Transmission pops out of 5th gear

Its not fluid levels and it is not syncro's. Its a defective 5th gear. Sorry to say man but it's shot. This is not an easy fix or a cheap one (unless you are doing it yourself). Looking at $400 just in parts. I had this happen to me. I have done a ton of research and found comprehensive information that has educated me on this common problem in these transmissions. What has happened is the teeth on the 5th gear have worn down to a point that it will no longer allow it to catch and stay in gear. Anytime it is put under any kind of load it will just pop out. Why does this happen to countless Nissan NX and Sentra owners? Faulty engine and transmission mounts. So it is also recommended to replace all 4 mounts in your car when doing this fix. Here is a Web address that will take you to a forum that will describe the problem, what parts need to be replaced, where you can buy them and how to replace them if you chose to do that. You will save yourself about $600 in labor. If you don't choose to not do it yourself you will at least be able to give the mechanic a detailed description of what is going on and how to fix it. Here is the web address. Good luck. http://www.sr20-forum.com/general-maintenance/18390-how-recognise-repair-5th-gear-pop-out-b13-b14-transmission.html

More than likely the shifter parts or worn out, rebuild it.

If just occasionally overheats and only in 100 degree weather, possible sticking thermostat, debris buildup on the exterior core of the radiator, corrosion buildup on the interior of the radiator core, low coolant level or insufficient fan cooling capabilities.
if you shifter is pulling out of gear when you hit the throttle that is call pop-out. This usually happens in 5th gear so it is called fifth gear pop out. Anyway, this is an internal transmission problem that can be fixed but will require pulling the tranny and opening it up.
please vote if this helps

On these WC Volkswagens, you have to make sure that the little ball-and-socket gear linkages are connected. If one is off, replace it with new, because the old one will probably pop off again. If there is no problem there and you can select 5th gear, and then only later does it "pop out" of gear, then the spline lock rings have worn where the mating surfaces of each spline tip don't provide a positive "lock" when under power. Some folks think that when a transmission "pops out" when driving, it is the syncronizers. This is never true. (Even Click and Clack get this one wrong continuously.) The syncronizers are responsible for clashing gears during the gear selecting action.
A transmission rebuild is in order if the thing pops out of gear. Good luck.

run the fault codes
check the transmission actuator and vacuum hoses

You're 5th gear syncro has just gone out. It keeps your shift forks and slider gear from popping off. It also makes it possible to shift the gear in. It's going to take a rebuild of the transmission to fix this problem.

WELL IT SOUND LIKE YOUR TRANS IS GOING DOWN YOU NEED TO LOOK AT TRANS FLUID TO SEE IF IT IS CLEAR LOOKING OR IS IT LOOK LIKE METAL MAY BE IN IT DRAIN A LITTLE IN A PAN THE LOOK AT IT IN SOME LIGHT AND SEE IF IT LOOKS LIKE GOLD FLAKES OR SHING METEL IF SO TRANS HAS INTERNAL ISUSES

This is common for that transmission, it will eventually lead to 5th gear POPOUT, where it will actually pop itself out of 5th gear... I would get a second opinion to be sure, but looks like a rebuild is near maybe.. :(

i had same problem it is your cam positioning sensor

Dear javatrader: There are very few solutions to this problem. The fact that you had mentioned 5th & Reverse, tells me that you problem is has two possibilities. Both relate to the same component.
The shift fork for Fifth gear and reverse are the same as well as the hub which the fork fits over.
When you Move the stick shift, it moves one of 3 rails in the transmission of which one is 5th and reverse. The hub is what locks the transmission in gear. The gears are what are referred to as synchromesh. This means that when you shift from gear to gear, it makes it possible to easily make the transition without the gears grinding while the car is in motion. The synchros are in fact, kind of a "BRAKE" for the gears so that when you go to shift into that gear, the synchronizing ring, slows the gear down enough to match the speed of the counter gear allowing it to engage with it, without grinding. As the hub slides into gear, there are spring loaded "KEYS" which are small pieces of steel about 1/2 inch long, 1/4 inch thick and 1/4 inch wide with a little hump in them to push up into a small cavity machined into the hub when it slides over it, thus locking the gear into place until you pull the stick to move it out of place. If a key pops out, it could cause the gear to stick, not allowing you to pull the hub back because the key has popped out at an angle which prohibits the hub from sliding over it.
Another possible senario: The fork is secured to the shift rail with a part called a "Roll pin". If this part shears, the car will be stick in what ever gear it was in at the time the pin sheared. If the pin shears, the stick will still move out of 5th gear position but the transmission won't.
This problem, unfortunately is not one a layman can fix. This is best left to a professional.
Good luck......If you are pleased with my answer, please write in, that you are satisfied with my answer. I am new in this "FIXYA" group and need more people responding to work my way up the ranks.