89 MJ Posted December 8, 2020 Share Posted December 8, 2020 I looked through the DIY section and didn’t see anything on this first question. 1. The BA10/5 has a stud that holds on the clutch master cylinder. The AX-15 MC does not. How has everyone gone about mounting the AX-15 MC in a BA10/5 truck? 2. What is the correct fluid for an AX-15? I know there was some engine oil that worked, but I don’t remember what or how much. Link to comment Share on other sites More sharing options...
BeatCJ Posted December 8, 2020 Share Posted December 8, 2020 I like the Novak Knowledge Base for the answer to the second question: https://www.novak-adapt.com/knowledge/transmissions/manual/ax15/ "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 This fluid is essentially obsolete; superseded by GL4, then GL5.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." Valvoline makes a Syncromesh fluid that meets the GL-4 spec. I don't think a synthetic is necessary in a manual transmission, I think the gear oil should be changed before regular lube goes bad. Link to comment Share on other sites More sharing options...
89 MJ Posted December 8, 2020 Author Share Posted December 8, 2020 15 minutes ago, BeatCJ said: I like the Novak Knowledge Base for the answer to the second question: https://www.novak-adapt.com/knowledge/transmissions/manual/ax15/ "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 This fluid is essentially obsolete; superseded by GL4, then GL5.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." Valvoline makes a Syncromesh fluid that meets the GL-4 spec. I don't think a synthetic is necessary in a manual transmission, I think the gear oil should be changed before regular lube goes bad. Thank you! Link to comment Share on other sites More sharing options...
87MJTIM Posted December 8, 2020 Share Posted December 8, 2020 I swapped from the BA10 to an AX15 with an external slave cylinder. Which MC did you get? The ones I have purchased came with a stud. Link to comment Share on other sites More sharing options...
Pete M Posted December 8, 2020 Share Posted December 8, 2020 the current mopar recommendation for AX-15 oil is, I believe, Full synthetic 10w40? that or 10w30 Link to comment Share on other sites More sharing options...
89 MJ Posted December 8, 2020 Author Share Posted December 8, 2020 42 minutes ago, 87MJTIM said: I swapped from the BA10 to an AX15 with an external slave cylinder. Which MC did you get? The ones I have purchased came with a stud. Thanks for the reply. I believe mine to be an OEM one with two studs built into it. My firewall on my truck has a stud on it though. Do I cut the stud off of the firewall? Link to comment Share on other sites More sharing options...
89 MJ Posted December 8, 2020 Author Share Posted December 8, 2020 21 minutes ago, Pete M said: the current mopar recommendation for AX-15 oil is, I believe, Full synthetic 10w40? that or 10w30 Thanks! Link to comment Share on other sites More sharing options...
ghetdjc320 Posted December 8, 2020 Share Posted December 8, 2020 I ran regular 10w30 Dino oil and it was quiet and smooth Link to comment Share on other sites More sharing options...
87MJTIM Posted December 8, 2020 Share Posted December 8, 2020 Pennzoil Syncromesh If you cut the one off the fire wall, you will need to drill through the FW. I would take the MC back to where you got. It cannot be OE if it has a stud where the FW has a stud also. You could try pressing out the one on the MC and keep the FW original. Link to comment Share on other sites More sharing options...
jdog Posted December 8, 2020 Share Posted December 8, 2020 what year mc did you ask for? Link to comment Share on other sites More sharing options...
89 MJ Posted December 8, 2020 Author Share Posted December 8, 2020 29 minutes ago, 87MJTIM said: Pennzoil Syncromesh If you cut the one off the fire wall, you will need to drill through the FW. I would take the MC back to where you got. It cannot be OE if it has a stud where the FW has a stud also. You could try pressing out the one on the MC and keep the FW original. 18 minutes ago, jdog said: what year mc did you ask for? This was the MC that came out of my 97 XJ that the trans came out of. The issue is not only the studs, but the holes do not line up on the firewall for the MC. Link to comment Share on other sites More sharing options...
jdog Posted December 8, 2020 Share Posted December 8, 2020 Yeah you need a 94-96 Mc iirc if it's a external slave Link to comment Share on other sites More sharing options...
87MJTIM Posted December 8, 2020 Share Posted December 8, 2020 8 hours ago, jdog said: Yeah you need a 94-96 Mc iirc if it's a external slave You need the earlier style MC. Link to comment Share on other sites More sharing options...
89 MJ Posted December 8, 2020 Author Share Posted December 8, 2020 9 hours ago, jdog said: Yeah you need a 94-96 Mc iirc if it's a external slave 1 hour ago, 87MJTIM said: You need the earlier style MC. Gotcha. Thanks guys! Link to comment Share on other sites More sharing options...
89 MJ Posted December 8, 2020 Author Share Posted December 8, 2020 20 hours ago, Pete M said: the current mopar recommendation for AX-15 oil is, I believe, Full synthetic 10w40? that or 10w30 I found where people said that that is what MOPAR recommends. Is there a more reputable source confirming this? I haven’t been able to find one. Link to comment Share on other sites More sharing options...
gogmorgo Posted December 9, 2020 Share Posted December 9, 2020 I haven’t found an official source regarding the engine oil thing beyond it being reported by people who worked at the dealers. The only TSB I was able to dig up about rough shifting just claims it’s normal for the first few shifts on a cold day to be rough and says to do nothing about it. I put Redline MT90 in my ZJ’s ax15 a couple months back based on recommendations here, changing out the synthetic 10w30 I put in it a couple years ago. Just wanted to try the Redline, but I haven’t noticed a difference in shifting. But in my MJ’s ax5 there was a very noticeable difference running Royal Purple Synchromax compared to engine oil. I’ve also had excellent results with the RP in other brass-synchro transmissions, and I think I’ll be switching to it in the AX15 as well when it comes time to change it again. Link to comment Share on other sites More sharing options...
89 MJ Posted December 9, 2020 Author Share Posted December 9, 2020 27 minutes ago, gogmorgo said: I haven’t found an official source regarding the engine oil thing beyond it being reported by people who worked at the dealers. The only TSB I was able to dig up about rough shifting just claims it’s normal for the first few shifts on a cold day to be rough and says to do nothing about it. I put Redline MT90 in my ZJ’s ax15 a couple months back based on recommendations here, changing out the synthetic 10w30 I put in it a couple years ago. Just wanted to try the Redline, but I haven’t noticed a difference in shifting. But in my MJ’s ax5 there was a very noticeable difference running Royal Purple Synchromax compared to engine oil. I’ve also had excellent results with the RP in other brass-synchro transmissions, and I think I’ll be switching to it in the AX15 as well when it comes time to change it again. Thank you! Link to comment Share on other sites More sharing options...
Pete M Posted December 9, 2020 Share Posted December 9, 2020 ask jdog or eaglescout, I bet they can look up the tsb for ya. Link to comment Share on other sites More sharing options...
89 MJ Posted December 9, 2020 Author Share Posted December 9, 2020 55 minutes ago, Pete M said: ask jdog or eaglescout, I bet they can look up the tsb for ya. Thanks. I think I might have found the route I want to go. I’m leaning towards Redline MT90 Link to comment Share on other sites More sharing options...
gogmorgo Posted December 9, 2020 Share Posted December 9, 2020 1 hour ago, Pete M said: ask jdog or eaglescout, I bet they can look up the tsb for ya. The TSB isn’t in snap-on’s service data, if it exists. I suppose there’s a chance they missed it, but they’re pretty thorough, and it’s not in AllData or a couple other places I checked that I’ve had temporary access to, although I admittedly haven’t talked to a dealer about it. But I find it odd that no one on the internet has been able to find it either. It made me think there wasn’t an actual TSB, just something that someone figured out worked and started recommending. Maybe it was at a dealer, maybe it wasn’t. But it seems like it worked out okay for me. Link to comment Share on other sites More sharing options...
eaglescout526 Posted December 9, 2020 Share Posted December 9, 2020 1992 is how far I can go back to our Jeeps but here is something about the manual trans AX15. I even dove further to confirm what I found is the only instance of the manual trans and its fluid and went all the way up to a 2002 TJ where the AX15 wouldve been used last and found nothing in regards to a fluid change. If there ever was, it is long gone and clearly no longer a concern with Chrysler to take care of those trans with the possibility of GL5 fluids changing to suit transmissions. Link to comment Share on other sites More sharing options...
eaglescout526 Posted December 9, 2020 Share Posted December 9, 2020 I am gonna break it up into sections for better reading Yes, I know I selected 2.5L but I still get the same bulletins regardless. Link to comment Share on other sites More sharing options...
Pete M Posted December 9, 2020 Share Posted December 9, 2020 innnnteresting... nothing at all from about 10-12 years ago? this info sure spread like wildfire for not having any official paperwork behind it. on the other hand, I've not heard any complaints from people running the motor oil so I guess it's ok. Link to comment Share on other sites More sharing options...
Minuit Posted December 9, 2020 Share Posted December 9, 2020 Don't forget that 75W-90 gear oil is equivalent to a 10ishW-40ish motor oil in viscosity. That's not really a fair comparison, but just putting it out there. To add some more hearsay and conjecture onto the pile, my AX-15 shifted considerably better with 10W-30 conventional than with the gear oil of unknown weight I drained out of it. I think the "use 10W-30 motor oil in the AX-15" thing is much more about syncro corrosion than shift effort or anything else - and 10W-30 just happens to be what is normally used in the 4.0L engine, so you could use your engine oil in the transmission. Link to comment Share on other sites More sharing options...
eaglescout526 Posted December 9, 2020 Share Posted December 9, 2020 I looked a little bit further and found this. I remember finding this but kinda forgot about it because all it says is the motor oil helps with shifting properties. Nothing about the synchro's Link to comment Share on other sites More sharing options...
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