tranny messed up bad

since i got my 87 NA rx7 my transmission has had trouble getting into third gear. Almost every time i shift into third gear it grinds. Today i was decided to see how well i could do a quarter mile and started up. i was doin great in first and second gear, then when i tried to shift into third, it ground really bad then the engine made a really loud whining sound. this sound kept up so i turned the car off. when i started it up it went back to normal. The problem with shifting into third, however, was twice as bad. is this a transmission problem, or could it just be a problem with the clutch. if you have any idea please help..

p.s. also how much would a new tranny cost

I'm gonna say its the clutch, but its kinda wierd that its only one gear...

I'm goin with 3rd gear syncros gone bad. probably gonna need to just buy a new tranny.

Yup! Syncros are toast. If you still need to drive it I supposed you can skip third. :)

http://www.securesite1.com/mivastore/merchant.mv?Screen=CTGY&Store_Code=Test&Category_Code=TRNS

take a look there, you'll find a tranny for a decent price... i have no idea about quality though, i googled that site :-)

Same thing happened to my tranny last month. I got one out of a junkyard for $90.