transmission grinding

[mud r us]

I have a 1990 YJ with a 1997 AX-5 transmission that has roughly 45,000 miles on it. The guy I bought the jeep from said that he haaad replaced the fluid with full synthetic 75w-90. It has an external slave cylinder and the fluid level is good. It started grinding when I shifted from second to third. Now it has gotten worse it also is starting to happen when I shift from first to second and getting it into first has gotten harder. I have been told that you should not run full synthetic in the transmission. Can someone point me in the right direction?

[muddYJeep]

Ya I have a 90 too. I assume my Transmission is a 90 as well. Got mine used. I had grinding and found out it was that the TC was VERY low on fluid and the grain was grinding. Also the front shaft spinning didnt help but I've almost fixed that problem. Don't know if that help or not.

[Darrel]

you know, that sounds like a case of worn out syncros (sp). my lil bros was doin it and that was th eproblem and now mines doin it too... but i got about 93,000 on it...

[jimithing27]

Synchronizers are shot.... Commen in all jeep trannys that use Brass synchros ..... Regular GL-5 gear oil contains sulpher which eats brass.....

[CarlosHR]

how hard is to change the synchronizers i am quite a bit to do mechanical stuff

[steeve555]

Redline MT90

[jimithing27]

how hard is to change the synchronizers i am quite a bit to do mechanical stuff


Ever Rebuild a Tranny??? That's about what you are going to have to do.... It has to be taken completly apart....

[Darrel]

I can't say anything from first hand expereance but from what i've been told arround here it isn't an easy task. i wouldn't try it...