ax5 trans fluid question (2.5 yj)

Have to drive to Clinton, Connecticut from Cranston Friday to start an internship and want to make sure the yj is running all fresh fluids (I just recently bought it so unsure of most maintenance records). I’ve already changed f&r differential and motor oil. Did a general tune up (wires, cap plugs rotor air filter etc) and greased the front end zirks. Tcase atf3 fluid is newer according to previous owner so what’s left (aside from cooling & clutch sys flush) and probably neglected by previous owner is the tranny fluid.

I’ve done some searching and I am getting a lot of conflicting information from various searches of other Jeep forums so I figured I’d ask you guys.

Searches are coming up with everything from synthetic 10w30, mt90, 75w90 gear oil, Pennzoil syncromesh etc. I read on one forum they praise syncromesh, others say it’s non comparable… Same for gear oil,etc . Synthetic 10w30 seems like the one but I’d like to hear what you guys suggest and use…

Also open to suggestions on getting access to fill the new fluid with the lack of room by the fill plug! Hope to get this done tomorrow afternoon so I hope a 2.5 ax5 owner sees this soon haha.



I’ve read that. Then I’ve read it’s unsafe for the ax5. Don’t have a service manual for it yet and according to opinions I’ve read on forums, the service manual recommends gl5. But then they go on to say this is a typo because gl5 is harmful to the brass syncros.

So as you can tell I’ve done a fair amount of searching but have come up with nothing but conflicting answers haha

I’ve read that a lot of people use Redline MT-90 or Redline MTL in the AX-5/15.

This is on the fact sheet I usually reference from Stu-Offroad:

Is that something I can find locally? Would like to swap it today

Not sure, I have the NV3550 so I run Royal Purple Syncromax.

Thanks fellas. I looked around for some Redline mt90 or mtr but couldn’t find it locally, even checked out the drivers seat in warwick with no luck… Going to have to order it online. For now I put some synthetic 10w30 in there and was thankful I remembered I had a transfer pump because a funnel and hose wasn’t going to cut it! haha