i just put a ls swap into my hatch and sometimes if i let out fast on the clutch into 3rd it will pop out of gear and it grinds a little in 3rd also does this mean my synchro is bad. It is only 3rd that does this no other gears have any problems wha so ever

 

Bad synchro and possibly a bent shift linkage. Check everything under the car and make sure the rods aren't binding and that your bushings are nice and stiff. My car used to pop out of gear too, once in a while, but with the addition of some energy suspension bushings in the shifter, everything worked itself out.

 

ok i will try that thx man its really wierd it only does it in 3rd gear and when i let off of the clucth fast

 

ok i have a tranny problem on my civic coupe rite now tha tranny is makin a really lod noise in tha tranny i put a new throw bearin but it seem like it not tha bearin at all so it a bad sign or... maybe i need a new tranny