So I took a gamble and bought a t56 with supposedly a few issues. One: it whines in 1st, 2nd, and 3rd gear. Two: sometimes it doesn't want to downshift from 3-2. Never opened one up before. But this one looks like it has been, the tailshaft is cleaner than the body, also the front shift is tight as can be. Supposedly it only has 90k miles. 88 from the original car and 2k from an LS1 swapped RX7. What do you think my issues are, bad synchros, bad gears...? Thanks guys

 

Bearings, blocker rings, but we're all just guessing. Open it up and read all the rebuilding pages available and put it back together in a known good state.

 

If you plan on opening it up, do a search for t56 rebuild on here. There's a really helpful, where the op took apart and rebuilt a (gto?) t56. Also, there should be a link to the manual for it too. Assuming you're a first timer!

 

I've never opened up a t56 yet I have helped my dad rebuild a couple of manual transmissions. Thanks for the input guys

 

It's really not that hard as long as you have the right tools and are methodical about disassembly and storage/order of the parts. Getting the preload just right is probably the hardest part. It's a fun project. Hopefully you don't need a mainshaft like I did. Make sure to inspect the splines on the 5/6 driven gear. It's a relatively common issue that the gear eats into the mainshaft because the fit of the gear on the shaft was too loose from the factory.