JLG 450AJ Service Manual - Manual (Page 89)

SECTION 3 - TROUBLESHOOTING
3120869 – JLG Lift – 3-7
Boom swings erratically in either direction.
Hydraulic system oil low. Replenish oil as necessary.
Lack of lubricant on swing gear or speed reducer
pinion. Lubricate as required. (See Lubrication Chart.)
Swing motor not functioning properly. Repair or replace swing control switch.
Worn or broken teeth on swing gear or swing
motor pinion. Replace gear(s) as required.
Restrictor valves(s) plugged. Clean or replace restrictor valve.
Table 3-2.Boom Assembly - Troubleshooting
TROUBLE PROBABLE CAUSE REMEDY