Mitsubishi Engine S6S description of the catalogue:

Mitsubishi S6S Engine Service Manual.

S6S Diesel Engine FD35 thru FD50 / FD60 thru FD70
S6S Diesel Engine For use with FD40K, FD40KL, FD45K, FD50K, FD60, FD70, Chassis Service Manual. serial 28620-up

This service manual covers S6S Diesel Engine of Mitsubishi Forklift Trucks and gives detailed maintenance and repair information. The instructions are grouped by systems to serve the convenience of your ready reference.
Long productive life of your forklift trucks depends to a great extent on correct servicing – the servicing consistent with what you will learn from this service manual. We hope you read the respective sections of this manual carefully and know all the components you will work on before attempting any work.
All descriptions, illustration, specifications, and serial numbers in this manual are effective as of the printing date of this manual. Mitsubishi reserves the right to change specifications or design without notice and without incurring obligation.