Land Rover Defender: Component Location, Overview
COMPONENT LOCATION
COMPONENT LOCATION - 1 OF 1
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- Twin speed transfer case
OVERVIEW
The twin speed transfer case is full time, permanent all wheel drive unit, with 50/50 torque distribution to the front and rear driveshafts. The transfer case is identical for all engine derivatives and supports the following features:
- Permanent all wheel drive with a bevel gear center differential, providing a 50/50 torque split.
- Selectable high and low range for optimum on road and off road performance.
- A pre-loading function, increasing locking torque with increased driving torque.
- A slip controller to increase locking torque under off road conditions and decrease locking torque for optimum comfort, for example, during parking.
The twin speed transfer case is located under the vehicle and is installed on the cross member, behind the automatic transmission.
The input torque is equally distributed through a bevel gear center differential. The twin speed transfer case equipped with an electronically controlled locking and torque-biasing device. The twin speed transfer case can provide an optimal torque distribution to each wheel in all driving condition. Electronically controlled locking and torque-biasing device detects wheel slip through various vehicle system inputs to the Transfer Case Control Module (TCCM).
Electronically controlled locking and torque-biasing device locks the differential accordingly. The locking torque is applied through a multiplate clutch assembly.
A planetary gear set, located in the differential assembly, allows the driver to select high or low range. In low range, the planetary gear set provides a ratio of 2.93 : 1. Low range gives the vehicle an extremely low crawl speed for off road driving and trailer towing. High range is a direct drive from the transmission output shaft and provides a 1 : 1 ratio.
The oil used in the transfer case is specially developed and contains unique additives, which enhance the transfer case operation. No other oil must be used in the transfer case.
A unique type of grease, grease Weicon TL7391, must be applied to the transfer case input shaft spline when installing the transfer case.
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- Input shaft spline
READ NEXT:
Description
TRANSFER CASE EXPLODED VIEW
Synchronization spring (quantity 3)
Spring bracket
Multiplate clutch ( 10 friction plates, 10 steel plates)
Synchronization cup
Drum clutch
Plate clutch pack
Synch
Operation
High range operation
In high range, the torque output from the automatic transmission is passed to
the transfer case input shaft. The
position of the shifting sleeve couples the input shaft directly
Transfer Case - Diagnosis and Testing
DIAGNOSIS AND TESTING
PRINCIPLE OF OPERATION
For a detailed description of the transfer case system and operation, refer
to the relevant Description and Operation
section of the workshop manual.
INSP
SEE MORE:
Warning Devices - Control Diagram
CONTROL DIAGRAM - 1 OF 6 - BLIND SPOT ASSIST
A = HARDWIRED: U = PRIVATE CAN BUS: AZ = HS CAN BODY SYSTEMS BUS: BA= HS
CAN HUMAN MACHINE
INTERFACE (HMI) SYSTEMS BUS: BL = HS CAN UN SYSTEMS BUS.
BCM/ GWM
AAM
IPC
HUD
PDM
DDM
Approaching vehicle lamp - Left door mirror
Approaching vehicle lam
Battery Diagnostics - 12 Volt Midtronics EXP-1080 JLR Hand-Held Battery
Diagnostic Tool
DIAGNOSIS AND TESTING
PRINCIPLES OF OPERATION
For a detailed description of the battery system and operation, refer to the
relevant Description and Operation section
of the workshop manual. REFER to: Battery and Cables.
INSPECTION AND VERIFICATION
CAUTION:
Diagnosis by substitution from a donor veh
