TM 5-3805-258-24-1
S Y S T E M S
O P E R A T I O N
POWER TRAIN
D I F F E R E N T I A LS
Shims (23) are used to make an adjustment to the
tooth contact (wear pattern) between pinion (24)
and ring gear (17).
Rings (3 and 20) are used to make an adjustment
to the free movement (backlash) between pinion (24)
and ring gear (17). Rings (3 and 20) are also used to
make an adjustment to the bearing preload of bear-
ings (2 and 21).
The inside components of the differential get their
lubrication from oil thrown around inside the differ-
ential. Flat surfaces on spider (14) let oil go to bear-
ings (15). The supply for lubrication oil is a reservoir
in the axle housing.
OPERATION
Straight FORWARD or REVERSE
When the machine moves in a straight direction
with the same amount of traction under each drive
wheel, the same amount of torque on each axle holds
the pinions so they do not turn on the spider.
Pinion (24) turns ring gear (17). Ring gear (17)
turns cases (1 and 18). Cases (1 and 18) turn spider
(14). Spider (14) turns side gears (4 and 19) through
pinions (13). Pinions (13) do not turn on the spider.
The side gears turn the axle shafts. The same amount
of torque is sent to each wheel.
This gives the same effect as if both drive wheels
were on one axle shaft.
FORWARD or REVERSE Turn
When the machine is in a turn, the inside wheel has
more resistance to turn than the outside wheel. This
resistance causes different torques on the opposite
sides of the differential. It is easier for the outside
wheel to turn than it is for the inside wheel. The
outside wheel starts to turn faster than the inside
wheel.
Pinion (24) turns ring gear (17). Ring gear (17)
turns cases (1 and 18). Cases (1 and 18) turn spider
(14). Spider (14) turns side gears (4 and 19) through
pinions (13). Since it takes more force to turn one
side gear than it does the other, pinions (13) turn
around the spider. As the pinions turn, they move
around the side gears. This lets the outside wheel
turn faster than the inside wheel.
The same amount of torque is sent to both the
inside and outside wheels. This torque is only equal to
the amount needed to turn the outside wheel.
Loss of Traction (Wheel Slippage)
When one wheel has more traction than the other,
the operation of the differential is the same as in a
turn. The same amount of torque is sent to both
wheels. This torque is only equal to the amount need-
ed to turn the wheel with the least resistance.
3-53
