So here's what I know: The manual transmission on the 85 300zx turbo and the 82/83 280zx turbo are both the Borg-Warner T5, FS5R90A, (Datsun ZCARS and Borg-Warner T5) but they have different gear ratios. The questions I have are: (1) Are the synchro rings interchangeable? (2) Would a rebuild kit for one work for the other?

I'm looking for a rebuild kit for my '85 turbo, and I want to replace the synchro rings in particular. The transmission isn't to the point of grinding, but it doesn't shift smoothly either; it gets caught for half a second between gears. I've found a few kits here: Manual Transmissions by Unit Code: FS5R90A: Manual Transmission Parts - Online. The problem is, the kit listed for the 84-86 models doesn't come with synchro rings, and the kit that does have synchro rings only lists the 82-83 280zx. I've found a few other kits for the FS5R90A on ebay, but, again, I just don't know if the kits vary between the actual car models. I'd just buy the 84-86 rebuild kit and the synchros separately, but I can't find the synchro rings online anywhere. Any help or insight would be appreciated. I've done some pretty extensive searches online, but I'm also new to this so maybe I'm looking in the wrong places.

 

Second paragraph: ZBUM's Z31 Transmission Information Page

I think the Mustang rebuild kit option is discussed in several threads on the forum.

 

Thanks Ken99. I'll look into it.