So I am having some issues with the 5 speed tranny on my 89 s13. Sometimes when im driving and i am in gear the tranny will just go into neutral and just rev higher and high until eventually they gear kicks back in and allows me to go but then the next gear does the same thing. any ideas?

 

sounds like worn out synchro's. Probably an extremely abused trans, luckily you can usually pick up a tranny for less than $100.