Lull 944E-42 Service Manual User Manual

Page 184

Electrical System

9-26

944E-42

Note: If the transmission is not shifting properly, the
transmission shift control switch (travel select lever),
wiring harness or transmission shift solenoids should be
checked in order to determine which component is
defective. Specific information to determine which travel
position and corresponding component is not responding
can be found in the detailed transmission service
instructions (covering repair, disassembly, reassembly
and adjustment information) are provided in the
ZF 4 WG-98 TC Repair Manual P/N 5871 135 002
(JLG P/N 8990455). and can be obtained by calling your
local Authorized Service Department.

The transmission should be checked, serviced and
repaired only by experienced service technicians who are
aware of all safety instructions and particular component
features.

Note: Contact your local authorized Service Department
if internal transmission repair is required during the
warranty period.

a. Travel Select Lever and Wiring Harness Testing

Note: An assistant will be required to be seated and
operate the travel select lever in order to perform the
following test.

1. Disconnect the wiring harness plugs from all of the

transmission solenoid valve bodies. Turn the ignition
switch to the run position.

Note: In order to perform the solenoid test, the Parking
Brake Switch must be in the OFF position.

2. Have an assistant place the transmission lever in the

position that is not functioning correctly.

3. Check the harness side plug connector plugs on the

active solenoids corresponding to the direction and
gear that has been selected with a DMM for battery
voltage. Refer to the chart that follows. Place the
negative (-) lead on pin B (ground) (13) and the
positive (+) lead on pin A (14), and test for battery
voltage. If battery voltage is not present on any of the
pins that have been tested, the wiring harness is
suspect and should be replaced. If battery voltage is
present, the harness is functioning properly.

Note: The following chart shows which solenoids are
active with any given selection of the transmission lever
and gear select position.

b. Transmission Solenoid Testing

Inspect each solenoid connector plug (15). Test across
the two pins inside the connector for continuity and
shorting. Each solenoid should have between 10.0 and
15.0 ohms of resistance when testing with an ohmmeter.

Replace a defective solenoid valve. Refer to Section
9.11.8, “Transmission Solenoid Valves.”

c. Removal

1. Park the machine on a firm, level surface, level the

machine, fully retract the boom, raise the boom,
place the transmission control lever in
(N) NEUTRAL, engage the park brake and shut the
engine OFF.

2. Place a Do Not Operate Tag on both the ignition key

switch and the steering wheel, stating that the
machine should not be operated.

3. Properly disconnect the batteries.

MU3941

Solenoid Valve

Callout

(5)

(6)

(7)

(8)

(9)

(10)

Driving

Direction

Speed

Forward

First

•

Forward

Second

•

Forward

Third

•

Forward

Fourth

•

Reverse

First

•

Reverse

Second

•

Reverse

Third

•