I have a 95 integra gs, and on my way home from a family gathering I was on the highway with my father in-law and it kept jumping out of 5th there was a bit of a grind noise almost as if it jumped out an tried to slide back in. This happened bout 5 times before I could get off the highway and drive the rest the way in fourth, any suggestions on why this is happening?

 

the transmission oil may need changing
when was the last time you changed the fluid?

 

could it be synchro rings

 

As mentioned, change the tranny oil, also check the linkage, pay close attention to the extention change rod, #14...
http://www.acuraautomotiveparts.org/...ystemcomp=List All&vinnoT=&trim=&trans=&view=normal

You did say 95 GS right, did you mean 95 GS-R???94