miata tranny rebuild problem

[tnord]

background;

i took my transmission out last week to do a very basic rebuild consisting of only rod ends, forks, and seals. i never took ANYTHING off the input, output, or countershaft. the brass and bearings pretty much all look perfect, so there's really no reason to replace these items in my opinion. everything came apart and went back together plenty easy until i got to the very last step.

i went to put on a new gasket and bolt on the input shaft surround inside the bellhousing when i noticed the main bearing had fallen out of it's home in the bellhousing. i thought it was no biggie and got it back in place so that the snap ring was butted up against the rear of the bellhousing.

problem;
when i went to put the last snap ring on the input shaft that keeps the bearing from falling out again i noticed the groove it sits in was still being covered by the bearing despite my knocking it fully back into place.

symptoms;
through some fiddling i discovered there's actually about a 1/4'' of freeplay where i can pull the input shaft towards where the clutch would be. in talking with some friends it was determined i needed to pull the gearset back out.

i got it out and back on the bench tonight and noticed that when i pull on the input shaft it separates where the synchro on 4th gear meets up with the 3rd/4th clutch hub.

solution?
i'm really not sure where to even start. the only thing i can think of is that i need to press the 4th gear synchro and gear farther down on the input shaft, hopefully it'll somehow lock in place, essentially 'elongating' the protrusion of the input shaft through the bellhousing, and providing access to the snap ring grove.

i REALLY need to get this resolved by early tomorrow afternoon so i can get the gearbox in the car by early evening, and take it out for a minor cage adjustment tomorrow night.

EDIT;
based on the wear pattern on the 4th gear set, i can see that the input shaft must remain in the 'shorter' position. as if i pull it to elongate it, the wear marks don't line up, and the piece inbetween the brass synchro and 4th gear physically contacs the gear on the countershaft. as far as i can tell it HAS to go together the way it currently sits. i'm going to try and reassemble and see what happens.

[lateapex911]

Jeez Travis, I'd love to help, but I'm a big chicken when it comes to transmissions, when mine are worn, I just get another one, LOL.

The only guy who I personally know who has been inside one is John Weisberg. Email me for his phone number. email in sig.

[Eagle7]

Chris Ludwig is pretty familiar with Mazda transmissions.

[JeffYoung]

Aren't the Miata transmissions the same as 1st Gen RX7s? I'd post on one of those forums and see if you can get a quicker answer than you may get here.

[tnord]

got it all together. When i first put it all together i used way too much silicone and took way too long to assemble all the pieces. i suspect that when i went to torque down the bolts that hold the casing together i got false readings from the large amounts of hardened goop in there and didn't get all the pieces together just right, taking away a 1/16 of an inch or so of space that i needed to get the snap ring in.

thanks for trying to help me on a holiday you three.

yes, i believe the gearset on a 1st gen RX7 is extremely close to a miata.

[ddewhurst]

***yes, i believe the gearset on a 1st gen RX7 is extremely close to a miata.***

Said another way, EXTREMELY close. Put another way, different input shaft length & gear ratios.

Travis, lots of great info on this site but keep im mind the specmiata site.

[tnord]

***yes, i believe the gearset on a 1st gen RX7 is extremely close to a miata.***

Said another way, EXTREMELY close. Put another way, different input shaft length & gear ratios.

Travis, lots of great info on this site but keep im mind the specmiata site.
[/b]

i'm not sure what you're saying about the similarities (or differences) in the gearboxes...but i was banned from sm.com for saying stuff daniels didn't like.