I recently to a trip back home to Kingston Pa and on my trip my car started to act up. I would be getting on the highway and get into third gear and when I hit the gas too hard it or reach too hi of a speed it would pop out of gear. This happens only in 3rd 4th and 5th gears. It happens only when I seem to be going too fast for that gear or accelerate too fast. When I have my handon the stick it will start to shake and try to push itself out and if I push back I will notice it does not seem to be in all of the way, but if I maintain a pretty constant speed it will be fine and stay in gears.

Does anyone have any idea what could be wrong?

So many problems with this post...tsk,tsk :nono

First off, wrong section. There is a sub-section under 'Performance/Engine' called 'Manual Trans NVT-350' thats where this should have gone.
Secondly, you shouldn't have even posted this there because it's been posted several times before;

http://forums.2gnt.com/dcboard.php?az=show_mesg&forum=34&topic_id=2833&mesg_id=2833&listing_type=search

http://forums.2gnt.com/dcboard.php?az=show_mesg&forum=34&topic_id=1511&mesg_id=1511&listing_type=search

http://forums.2gnt.com/dcboard.php?az=show_mesg&forum=34&topic_id=1011&mesg_id=1011&listing_type=search

and those should provide you with all the information you need.
I know you haven't been here that long but Im sure you've seen one or two flames on this forumn in the month you've been here. You really ought to use the search button as you won't have to wait for an answer, you won't waste bandwidth on questions already covered, and more importantly, you won't piss people off and invoke the wrath of the flame post which will continue for days and has run off many a new member. Good luck, check out those threads, lates.

Damn keith. Calm down.

Originally posted by DarkOne
Damn keith. Calm down.

LOL.

But shit, ya come here with a problem and you can't type it into the SEARCH???

I thought I handled it rather well :twitch
If I came down too hard on you then I apologize, I hope my message came across though. Anyways, fill that bitch with fluid and hope for the best, if not then you're replacing synchros and gears buddy.

Na man its all cool. Everyone I read before was about slipping out of gears and when I was asking around I was told it was a different problem so I thought I would see if anyone could help me.

First and foremost, change the fluid and refill it with dealer-supplied NV-t350 fluid.

Second, do not hold it in gear. Doing so ruins the teflon bushings on the shift forks, which are not sold individually. ruin those, and you replace a whole fork.

If it keeps happening, you have an internal mechanical issue.

yep, it will get so bad, you have to hold it in. i did. and yes, those bushings were ruined. replacing a fork is easy once the tranny is cracked open, however, that was one of the worst experiences i've ever had with my car.... blahhhhh!

unless your a good mech, change the oil, see if it helps, if not, go get your tranny replaced/rebuilt... i'd take it to dino.