Ohk I have a ax-15 tranny having a little problems going into gear. I replaced the clutch master cylinder, clutch, pressure plates, release bearing,pilot bearing, flywheel surviced. Basically everything was replaced except what's in the gearbox itself. Sense I changed the master cylinder it is going into gear a lot better so far. But I'm wondering if this syncromesh fluid by amsoil will help it even more? Or make it worse . Also it's a 1988 jeep Cherokee. Thanks for the help!

 

What do you have in there now? I believe that synchromesh is a GL-3/GL-4 spec oil, which is what you want to use in the AX-15. If you put a GL-5 spec oil in (which is what it probably had from the factory) it can cause some long-term damage to the synchros.

 

It's got 75w90 amsoil in there right now im pretty sure

 

its gl 3 or 4 i know its not 5

 

"Synchromesh"-branded is generally good. Most transmissions that require synchro-specific fluids use the brass hubs. (modern ones being ATF, motor oil, or MT-1)

Amsoil is probably fine. Royal Purple 75w90 achieves GL-5 rating without the use of the corrosive sulphur EP additives. Redline MT-90 is also a fantastic fluid.