strange transmission problems?? any help?

[preston240sx]

ok so i replaced the transmission in my buddys sr20 it kept popping out of 4th gear so we thought it was a transmission problem and ordered a new one from jdm miami . put the new transmission in today took it for a test drive and guess what.... the new transmission popped out of 4th .... what would could cause this ? im thinking we might of pulled a good transmission ?....... if it happens on the new one ... any input will help thx

[alms24sebring]

thats sounds wierd. idk I would think something is in the way of the shifter at the boot or something??

[preston240sx]

stock shifter .... transmission is sitting just like the other one was ... same as my rb does too..

[alms24sebring]

Wow, I dont really know then unless your the lucky ones with 2 bad 4th gear syncros.

[preston240sx]

im having trouble telling my self its bad syncros again... ...lol