Road Test Procedure for Range Rover Classic 44 - ZF Automatic Gearbox Fault Diagnosis
44
AUTOMATIC 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.
ROADTEST 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
bar, 150lbf/in
2
CHECK 2
Check 1st to 2nd upshift speed and quality. Pressure
should fall to 8.2 bar, 120 lbf/in
2
.
CHECK 3
Check 2nd-3rd upshift speed and quality. Pressure
should fall to 6.8 bar, 100 lbf/in
2
CHECK 4
Release throttle to allow simultaneous engagement
4th + DDC. Check shift quality and engine rpm drop of
approximately 500 rpm.
CHECK 5
To proceed to Check 5 release throttle and check
drop out speed of direct drive clutch to 4th.
CHECK 6
Check down shift speed and quality 4th to 3rd.
NOTE: This shift is usually very smooth
and difficult to detect.
CHECK 7
Check downshift speed and quality 3rd to 2nd.
CHECK 8
Check downshift speed and quality 2nd to 1st. Also
difficult to detect.
END OF ROADTEST 1
ROADTEST 2 CHECKS = 9-10-11
D SELECTED FROM REST
FULL THROTTLE START
CHECK 9
Check 1st-2nd upshift speed and quality.
CHECK 10
Check 2nd 3rd upshift speed and quality.
CHECK 11
Check 3rd 4th and direct drive clutch upshift speed
and quality.
NOTE: 4th and the direct drive clutch
engage simultaneously.
END OF ROADTEST 2