garran99

I know everyone is saying use MT-90 and alot of people are suggesting RedLine fluid. However on the RedLine website they dont suggest using their MT-90 in a Cherokee AX15. Trying to figure out if this is what everyone is using with no problems or if people are using something else. Thought about going with Royal Purple GL-5 75W-90 gear oil but figured I'd ask first. ProDemand just says GL-5 75W-90 gear oil so wondering if everyone is using RedLine brand for a specific reason. Thank You

Garrett S.

I'm using MT-90 and it works well. The reason nobody wants to use regular gear oil is because modern gear oils have stuff in them that's bad for the synchros in the ax15. As far as I know redline works the best and doesn't hurt the synchros.

00t444e

I put 15w40 diesel motor oil in mine. It shifts smooth and is quiet other than the normal whine in reverse.

PatHenry

I'm also using MT-90 - you don't want a GL5, you want a GL3 or equivalent since as Garrett mentions, there's a risk to the soft metals in the synchros.

I love the MT-90, my AX15 shifts smooth as silk and is quieter than a mouse.

Generally if you go with a high quality gear oil like a Mobil1 synthetic, Redline or Royal Purple, you'll be fine.

The91XJ

Actually, on Redline's site if you select your vehicle they DO recommend MT-90 for the AX15.

Been using MT-90 for a while now with good results. Still have to hit first gear before reverse to skip the grind though