10W30 in the AX15 and AX5

[flyingphil]

In any case I'll still stick with MT-90 and Mobil-1 ATF and he agrees with that.

That's awesome, thanks a bunch for the great help dude.

Phil :canada:

 

[sidssm]

The Zf trans in fords use atf. You have to be careful using gear oil in newer trans, it doesnt get to some of the torrington bearings as well as atf especially on cold mornings.

 

[RichP]

The Zf trans in fords use atf. You have to be careful using gear oil in newer trans, it doesnt get to some of the torrington bearings as well as atf especially on cold mornings.

Funny you should mention that, I found out the reason that ATF is used in transfer cases like the 231, 242, etc, it has to do with poor lubrication system and a weak pump, you can put a smaller pump in a tranny or transfer case and use ATF and get satisfactory lubrication. If you wanted to use regular gear lube you would need a much bigger pump and better lubrication design of the 'device'. Just thought it was an interesting view from a guy who does this stuff for living.

 

[97XJ Jeeper]

i have also been running gear oil in my 231 for 3 years and it is working flawlessly.

Anybody else catch that, wouldn't damage the TC.

 

[RichP]

Anybody else catch that, wouldn't damage the TC.

I guess, I've been running Mobil-1 ATF in my 98 since new, 10 years and over 320,000mi and have had no problems and it still shifts like new. Oh and after I drive it for a full tank of gas in the summer I can still put my hand on the TC without burning myself, it's not even hot, that also impressed me. LOL.

 

[Blaine B.]

Suposively 10-30 works well in the transfer case, heard it makes it quieter too.

However if you used gear oil of a heavier weight......I'd think it'd be too thick.

Somebody mentioned using gear oil in their transfer case in this thread, thought I'd throw that out there. What weight were you using?

Sorry to get sidetracked from transmissions. However, the transfer case is not far behind (literally.)

 

[lawsoncl]

10W-30 would be a little more viscous than ATF at 100*C (roughly 10 versus 7 cST), but nearly twice as thick at 40*C (70 versus 35 cST). Probably explains it running a bit quieter. As long as it pumps and flows, it's probably fine. I'm not sure I'd use it in very cold temps, and ATF does have a better detergent additive package. Standard 75W90 gear oil is around 15/100 cST which means it isnt going to pump for crap when its cold. Heck, the stuff hardly pours at 0*F.

I used half Redline MTL and half MTL90 in my AX15 to solve the cold shifting problem. Incidentally the MTL has the same viscosity as a 5W30 motor oil, and the MTL90 a 15W40. That certainly lends some credibility to the guys who claim they run 10W30 in the AX15 with no problems.

 

[Blaine B.]

I never notice my transfer case being loud. Except it does whine a bit when in 4lo at higher than crawl speeds.

 

[american_zero]

I recently had my AX15 rebuilt and got the info from the dealer that the numbers supercede to a 10W-30 motor oil. It is supposed to aid in better cold shifting according to the print out they gave me.

Motor oil and gear oil do use different ratings for viscosity, and a 75-90 gear oil is close to a 10W-40 motor oil.


Hope that helps.

 

[Chaosrider]

So i can understand that 10W-30 should be fine?

This is very important for me as I live in a pretty remote place and can't get these other fluids easily and I don't want to delay too much (I am doing the BA10 - AX15 swap right now, just waiting for the clutch parts to remove the whole thing.

 

[outlander]

I'd like to see some long term results..... redline mt90 is $$$!!!!

 

[Banditt007]

just did the fluids on my jeep a few months ago, dont think they were ever done by the previous owners... is a 98' w/ 130k on it. transfer case i ran the ATF and the 5 speed tranny i ran 10w-30. noticed NO DIFFERENCE at all, when i changed them out.

BTW is the factory sealant red for the diffs? b/c i think when i did those that was the first time they were done as well. i think it ran all factory fluids for 10 years 130k yikes.

 

[Wilbur]

Redline MT-90

 

[JWFokker]

I just got some info from Amsoil on their 75W-90 Severe Gear oil and despite being GL-5, their formulation is yellow metal compatible, so that's another one to add to the list of options.

 

[ktwalker01]

ran 10w 30 for the past 30k miles in my ax 15 runs awesome currently at 172000 miles

 

[jeep ride]

Used to run redline mtl in my old tj ax15 mtl is rated 70w80 is as thin as 10w30 motor oil and it is the same color as dexron III .If you have ax15 or ax5 you should be useing redline gear oil or pennzoil syncromesh

 

[lawsoncl]

Here is an interesting test of several gear oils against the ASTM D-130 Copper Corrosion test.
http://www.synthetic-oil-tech.com/Gear%20Lube%20White%20Paper.pdf -- I certainly wouldn't recommend the Mopar, Royal Purple. or Lucas synthetics for an AX5/15!

(edit - just noticed that AMSOIL paid for the study, so its no surprise that the conclusion favored their oil).

The GL5 oil rating do not require passing the ASTM D-130 corrosion test, but GL4 and the newer MT1 ratings do have to pass the test. A GL5 rated oil can pass the test by using other EP additives besides sulfur. Of course, being GL4 or MT1 rated still does not imply that it has a good viscosity or friction and will work well, but at least it shouldn't attack your brass synchros.

 

[JWFokker]

One one hand, it does seem suspicious that Amsoil paid for the study, but on the other hand, they're not nearly as big as their competitors, so it would be in their interest to get independent studies published if they have a superior product. And while they had the best score overall, I'd balance it against price. And Amsoil is pretty expensive, so I don't know if it would be my first choice even if it is the best overall. I also find the scoring method questionable because not every parameter tested is equally important, though the study treated it that way. I'd like to see someone compile a bang for the buck chart or graph, becuase while the Amsoil lube might perform the best, I don't think it would be the most cost effective.

EDIT: On second thought, that might be more complicated than I first thought. You'd have to account for the cost of a transmission rebuild vs avg. # of miles traveled before repair was needed...and I have no idea how you'd compile all of that information and accurately weight the variables.

 

[lawsoncl]

Well put. I think they skewed the conclusions a bit by weighting the importance of specific test, some of which are irrelevant in a tranny such as the 4-ball test. Overall I'd say the Castrol Syntec did pretty well.

 

[RichP]

One thing about amsoil, if you look at their product line ONLY the synthetics are SAE certified, their other stuff is not. Whether that matters I don't know. I do know that Redline MT90 works and is OK, a tad on the expensive side maybe unless you compare it to Mobil-1 gear oil. There was an issue with Royal Purple, had something to do with their gear oil not being used in their sponsored race cars, I just remember reading it in the back of my mind but did not pay any attention to it as RP is pretty rare up here in the NE, seems to more of a western lube. I did find a speed shop in NJ that carries both the full Redline and Royal Purple product lines but thats the only place I have found and they for sure give no price breaks there. I just order the Redline I need from the local parts store and they have it the next day from Keystone suppliers, RP the waiting time is listed as 5 days.
That said it sure would be handy if I could just use my mobil-1 engine oil, 10W30 'High Mileage' in the XJ and TJ's trannies.