I did successfully rebuild my 5 speed, which had a snapped mainshaft, caused by a totally disintegrated roller bearing which allowed the mainshaft to move about way more than it was designed to! it can be done, but just be aware that it is a fairly tricky task, even if you have done a few simpler boxes before, like i had, and even with the right gear, and a lot of photo copies from a genuine vw manual, which i wouldn't attempt it without. stubborn-ness and lack of funds made me see the job through and i now have a sweet gearbox apart from a very slight whine from 3rd which is the only gear that i didn't replace the bearing for, as it looked ok, but to be honest, if i had to do it all again, i'd get it looked at by someone reputable, like mr talbot, as i had a bad experience with a box from a supposed vw 'specialist' selling what they claimed was a 'rebuilt' gearbox which was basically a pile of crap. before deciding to rebuild my own and before i had heard of Aidan's services, i paid 300quid for a supposedly rebuilt 5 speed which turned out to jump out of 5th, and whine like a biatch in neutral, leaked oil massively too. eventually got my cash back, obviously not all traders are like this, but the whole experience took weeks of faffing about and nearly led to me giving up and selling the van. DIY rebuilds can be done, but access to the right equipment, and lots of time and patience are needed, a known good second hand unit, if you can get one, or better still a proper, quality rebuild from a reputable chap like Aidan are the way to go in my opinion. but good luck if you decide to go for it, and tackle it yourself.
good luck with it mate whatever you decide to do.
