ax15 synchronizer

[adam greene]

3rd gear is grinding a lil bit bit on up shift, down shift is fine and if you ease it into 3rd on up shift it don't grind. My question is do you think some good amsoil would help it shift a lil better or would it just need a rebuild and about how much would that cost

 

[Mac5005]

Usually the synchros get a burr on them or the keys jump out of the slots and put the synchros in a bind where they cannot match Rpms effectively. One major thing that contributes to this is using conventional gear oil (gl5) in the trans. The sulfur is terrible on the brass. It's much better to use a low sulfur (gl4) oil in the trans to keep the brass from degrading prematurely. If it's grinding now, don't use the high $$ oil until after it's rebuilt. Them make sure to use the low sulfur oil on the new brass.

 

[adam greene]

Okay thanks I didn't figure trying good oil would help much now, anyone have a good shop that could do a rebuild on it resonable price

 

[Chris_M]

If you have access to a press, they are fairly straight-forward to rebuild yourself. Last one I did cost about $500 for parts, but I did have to replace the input shaft, 4 th gear, the reverse gear and idler, and shifter seats/bushings in addition to the bearings and syncros that come in a standard rebuild kit. I think you might be able to source the basic rebuild kit wholesale for about $250-350

But if it is just a little difficult in one gear, drain and refill with new oil of the proper type, and see what happens. I had one that was a bear to shift cold, put in some redline oil and got another 60k miles before if needed to be opened up.