10W30 in the AX15 and AX5

[JWFokker]

Cross-posting from JeepForum, but I found this interesting:

You can put a hose over the tip of the bottle your gear oil comes in and squeeze it up. Its not too bad.

By the way, DO NOT put the same type of gear oil in the transmission that you put in the differentials. Diffs need hypoid gear oil (API GL5) at least, and limited slip additive if you have a limited slip differential. GL5 and limited slip oils used in a transmission will be "too slippery" (not really, but you an think of it that way- it has to do with the static vs. dynamic coefficient of friction of the fluid) for the synchronizers in the manual trans.

What you need for a manual trans is a fluid with excellent gear lube qualities, but without the friction modifiers for hypoid gears, such as a GL3 or GL4 fluid. They make specialty fluids for manual trannies (Redline MTL or MT-90, for example... Royal Purple also makes them) and these are an excellent choice. Shifting gets *much* better with these fluids, especially if someone has ever allowed GL5 oil to get into the tranny. GL5 won't actually harm the synchros, but can lead to grinding gears since the syncrhos will take longer to do their job as you move the shifter lever.

Kinda makes me glad I got impatient and ordered a batch of Redline MTL instead of the Amsoil.

 

[shotgun1976]

Called up the local Amsoil dealer asking if they carried the (MTG) GL-4 which they do, but they said I need to use the GL-5 stuff. Discussed for a few minutes and then they said they would call "Big" Amsoil for me and find out about what they think and call me back. They called back a few mintues later and like I figured they were told to inform me that I MUST use the GL-5 or I wouldn't be covered under the Amsoil waranty (not concerned about that). My concern is that I can't find GL-3 so I will settle for GL-4, but now I'm being told that's not right. What to do? Looking at the Redline site both their MT and MTL are both GL-4. So confused!

 

[RichP]

As far as I'm concerned the GL5/6 spec calls for a certain level of sulfur, thats bad for our AX transmissions. GL3 and 4 have much lower levels of it which makes them better. Now, if you say you have a product that you say meets GL3/4/5/6 you better have tiny little men with catcher mitts in the mouth of that bottle grabbing sulfur particles and that can identify an AX transmission vs a differential when you pour it in or I'm not buying it.

 

[alex22]

AmsOil is most likely telling you to use the GL5 lube because it is what comes up when they search through the factory service manual. It looks like they don't want to get caught up with the lawsuits that could result from customers who use GL4 against Chrystler's recommendation.
As stated before in this thread. If you go to a jeep dealership and ask for some GL5 lube for your AX tranny, when the parts counter guy searches for it a service bulliten will come up with a new part number. My jeep parts counter guy told me that its just repackaged 10w30 oil.
I run the Redline MT90 in mine and the difference is amazing, the stuff that came out was full of bronze and stunk like sulfer.

~Alex

 

[lawsoncl]

As far as I'm concerned the GL5/6 spec calls for a certain level of sulfur, thats bad for our AX transmissions.

That's incorrect. The spec doesn't address sulfur content, but to meet the extreme pressure (EP) requirement of the spec the most common additive is sulfur based. The best indicator of sulfur content or potential damage to brass synchros is the ASTM D-130 copper corrosion test. The article I posted above specifically addresses this and give some good info. It appears that some gear oils such as the AMSOIL GL5 are using alternative additives that are not corrosive to copper (and hence copper alloys like brass).

So AMSOIL may very well be correct is telling you to use their GL5. Personally, I would stick with one of the ones that folks have posted good experiences with such as the Redline or the Synchromesh

 

[RichP]

That's incorrect. The spec doesn't address sulfur content, but to meet the extreme pressure (EP) requirement of the spec the most common additive is sulfur based. The best indicator of sulfur content or potential damage to brass synchros is the ASTM D-130 copper corrosion test. The article I posted above specifically addresses this and give some good info. It appears that some gear oils such as the AMSOIL GL5 are using alternative additives that are not corrosive to copper (and hence copper alloys like brass).

So AMSOIL may very well be correct is telling you to use their GL5. Personally, I would stick with one of the ones that folks have posted good experiences with such as the Redline or the Synchromesh

That brings up an interesting quandary then, if it does not use the EP additives which happen to be S, P and Cl what does it use. All three of them are corrosive to the materials they lubricate, thats how they work.

 

[Matthew Currie]

That brings up an interesting quandary then, if it does not use the EP additives which happen to be S, P and Cl what does it use. All three of them are corrosive to the materials they lubricate, thats how they work.

I idon't know what's in it, but I've been using GL5 Valvoline synthetic in my 95, and it's been fine for approximately 150 thousand miles (now at 262K), so I'm guessing whatever is in it is safe for the synchros.

 

[shotgun1976]

As far as I'm concerned the GL5/6 spec calls for a certain level of sulfur, thats bad for our AX transmissions. GL3 and 4 have much lower levels of it which makes them better. Now, if you say you have a product that you say meets GL3/4/5/6 you better have tiny little men with catcher mitts in the mouth of that bottle grabbing sulfur particles and that can identify an AX transmission vs a differential when you pour it in or I'm not buying it.

Well said. I couldn't help but laugh when I visualized the little catcher.:laugh:

 

[lawsoncl]

That brings up an interesting quandary then, if it does not use the EP additives which happen to be S, P and Cl what does it use. All three of them are corrosive to the materials they lubricate, thats how they work.

I copied this list of common EP additives from another article:

• Chlorinated paraffins;
• Sulphurized fats;
• Esters;
• Zinc dialkyldithiophosphate (ZDDP);
• Molybdenum disulfide (MoS2);

My guess is that the sulphurized fats have a tendency to breakdown at moderate temps (225-250*F in the ASTM test) and release the sulphur which attacks the copper. Fats can breakdown into acidic checmicals as well (think making soap by heating fats and lye). It could be that the other types don't breakdown as easily or when they do, they don't breakdown into something corrosive or acidic.

To me the ASTM copper corrosion test is fairly representative of the situation of brass synchros in a hot tranny, but then again the test is pretty short and doesn't represent a few hundred thousand miles.

 

[lawsoncl]

Here's another article that talks about how EP additives work, active versus inactive sulfur, etc.

http://www.noria.com/learning_center/category_article.asp?articleid=496

 

[joe_peters]

So, Mobil-1 ATF for the TC, and Mobil-1 10W30 for the AX15 would seem to be the best of the deal???

Pain, behind eyeballs, growing, becoming very annoying...

 

[joe_peters]

Crum. Posting to a antique thread!

Must read dates on threads!

 

[PhotographerMike]

Crum. Posting to a antique thread! Must read dates on threads!

Nothing wrong with using old threads. Good info & often good answers to questions that don't need to be asked again.

And since this is an old thread; Has anyone been using 10w30 in their manual trans and put some miles on it without problems. I'm about to dump Mobil 1 in my AX-5 and wanted to check with the experts.

Thanks,
Mike

 

[RichP]

Not me yet, I'm changing it tonight, well my customer is, while I update his shopkey server and workstations with the new quarterly release. Replacing the MT90 in the tranny, mobil-1 atf in the tranfer case and high milage 10W30 in the engine. Oh and replacing the dam struts on the rear hatch, tired of that thing hitting me.

 

[Hellbent]

i forgot to post up here. i changed out my trans fluid('96 ax-15 w/209k) about three weeks ago. went from redline mt90 to mobil 1 10w-30. it so far has made no appreciable difference in noise, shift quality, or anything else really. so far, so good.

 

[joe_peters]

I changed mine, and here is what I posted in another thread:

Ok, here is the official unofficial report:

After 214.9 miles since changing from GL to Mobile-1 10w30 my AX15 shifts better, and I mean noticeably better.

The added bonus is a reduction in noise. As stated earlier, my center console and tunnel boot are not installed at this time. Well, after about 50 miles of the trip I started noticing different noises inside my XJ--small air leaks, empty soda can rolling around, and some junk rattling in the glove box! These are sounds I never heard, or was unable to differentiate them over the trans noise. Totally subjective and "in the ear of the beholder", but I swear it is quieter.

So there you are, the official unofficial and wholly subjective road test.

I would do it again in. Would you get the same/equal results with a 10w30 non-synthetic oil, I don't know.

In closing let me say that this is not a miracle fix--I still have dandruff and athletes foot, so it certainly doesn't fix everything!!

 

[RichP]

I did the upgrades on his stuff tonight and he changed all my fluids, if anything the MT90 shifts a bit smoother but that might be because it was warm in bays. We'll see what happens in the morning when I head out and the jeeps ice cold.
ahhhhh $&#&$&#&^@^#^^$ I forgot to ask him to do the struts....dammit.

 

[nblanton]

I don't know exactly about the differences, but I don't believe that standard 10W30 motor oil is actually good for the yellow metals either. I do a lot of work on manual tranny hondas, and they call for a special honda MTF (manual tranny fluid). The manuals state that 10w30 or 10w40 can be used in a pinch, but should be replaced as soon as possible to prevent premature wear to the synchros. Also, I have a manual transmission repair manual that states that the engine oils have EP additives similar to gear oil. I do know that the 10w30 engine oil is roughly the same viscosity as 70w85 gear oil. I have used the penzoil synchromesh in place of the honda mtf in honda 5-speeds and it does shift much better than 10w30. Also, the mobile1 synthetics actually seem to shift worse than the dino stuff when I've used them. I believe they end up preventing the synchos from working better than regular oil does. I currently have mobile1 75w90 in my AX15, and it shifts f*cking terribly. I was planning on either picking up some redline gl4 or pouring in some synchromesh, since I can get it at autozone or pep boys. I have honda MTF as well, but i keep it for my imports as I have to get it from the dealer. I hope this helps a bit. Also, the oems started using atf as a manual tranny gear lube in the 80's in a lot of cars (BMW's and Fords for sure) because they were lower in viscosity => better gas mileage and don't have the problems with yellow metals that the gl5 hypoid oils have. ATF may or may not work in the AX15. I would be interested in seeing what Toyota recommends for the Supras that have the AX15 in them.

 

[RichP]

I don't know exactly about the differences, but I don't believe that standard 10W30 motor oil is actually good for the yellow metals either. I do a lot of work on manual tranny hondas, and they call for a special honda MTF (manual tranny fluid). The manuals state that 10w30 or 10w40 can be used in a pinch, but should be replaced as soon as possible to prevent premature wear to the synchros. Also, I have a manual transmission repair manual that states that the engine oils have EP additives similar to gear oil. I do know that the 10w30 engine oil is roughly the same viscosity as 70w85 gear oil. I have used the penzoil synchromesh in place of the honda mtf in honda 5-speeds and it does shift much better than 10w30. Also, the mobile1 synthetics actually seem to shift worse than the dino stuff when I've used them. I believe they end up preventing the synchos from working better than regular oil does. I currently have mobile1 75w90 in my AX15, and it shifts f*cking terribly. I was planning on either picking up some redline gl4 or pouring in some synchromesh, since I can get it at autozone or pep boys. I have honda MTF as well, but i keep it for my imports as I have to get it from the dealer. I hope this helps a bit. Also, the oems started using atf as a manual tranny gear lube in the 80's in a lot of cars (BMW's and Fords for sure) because they were lower in viscosity => better gas mileage and don't have the problems with yellow metals that the gl5 hypoid oils have. ATF may or may not work in the AX15. I would be interested in seeing what Toyota recommends for the Supras that have the AX15 in them.

If you are using Mobil-1 gear oil in your tranny it's GL5/6 rated. As for BMW they are also a good source for tranny fluid for the AX's as they have a GL3 lube for their stuff, Eagle used to buy it for his fleet, it was very reasonable price wise. Mobil has not made a GL3 rated gear oil for over 8 years, I used up my last 2 quarts about 3 years ago.

 

[nblanton]

Well, the Mobile1 gear oil got bought reluctantly because the owner's manual in my 1995 states that a GL4/5 oil is to be used. I've never heard of putting GL5 in a transmission, but the manual said to do so, so I gave it a shot. I'm guessing after reading this thread that ChryCo changed this spec. It's (Mobile1 gear oil) definitely not the right stuff for the AX15. So, the BMW dealer has a GL3/4 gear oil available? All of my manual tranny BMW's had ATF in the gear boxes. What models came with gear oil?