NEVER bump start the van in R (or G)
or this can easily happen

not exactly fixable

the reason it happens is that you are putting the weight of the van (say 2 tonnes), via the two axles through a 3:1 reduction gear ( ie multiplying the torque load) onto a gear that is running on a shaft that is supported by only 6mm of case material which is a weak spot

VW/Steyr could have made the case stronger there but then the next weakspot would have given, in this instance that gave too, the end of the main intermediate reduction shaft/gear (it's all one thing and muckle as a muckle thing, running in the biggest and strongest bearing in the whole box) has broken the support for it's end needle bearing

the engineers amongst you can work out the forces involved but the damage I think says volumes, it's a lot of force and "she cannae take it captain"
use first gear if you have to bump, it's big and strong and right next to the pinion bearing so the axial forces on the pinion shaft are the least , and if it doesn't start first bump then go and get a jump pack, another vehicle with some jump leads or fix the fault that stopping it starting readily
this customer is now facing a bill for nearly 1/2 of what he paid for the whole van
when it happens the box drops all it's oil in a matter of minutes and if you continue driving you'll destroy the box and could be facing a rebuild cost well in excess of £2k, and some parts are getting very hard to source and the prices are rising due to scarcity
also the diesel boys should note that the cover plate (that broken in 2 thing bottom right of first picture) to the reverse idler gear isn't very well protected so if you are taking heavy impacts at the back stop and check regularly cos it's easy to bust a bolt out of the case or crack the plate and also loose your oil. The Petrol one isn't immune to similar damage but because of the different engine bash bars is better protected; I'd say that originally the syncro was only going to be petrol but that demand and the change in fuel usage and especially demand from the military/utilities etc.. meant that they came up with the diesel version, because who ever signed off the diesel engine guard for production didn't really understand the concept of protection imho - there are additional protective plates for the diesel for sale on german ebay and some have made their own, if I did diesel I'd have some additional protection on there because I've seen a good few broke or damaged in this way.
Before driving long distance after heavy off roading check to see you aren't dropping gear oil first, say when you come out of the pub before driving home, otherwise the first you'll know is when the box siezes on the motorway
This isn't to put peeps off using the vans like we do, just a case of forewarned is forearmed and be prepared
and ENJOY