Land Rover Defender V8i Workshop Supplement Rover Manual

AUTOMATIC GEARBOX
1
DESCRIPTION AND OPERATION DESCRIPTION
The automatic transmission is a specially tailored version of the ZF 4HP22, used by many manufacturers of high
performance vehicles.
A three element torque converter delivers the power to a four speed epicyclic transmission. First, second and third
gears are reduction ratios but fourth is an overdrive gear for high speed cruising. A direct drive clutch, integral with
the torque converter operates to engage fourth gear.
The gear selector has seven...

44AUTOMATIC GEARBOX
2
DESCRIPTION AND OPERATION Power flow
1st gear D selected
With D selected 1st gear engaged, clutches 4 and 11 are operative. The front planet gear carrier of gear set 9 is
locked against the housing through freewheel 15 when the engine is pulling but freewheels when the vehicle is
coasting. Epicyclic gear set 10 rotates as a solid unit with the front planet gear carrier. In selector position 1 with
1st gear engaged, clutch 8 operates to prevent the loss of drive on the overrun...

AUTOMATIC GEARBOX
3
DESCRIPTION AND OPERATION 3rd gear D selected
Clutches 4, 5, 7 and 11 are engaged. Freewheel 15 and 16 are overrun. Epicyclic gear set 9 and 10 rotate as a
solid unit at a ratio of 1:1.
4th gear D selected
Clutches 4, 5, 7 and 12 are engaged. Freewheel 14, 15 and 16 are overrun. Epicyclic gear set 9 rotates as a solid
unit. The hollow shaft with the sun wheel of epicyclic gear set 10 is locked.
Above a predetermined road speed, clutch 2 locks the gearbox power input direct to the...

44AUTOMATIC GEARBOX
4
DESCRIPTION AND OPERATION Reverse gear
Clutches 5, 8 and 11 are engaged. Since the front planet gear carrier of epicyclic gear set 9 is locked, the direction
of output-shaft rotation is reversed. Epicyclic gear set 10 also rotates as a solid block. 

AUTOMATIC GEARBOX
1
FAULT DIAGNOSIS ZF AUTOMATIC GEARBOX
Before referring to fault symptoms, carry out initial
static checks first:
INITIAL STATIC CHECKS
Check start positions P & N only........................................................
Reverse lights R only..................................................................
Gear engagements N-D,N-3,N-2,N-1,N-R..........................................................
Full throttle Engine switched off, check full travel at engine and...

44AUTOMATIC GEARBOX
2
FAULT DIAGNOSIS ROAD TEST PROCEDURE
Follow the procedure given commencing each test,
from a standing start, on a level road, in good weather
conditions.
ROAD TEST 1 = CHECKS 1-2-3-4-5-6-7-8
D SELECTED KICKDOWN START FROM REST
CHECK 1
Check for clutch squeal and slip. Check pressure is
10.3 bar (150 lbf/in
2).
CHECK 2
Check 1st to 2nd upshift speed and quality. Pressure
should fall to 8.3 bar (120 lbf/in
2).
CHECK 3
Check 2nd to 3rd upshift speed and quality. Pressure
should fall to...

AUTOMATIC GEARBOX
3
FAULT DIAGNOSIS ROAD TEST 3 = CHECKS
12-13-14-15-16-17-18-19-20-21-22-23
D SELECTED FROM REST
LIGHT THROTTLE START
CHECK 12
Check 1st to 2nd upshift speed and quality.
CHECK 13
Check 2nd to 3rd upshift speed and quality.
CHECK 14
Check 3rd to 4th upshift speed and quality.
NOTE: This shift is usually very difficult to
detect but can be confirmed by a 200
rev/min drop in engine speed.
CHECK 15
Check speed and quality of shift into direct drive
clutch, confirmed by 300 rev/min drop in...

44AUTOMATIC GEARBOX
4
FAULT DIAGNOSIS AUTOMATIC GEARBOX ASSEMBLY
1. Gearbox assembly
2. Inhibitor switch assembly
3. Control unit assembly
4. Filter and sump assembly 

AUTOMATIC GEARBOX
5
FAULT DIAGNOSIS 1. Torque converter housing assembly
2. Gearbox pump and casing assembly
3. Governor and adaptor housing assembly