The 1-Ton gearbox was inherited from the IIB Forward Control, and one notable feature is that this design of gearbox incorporated a longer mainshaft with different rear bearing. Many of the transfer box gears were of different design to a “normal” gearbox too. When Power Take Offs were needed on a 1-Ton or a Forward Control they had to be a slightly different design to standard. The most common types for 1-Tons were a hydraulic pump and a drop PTO, both for powering winches. The differences in the PTOs themselves are illustrated below.
The operating fork has a bend to suit the 1-Ton gearbox. For a standard gearbox it is straight. The engagement ring is also a different design for the two types of gearboxes as it can be seen in the photos above.
The bottom PTO is of a different internal design. The 1-Ton version is on the left.
Standard rear PTOs can be made to fit a 1-Ton type gearbox using a spacer. However, a 1-Ton PTO cannot be made to fit a standard gearbox.