With the help of the LR4×4.com forum, we have managed to pull together the Gearbox and transfer box manuals in pdf format for you to download.
R380 Gearbox Overhaul Manual
Defender 90 110 Workshop Manual Book7 LT77s Gearbox Supplement
LT77 GearboxManual
LT 230T Transfer Box Overhaul Manual
LT230 Transfer Box