FAN AS 2424251 - Caterpillar

Limited Slip Differential 938
The limited slip differential is a locking differential. The limited slip differential is designed to provide equal power to both wheels. Equal power is provided to both wheels until the ground conditions cause a variance in traction between the left wheel and the right wheel. The limited slip differential transfers lost power from the wheel with the least traction to the wheel with the most traction.The limited slip differential is a direct replacement for the standard differential. The limited slip differential is available in the rear axle group only.
Illustration 1 g00280829
Typical Example of a Limited Slip Differential
(1) Housing
(2) Thrust washer
(3) Clutch pack
(4) Pressure ring
(5) Bevel gears
(6) Pinion gears
(7) Pinion gears
(8) Pinion shafts
Illustration 2 g00280828
Locking Ratio
(4) Pressure ring
(8) Pinion shaft
(9) 45 degree angle When the wheels have equal traction, the limited slip differential sends an equal amount of power to both of the wheels. The limited slip differential is similar to the function of the standard differential. One wheel begins to turn faster than the other wheel if there is a loss of traction. When loss of traction occurs, the internal forces that are present between shaft (8) and pressure rings (4) will react on 45 degree angle (9). The internal forces push pressure rings (4) against clutch packs (3). The torque of the clutch pack limits the loss of traction to the wheel that is turning faster.The locking effect is due to the internal friction of the differential. This effect is produced by two clutch packs (3) which are arranged symmetrically in the differential housing. In a standard differential, one wheel can be held in position when the engine is running and a gear is engaged. The other wheel will turn faster. In the limited slip differential, the above procedure would be more difficult because of clutch packs (3). The above procedure will become more difficult as power increases.The limited slip differential is identical on the left side and the right side of two pinion shafts (8). The limited slip differential contains the following components: four thrust washers (2), two clutch packs (3), two pressure rings (4), two bevel gears (5) and four pinion gears (7).The inside splines of bevel gears (5) are connected to the sun gears for the final drives. The outside splines of bevel gears (5) are meshed with the inner friction discs in clutch packs (3). The bevel gears (5) send the power through the sun gears and to the final drives.Housing (1) is fastened to the ring gear. Housing (1) has inner grooves which hold the outer discs. The outer discs are in clutch pack (3). The clutch pack also has inner discs between the outer discs. The inner discs are splined to the side gears. Pressure rings (4) also fit in the same grooves. The actuator housings are held with the discs from moving radially. Bevel gears (5) fit into pressure rings (4). Pinion shafts (8) also fit into pressure rings (4). The pinion shafts lie in the 45 degree notches