I have an 88 formula with a T5 in it and its stuck in 4th gear and wont come out of gear at all. The clutch still catches so I can move the car but I have no idea whats wrong with it. I havent had a chance to drop the tranny yet but I was just wondering if anyone knew what problem would cause this to happen. Ive asked a few people and they just guess but said things from the shift forks, throw out bearing, shift linkage, slave cylinder and the syncronizers. If anyone knows the cause please let me know so I have an idea what im getting into when I do drop the tranny.

 

No telling for sure without opening it, could be the fork. Don't try to force it out of 4th, it could break the fork if it's not already broken.

 

Its done for, start looking for a new one.

Been there, got stuck in 4th one day, had to drive home like that.
Played with it, changed fluids, got it out, seemed fine, took the same route when it got stuck in 4th and this time it got stuck in 5th.

Had to drive home stuck in 5th, if you don't think you can start off in 5th gear, your wrong, its just very very very hard and you need lots of room and a good dozen starts n stalls till its rolling enough to move but it will work

 

This may help you once you get the trans out if you decide to see what happened to it.

http://www.pomoforacing.com/tech/T5Rebuild2002.pdf

 

A friend of mine had the same problem years ago in his 89 RS. The cause turned out to be a bent input shaft. Any of the parts you listed could cause it to stick in 4th though and you won't know for sure till its out of the car and taken apart.

 

You were right the trannys destroyed