will work much better in the cold weather than the dealer supplied OEM lube. Also that GL5 was a mistake, they came out with an update about a year later after they had to replace a bunch of AX's under warranty

 

[dyna]

Isnt it the syncros that suffered from the GL5`s sulphur? I put Redline in my AX15, as everybody swore by it for better cold shifting. It worked unreal the first time I shifted into 1st and then 2nd when cold, then it was the same as what ever came out originally at 48K miles. Still pretty sticky onto 2nd when cold.

 

[5-90]

Isnt it the syncros that suffered from the GL5`s sulphur? I put Redline in my AX15, as everybody swore by it for better cold shifting. It worked unreal the first time I shifted into 1st and then 2nd when cold, then it was the same as what ever came out originally at 48K miles. Still pretty sticky onto 2nd when cold.

Correct. GL-series specifications are not reverse compatible (like Sx/Cx specs on engine oil...) and the GL-5 oil has added sulphur as an EP lubricant. Problem is, sulphur is antagonistic to copper alloys at elevated temperatures and pressures - which is why it attacks bronze. Since synchroniser rings are sintered (pressed/formed from powdered metal,) you'll end up with the metal being "spongy" until it loses strength entirely. If you run GL-5 in a gearbox long enough (or for enough change cycles,) you'll start seeing metal flecks in the oil as you drain it - this would be what used to be your synchroniser rings. Oops...

 

[Matthew Currie]

Correct. GL-series specifications are not reverse compatible (like Sx/Cx specs on engine oil...) and the GL-5 oil has added sulphur as an EP lubricant. Problem is, sulphur is antagonistic to copper alloys at elevated temperatures and pressures - which is why it attacks bronze. Since synchroniser rings are sintered (pressed/formed from powdered metal,) you'll end up with the metal being "spongy" until it loses strength entirely. If you run GL-5 in a gearbox long enough (or for enough change cycles,) you'll start seeing metal flecks in the oil as you drain it - this would be what used to be your synchroniser rings. Oops...

First time I drained the box on my 95 I though I'd struck gold.

 

[Jeepsloth]

anyone have the Chrysler part number for the oil off-hand? Or at least the spec number.... My local dealer is one of those that got Jeep by merger, and treats any parts customers like bastard children. You ask for Jeep parts and they *might* if your lucky look it up.

Mopar's "Manual Transmission Lubricant" #04897622AA (MS-9684) sold in 32 fl.oz. bottles.