5th gear gone! Yet again no ECU remap :(

When will this car give me a break? It has to be female...no doubt !

1999 Disco II TD5, manual gearbox, EGR blanked, new clutch, new airsprings, new etc...

Cruising at 70 on the M25 this morning (yes there are stretches where you can get up to those speeds ) when there was a clunk, grinding and the car suddenly decellerated. Pulled over but couldn't find anything obviously wrong. Pulled away again, got up to speed and as I changed into 5th...nothing...no power just some grinidnig noises. Also there is a tinny rattle when accelerating in 2nd and 3rd. Completed journey in 4th gear (a bit noisy) but otherwise ok.

So, what I want to know is how catastrophic this is? Am I looking at a recon gearbox or is it something that can be easily replaced. If, as I suspect it's the former, are there any recommendations? Synchro on 2nd has been non-existent since buying her so may tip the balance towards a recon anyway.

I can't replace the unit myself so gonna need someone to do it for me. Again any recommendations in and around the Crawley area. Btw, clutch was replaced around 2000 miles ago so that shouldn't need replacing.

So once again, just as I was thinking of ringing Mike at DynaChip, the "Bargain" strikes again... Oh what I'd give for 1 clear month without need of an essential fix .

seems like rear part lay shaft snapped,could bev repaired but seems like synchros and bearings need changing as well .i would go for recon ,buts worth doing some home work on prices ,warrenty etc before choosing,

Cheers James,

Have looked into it (Ashcroft Transmission) but really need the car ready before the weekend so limited on options. A local garage are gonna source the box and get it fitted, with oil and VAT for a little over a grand!!!