axle SSANGYONG MUSSO 2003 Repair Manual

Page 1093 of 1574

5D2-4 TRANSFER CASE (TOD)FUNCTION DESCRIPTION
TOD System Select Mode (4H and 4L) 4H is the mode when drive normally of which gear ratio is 1:1 and 4L mode distributes power to front and rear wheels 50:50 of which gear ratio is 2.48:1.
TOD System Function (select 4H mode) TOD system controls clutch mechanism to comply with rotation in front and rear propeller shaft and if its difference exceeds the permissible range, corresponding power is distributed into front wheel through EMC (Electro-MagneticClutch). Hall effect sensor signals speed on front and rear propeller shafts going through with TOD control unit.
Transfercase clutch coil is activated by variable current on exceeding difference of speed in front and rear propeller shafts.
Function of 4L Mode When select 4L mode, EMC is locked to apply maximum torque into front and rear propeller shafts. Shift motor rotates also 4L position by rotation of cam thus propeller shaft torque changes from 1:1 to 2.48:1 by planetarygear set.
Shift Motor It locates backside transfer case, which drives rotary helical cam. When mode select switch changes to 4L, shift fork is on position for 2.48:1 by rotation of helical cam.
Transfer Case
TOD transfer case distributes power into front and rear axle by operation of 4H/4L switch and shift motor. Shifting 4H to 4L, is performed towards reducing HI-LO collar by means for connection HI-LO shift fork with
output shaft in order to join with planetary gear. Torque transmits input shaft then sun gear rotating front planetary
gear. Front planetary gear join with output shaft and drives LO position.

Page 1100 of 1574

TRANSFER CASE (TOD) 5D2-11
4. Electric Shift Default ModeIf the motor fails to reach its destination, the TCCU will attempt the following (in order):
a. The TCCU will wait 3 seconds then attempt the shift again.
b. If the second attempt to reach the destination fails the TCCU will wait 3 seconds then attempt to rotate the motor back to the original position. If successful, all future shifts will be inhibited until the Ignition is cycled.
c. If the attempt to return to the original position fails, the TCCU will wait 3 seconds then attempt to rotate the motor to the original position again. If the second attempt to return to the original position is successful, the “4WD CHECK ” lamp will be illuminated, and all future shifts will be inhibited until the Ignition is cycled.
d. If the second attempt to return to the original position fails the motor will be turned off, the “4WD CHECK ” lamp
will be illuminated, and all future shifts will be inhibited until the Ignition is cycled.
TOD TM
System Operation
The TOD TM
System is responsible for distributing torque between the front and rear axles. The TCCU monitors the
propshaft speeds, operating range (High/Low), and ABS activity and then applies a calculated amount of torque tothe front axle by Pulse Width Modulating the current applied to the EMC.
1. Touch-off Torque
The minimum EMC Duty Cycle is based on the vehicle speed and throttle positionThe TCCU receives the TPS signal from the following sources:On vehicles equipped with CAN, the TCCU receives the TPS signal from the CAN bus.
2. When Slip Detection
The TCCU continuously monitors the front and rear propshaft speeds to detect wheel slip.
3. Wheel Slip Control When wheel slip is detected the TCCU controls the EMC duty cycle as necessary until the wheel slip is reduced
below the allowable limit. The EMC Duty Cycle will then be reduced to the Touch-Off value.
4. Brake/ABS Strategy When the ABS System is active, the EMC Duty Cycle is set to a fixed duty cycle (30%) to aid in braking without counteracting the ABS System.
5. 4L Strategy When the system is operating in 4L, the TCCU continues TOD TM
(operation provided that the propshaft speed is
below 175 rpm (5220 pulses/minute)). When the speed increases above 175 rpm, the EMC Duty Cycle is set tothe maximum value (88%) which applies the maximum available torque to the front axle.

Page 1108 of 1574

TRANSFER CASE (TOD) 5D2-19
ClassificationEngine Type
Transmission/Vehicle Type Axle Ratio
Tire Size
Coding Required
1. Replacement of TOD control unit.
2. Adjustment by input error.
3. Change of tire specification.
Items
Gasoline Engine (E32) 661 Diesel Engine
661LA Diesel Turbo Engine
662 Diesel Engine
662LA Diesel Turbo Engine Manual Transmission
Automatic Transmission MUSSO
KORANDO 3.734.554.895.38 5.86
P215 P235P255P275
Coding Method
1. Check and record engine type, axle ratio and tire size.
2. Ignition “OFF ”.
3. Connect SCANNER with diagnosis connector in engine room.
4. Ignition “ON ”.
5. Read the current memorized specification in TOD control unit.
6. Compare memorized specification with the checked record. If not matched, perform a coding.
7. Read again memorized coding specification in TOD control unit for confirmation of coding.
8. Check coding specification whether it matches with vehicle or not. If not, perform a coding again.
Coding items

Page 1135 of 1574

5D2-46 TRANSFER CASE (TOD)
23. Remove the internal snap ring from the planetary carrierand separate the front planet from the input shaft.
24. Remove the external snap ring from the input shaft. Place the input shaft in a vise and remove the bearing. Remove
the thrust washer, thrust plate and the sun gear off theinput shaft.
25. Inspect the bushing and needle bearing in the end of the input shaft for wear or damage. NoticeUnder normal use, the needle bearing and bushing should not require replacement. If replacement is required, thebushing and needle bearing must be replaced as a set.
26. If replacement of the needle bearing and bushing is required, press the bearing and bushing is required, pressthe bearing and bushing out as follows:
a. Position the input shaft on Axle Bearing/Seal plate,andusing Pinion Bearing Cone Replacer as a spacer.
b. Insert Input Shaft Bearing Remover into the input shaft so it is resting on top of the bearing cage.
c . Tighten the actuator pin until it stops, then press the bearing and bushing out together. 6 Input Shaft
8 Bearig
01 Pinion Bearing Cone Remover
02 Compress the Dowel
27. If required, remove the front yoke to flange seal by prying and pulling on the curved-up lip of the yoke to flange seal. Do not damage the bearing, bearing cage or case.
28. If required, remove the internal snap ring retaining the front output shaft ball bearing and remove the bearing.

Page 1136 of 1574

TRANSFER CASE (TOD) 5D2-47
Assembly Procedure Assembly
Before assembly, lubricate all parts with Automatic Transmission Fluid or equivalent.
1. If removed, drive the bearing into the front output case bore.Drive the bearing in staight, making sure it is not cocked in the bore. Install the internal snap ring that retains the bearing to the front case.
2. If removed, install the front yoke to flange seal in the front case bore.
3. If removed, install the yoke to flange seal into the mounting adapter bore.
4 Sun Gear
5 Thrust Plate
6 Input Shaft
7 Thrust Washer
8 Bearing
9 External Snap Ring
10 Internal Snap Ring
4. If the input shaft needle bearing and bushing were removed,
install a new bearing and bushing as detailed in the following steps: Press a new needle bearing, then a new bushing in the input shaft as follows:
a. Position the input shaft on Axle Bearing/Seal Plate or equivalent, and Pinion Bearing Cone Replacer as a
spacer.
b. Press a new needle bearing into the end of the input shaft until it seats in the input shaft.
c. Press in a new bushing.
5. The recessed face of the sun gear and the snap ring groove on the bearing outer race should be toward the rear of thetransfer case. The stepped face of the thrust washer shouldface toward the bearing.
Slide the sun gear, thr ust plate and thrust washer into
position on the input shaft. Press the bearing over the input shaft. Install the external snap ring to the input shaft.

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