Allison B 400 - Recording Data; Clutch Pressure Test Conditions

B–2 Copyright © 1998 General Motors Corp.
WTEC II ELECTRONIC CONTROLS TROUBLESHOOTING MANUAL
APPENDIX B — CHECKING CLUTCH PRESSURES
6. Be sure that the transmission has enough fluid for cold operation until an operating temperature
fluid level can be set.
7. Bring the transmission to normal operating temperature of 71–93ºC (160–200ºF). Check for fluid
leaks in the added pressure gauge/transducer lines. Repair leaks as needed. Be sure that fluid level
is correct.
B. Recording Data
1. Use the Pro-Link
®
9000 diagnostic tool, which allows checking of individual range clutch
pressures, with the vehicle stationary. Consult Appendix N or the Pro-Link
®
9000 operating
instructions for Action Request and select Clutch Test Mode. Follow instructions to check clutch
pressures in individual ranges.
NOTE: Check lockup clutch pressure by driving the vehicle in a range where lockup can be obtained. Record
the pressure values at the engine speed and sump fluid temperature values shown in Table B–1. The
lockup clutch is functioning correctly when engine speed and turbine speed values are equal as
recorded from the Pro-Link
®
9000.
2. Consult Table B–1 and locate the transmission model that you are testing.
3. Operate the transmission at the conditions shown in Table B–1 and record engine speed,
transmission sump fluid temperature, main hydraulic pressure, and clutch pressures in the ranges
where a problem is suspected.
Table B–1. Clutch Pressure Test Conditions
Transmission Model/Test
Type
Engine
rpm
Sump Fluid Temp Range Clutches Pressurized
All (except MD 3070)
— Idle Check
580–620 71–93ºC Neutral C5
(160–200ºF) Reverse C3 C5
1C C1 C5
2C (2nd range start) C1 C4
MD 3070 — Idle
Check
580–620 71–93ºC Neutral C5
(160–200ºF) Reverse C3 C5
LowC C3 C6
1C C1 C5
MD (except 3070)
B 300/B 400 —
High Speed
2080–2120 Reverse C3 C5
Neutral C5
1C C1 C5
2C C1 C4
2L C1 C4 LU
3L C1 C3 LU
4L C1 C2 LU
5L C2 C3 LU
6L C2 C4 LU