ive got a b18c with a s80 lsd in my ek...everything was working fine until a few days ago...when i put it in reverse it doesnt go all the way in and my backup lights dont work..when its in reverse it wont come back out until i hit it out...i check the linkage, changed trans oil, and checked the backup light switch already and it works but its still doing the same thing...i even tried going into another gear b4 i put it in reverse but its the same...any input would be great thanks

 

your 5th or reverse synchro mesh on the sleeve probably has burrs and is binding on the 5/R hub...not allowing it to get all the way onto the gear. or your 5/R shift mechanism tab for the fork is bent.