Hello all, my 1990 Rx-7 is currently a nice driveway decoration due to my transmission going nuts. After parking the car in reverse, I pulled it back out of gear to row the shifter a bit (I had just installed a new Mazdatrix shifter) and that's when it happened. The car jumped forward like it was in gear, but it was in neutral. I tried to row the shifter again but I could only get it into 1st, 2nd, and neutral. In 1st and 2nd, the car dies when letting off the clutch as if the handbrake were pulled up. In neutral it reverses.
Research on this forum led me to try the NA Miata "Field Repair" in which you jack up the car, pop out the reverse light switch, and jam a flathead or allen wrench in the switch hole to hopefully push the shift rod back into place. I could barely find any info or success stories about this fix on our FC's, so I was wondering if any here has been in this situation as well or has had any luck with this trick.
If there is any other way to fix this I would love to know. Otherwise I am looking at replacing/rebuilding the transmission which just isnt possible for me right now. Please help me!

 

I had a spare FD RX-7 transmission stuck in "reverse".

Had to pop off extension housing and pop all the shift forks into neutral. My memory is a forward gear and reverse were somehow engaged locking the whole transmission up.

I didnt know about the reverse switch hole trick. Try that forsure before yanking the transmission extension housing off.

 

I've seen this happen more often with NA transmissions than turbo ones, but also had it happen on a turbo transmission that was shipped to me and was jostled during shipping. One of the shift forks has slipped out of place. Jack up the rear so the wheels can't put stress into the gear train. The way I pop the fork back into neutral is to take out the detent spring and bb holding the shift rod in position with a magnet. You can then put a small punch or something into the detent hole and push the rod back or forward (Not easy if it's in the car, piece of cake outside). For the punch, use brass or something that won't deform the shift rod or hole. Once it's back where it belongs, reinstall detent.

It's just something that happens, especially as buildup accrues in the places with low oil circulation. Aside from the jostling, the times I've seen it show up have been where the detents are covered in buildup and don't re-engage as quickly as they should. Cleaning and changing oil helps.

 

Thank you for the detailed reply. Going to try this if I can't get the reverse switch method to work. I was doing that method with one of the rear wheels touching the ground which may have made it harder.