Why won't my Toyota Corolla go in third gear?

Answer 1

I've been researching this myself as well. I have a 1996 Geo Prizm that uses the same 5-spd transmission. 3rd gear grinds but will not engage. I replaced the transmission with one from a 1991 Toyota Corolla from the junkyard. Except for the speed sensor, they are identical. I still have the same third gear problem. I consulted a friend who is a 20+ year GM mechanic and did some internet research. I believe that these transmissions (C50 and C52 models) have bad third gear synchronizers. I dissected the old transmission, expecting to find half a gears worth of metal shavings in the case. It looks really clean - I plan to have an expert inspect the third gear parts, since I'm not sure what a worn synchro looks like exactly. It's very frustrating to replace a transmission and have the same problem as when I started! The car is driveable, I simply shift from second to fourth. All the other gears engage and work perfectly. I wish I had a better answer, like an adjustment or something, but it looks like these transmissions have a weak third gear part that goes bad before the rest of the unit. I think the only cure is to have the transmission rebuilt with new synchros.