I have one Honda SP that has no problem in reverse Norm.

The gearbox durability went down on the VC auto drive and later Victa SP mowers compared with
the 1960s Victa Self Propelled mowers but inferior parts can make more profit in spare parts sales.

A mower mechanic told me the old Rover SP mowers lasted a lot longer than the Victa SP mower when
mower contractors used them day in day out.