The clutch does not stay engaged (sorry I made a mistake it is a 1996 jetta(standard) not automatic) put it in low gear and step on the gas 3 seconds or so later it goes off , the transmission does not stay engaged, step on the clutch again without changing gear at all it works again then it comes off again 3 seconds lateror so.

SOURCE: tdi clutch pedal pushed all the way down but hard to shift gears

Check your clutch fluid level, sometimes a seperate reservoir (drivers side on firewall), some clutch systems take fluid from the brake system (check brake fluid). If thats ok then the clutch slave may be failing.
If the clutch fluid is low refill it and check for leaks (or just wait till the symptom comes back). If it's happens often then theres a leak in the line or the slave somewhere.

SOURCE: how to remove transmission , how to replace reverse gear?

Are you sure that it is gone? make sure the all the bushing on the transmission are good it maybe that it is not able to go all the way in gear. If you do need to take it out get a good manual "Bentley" are the best it will show you the inside of the transmission too. Haynes are also good but not for working on the transmission it self

SOURCE: jetta clutch won't engage.help please!

Sounds like improper assembly or wrong parts?

SOURCE: 2001 Jetta automatic - won't up-shift

Hi ,
I have a 2002 hetta and i had same problem. The problem is with the N92 selenoid. My machanic changed it last week and now everything is normal.
Check this forum.
http://forums.vwvortex.com/zerothread?id=4188370&page=1
Good luck,
Sam.

SOURCE: does my 1996 vw jetta have a clutch slave or some

The 2.0 liters has a self adjusting clutch cable.