Yanmar 4LHA-HTP Operation Manual page 605

Chapter 7 Reduction and Reversing Gear
5. Reassembly
Preassembly of Input Half of Housing
31. Install breather valve (do not overtighten).
BEARING PRELOAD ADJUSTMENT
IMPORTANT: If new tapered roller bearings have been
installed, the preload must be readjusted. If bearing were
not replaced, proceed to the final reassembly section.
NOTE: The required preload of bearings of the individual
shafts is obtained by using shims beneath the tapered roller
bearing cups in the input half of the housing.
NOTE: Shims which have been removed during disassembly
may be reused.
32. Subtract approximately 0.008 in (0.2mm) of shims from
each bearing cup bore. Remove and set aside, but do
not mix up.
A WARNING
Use care in handling housing once it has been heated
with a torch lamp. Severe burns could result. Use special
protective gloves when handling housing.
33. Heat each tapered roller bearing cup bore with a torch
lamp. Insert shims (less those removed) and bearing
cups into appropriate bearing bores. When housing has
cooled (Do Not cool with water), tap bearing cups with a
suitable mandrel to ensure that cups are fully seated.
a - Bearing Cups
b - Torch Lamp
7-2-31
4LHA Serit