JLG 1250AJP Service Manual - Manual (Page 74)

SECTION 3 - 1CHASSIS & TURNTABLE
3-26 – JLG Lift – 3121171
TROUBLESHOOTING The following table is provided to help locate problems in
the gearbox.
Disassembly Information
It is also important that this procedure is undertaken in a
workshop that is equipped with the proper tools. As well
as normal workshop tools it will be necessary to use spe-
cial tools that can be made (see special tools attachment)
or may be requested from the manufacturer.
Special Tools:
Puller...............................................Code/: 6689960240
Tool for lifetime seal assembly........Code/: 6689960300
Puller for brake disassembly..........Code/: 6689960310
Torque multiplier............................Code/: ATZ.09.016.0
To be able to produce these special tools refer to Figure 3-
20. thru Figure 3-23.
It is important to strictly adhere to all the procedures for
disassembling and reassembling the gearbox. Proceed
with these instructions using all the necessary safety mea-
sures, for example:
1. Plug all the Hydraulic ports on the gearbox to avoid
the introduction of any foreign particles in the circuit
and the gearbox.
2. Making sure that the coupling surfaces are not dam-
aged.
3. Handle with care so as to be sure that there are no
risks for personnel safety and to guarantee the reli-
ability of the gearbox.
4. Making available a work area that is in line with work
and health safety in the workplace guidelines.
Disassembly
NOTE: Below are all the steps to follow during Disassembly
and Assembly. Numbers in brackets in the text corre-
spond to the references in the exploded view.
Initial inspection can be made without disassembling the
hub from the machine. Before wheel drive disassembling,
make sure that the oil is drained from the hub.
Unscrew and remove the nos. 2 screws M12, grade 8,8,
and remove the hydraulic motor and its O-ring seal (48).
Table 3-5. Troubleshooting
Symptom Causes Remedies
External oil leakage:
From the lifetime seal a) Lifetime seal damaged a) Replace lifetime seal
From the end cover a) O-ring seal damaged a) Replace O-ring seals
From the plugs a) Plug seal damaged a) Replace plug seal
b) Plugs or screws loose b) Tighten the plugs/screws
Too much noise:
Hydraulic noise (during the slowing
down of the motor speed) a) Hydraulic circuit malfunctioning a) Verify hydraulic circuit
Inside the gearmotor (reductions) a) Internal damage a) Check the gearbox
Other:
Overheating a) Insufficient oil level a) Check the oil level and refill if necessary
b) Hydraulic oil too warm b) Check the hydraulic circuit
c) Brake not fully released c) Check brake release pressure
Parking brake malfunctioning
Insufficient braking torque a) Brake discs worn a) Replace brake disc pack
b) Damaged parts b) Check brake components
Wheel Locked a) Parking brake locked a) Check the complete brake release
b) Mechanical components damaged b) Replace damaged parts