TRUCK SERVICE MANUAL
A transfer case is a gear box located between the main
transmission and rear axle.' Its purpose is to transfer power
from the transmission to the front driving axle as well as the
real driving axle.
The transfer case incorporates a front axle declutch which
is used to drive the front axle whenever the vehicle is used on
off-road operations or operated on steep grades.
The transfer case also provides an extra gear reduction
(Lo) in the vehicle power train.
The TC-155 and TC-156 transfer cases are four shaft
clover-leaf type, two-speed units. The case contains constant
mesh helical and spur gears with the shafts supported by
roller and ball bearings.
Disassembly of Transfer Case
After removing the unit, thoroughly clean the exterior
portion before proceeding with the disassembly.
Remove drain plug from the bottom of unit and drain
Remove nuts and take off all yokes or flanges.
Remove capscrews and lockwashers, and pull off the
power-take-off assembly, or rear cover if PTO is not
used (Fig. 3).
Remove capscrews and lockwashers and lift off
cover and gasket (Fig. 4).
Remove detent balls and springs.
Cut lock wire and loosen shift fork set screws.
Pull both shift shafts out through front of case, if
possible (Fig. 5). Otherwise, use a soft metal drift
and drive shafts and expansion plugs out through
rear of case.
Remove oil seals from front of case, if necessary.
Lift out range shift fork and declutch fork.
10. Remove front output shaft bearing cap and gasket.
Pull shaft and declutch collar from case (Fig. 6).
CTS-2048Q Page 4
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