Yes Dean, repaired plenty of Foden gearboxes and we tried to keep one built up ready to swap over. The front mainshaft bolt used to shear off, also the rear mainshaft nut used to loosen and then the epicyclic gear assembly would float about wrecking the shaft. Fodens modified those though and cured that problem. On the later ones they incorporated an air operated clutch stop on the layshaft instead of on the primary shaft and the two studs regularly sheared off and let the layshaft drop, I reckon we rebuilt a box most weeks and kept all the parts in stock ready. The two we had with 220 Rolls engines used to crack the bellhousings every few months. I still have the ‘special tool’ for setting up the selectors in my toolbox: a short piece of 1" square steel box section. I doubt that I will ever rebuild another though! 
Pete.