Mast Noisy When Lifting And Lowering - JLG 15MVL Series Service Maintenance Manual

Mast Noisy When Lifting And Lowering

Overview Of Procedure
This procedure examines components of the mast itself and as well as it's lifting components for dirt, debris, proper lubrica-
tion and operation.
STEP
1. Do slide pads and slide pad channels need to be cleaned of dust, dirt, or
other debris?
2. Do mast chains need to be lubricated per JLG specification in the Service
Manual?
3. Are the chain/cable sheave wheels dry and need lubrication?
Note: Plastic wheels will howl on the sheave pin when they are dry. Sheave
wheels may seize to the sheave pin and the pin may turn in the pin retainer
blocks.
4. Are the sequence cables (located on the side of mast) chattering when the
springs are compressed?
Note: This noise is normal at the sequence cable sheave wheels when the
mast is completely lowered. However if the sequence cable chattering is
happening no matter what position the mast is in, it could be a result of the
mast being shimmed to tight or dirt and debris in the slide pad channels
causing the mast to be tight.
5. Is the bore of the lift cylinder dry?
6. Are the bearings in the lift pump motor and pump drive worn?
7. Are the hydraulic lines vibrating together?
8. Check if the pump motor is loose to it's mounting plate.
9. Hydraulic oil could be cavatating inside the pump.
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Table 6-46. Mast Noisy when Lifting and Lowering.
ACTION
– JLG Lift –
SECTION 6 - TROUBLESHOOTING
SPEC YES
— Clean Pads and
Channels
— Lubricate as
Required
— Lubricate or
Replace Sheave
Pins and Wheels
— Clean Slide Pads/
Channels or Re-
shim Mast per Ser-
vice Manual
— Replace Packing or
Lift Cylinder
— Repair or Replace
Pump
— Adjust the Position
of the Lines
— Tighten pump
mounting
fasteners
— Repair or Replace
Pump
NO
Go to Step 2
Go to Step 3
Go to Step 4
Go to Step 5
Go to Step 6
Go to Step 7
Go to Step 8
Go to Step 9
—
6-41