mac f After reading all the comments in replies , It appears to be a very simple answer you were looking for , but the replies got confused. Perhaps I can enlighten those as to the Australian situation. The Hyster H30-40-50-60H with the Ford 172 engine initially , assembled ( built ) in Australia was designated DOO3S.
D was the series of the forklift ,with the Ford engine. 3 was the pneumatic tyred group
which included the earlier A3 ( YE40- HE50 ) with the Continental F162 engine and B3 ( H30-40-50-60F ) with the Continental G193 engine. S was the letter identifying the city where it was built ( Sydney
Australia ) The Ford 172 was superseded by the Ford 192. The 172 being of 3.9 inch bore and the 192 of 4.13 bore. The engines were identical except for pistons and rings although it would pay to use the 192 head gasket if overboring the 172, which can be bored to the maximum of 4.13 +.020 the same max. as the 192.
Early problems occurred with overheating , which resulted in a new head gasket being produced that blocks off two coolant ports between the head and block.
Back to the model numbers , The H-H series E3S was also built in Sydney.
Likewise the H50-60J was also built in Sydney with the 181 Chev as in the earlier H-H E3S.
The Brazilian machines H40-50K and then the H55N which were imported into Australia by Hyster were E3Y with the Y designating SAO PAOLO Brazil as the build location and fitted with a 151 Chev.

The reason mainly for any excessive oil build up in the bell housing is normally due to scavange scoop problems , such as out of adjustment or broken , very rarely does the hose give problems unless it gets kinked or blocked.