This is post rebuild documentation for a first gen RX7 transmission.
A little history. I've been racing my rx7 for years, and I have used up a few transmissions. Usually these were junkyard boxes with well over 100k miles, and I would get a couple of seasons before the synchro's would wear beyond a usable point. I did actually have 3 transmissions built by 2 different race shops. One of those never finished a race, another lasted about one season before failing catastrophically, and the third actually lasted several years - the longest lasting box I've had. So, 1 out of 3 success rate on pro built boxes.
This time around, no luck finding any junkyard boxes and both shops I had used in the past have closed up now, so it was time to dive in and do a rebuild.
I learned a lot on during this effort, mostly how not to do it like:
Don't watch your buddy disassemble the trans while shooting the E36 M3 with him, taking no notes and maybe 3-4 vague pictures, then put everything into a couple of boxes for 4-5 months. And don't pull everything out and try to get it organized, then box it up again to free up space for other projects. And buy the replacement parts you need a couple months later, then try organizing again and set aside, etc.
Now to be fair, that same buddy who helped me disassemble and diagnose, very kindly sold me one of his spares, so I thought there was no huge rush - I was happy to kick this can down the road. Which brings me to another how not to do it: Don't install a new transmission without testing it in all gears first. Yep, the trans I bought for some reason didn't have neutral, which I discovered after putting it in. Out it came and the old haggard box got put back in for one last race weekend.
When I finally got down to doing the rebuild, I was trying to organize all the parts. I laid them out on some paper on a table with notes and sequence drawn on the paper. But this really didn't do it for me. It was really hard for me to quickly figure out what went where (note I was fortunate to have a few examples, so I have a partially disassembled unit as reference sitting on the table with all the parts).
As a way to manage the parts better and keep them in order, I came up with this from scraps I had lying around - my transmission abacus! Really helped me visualize the assembly and keep things sequenced and facing the right way. There are 4 "gear stacks" in the transmission, so I have four posts on the left and corresponding ones on the right. If I need to get at any parts in one of the stacks for cleaning/inspection or to replace with new, I can just slide parts over to the right side until I get to the one I need at the moment.
I also needed a reaalllly deep well socket for removing a nut off the main shaft. This took a whole lot longer to fab than I expected because my chop saw died before a got nearly all the way through the socket. I had to use a combination of much less suitable tools to gnaw it the rest of the way off:
