Power Jacks C-Series - Manual (Page 23)

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6
Maintenance
6.3.4 Check all bolted joints/couplings for wear, deformation or corrosion and tighten them down fully
without over tightening.
6.3.5 A periodic check of backlash between lead screw and worm gear (translating screw jacks) or
lead screw and nut (rotating screw jacks) is recommended to check wear on internal threads
of worm gear. Backlash in excess of 25% thread thickness indicates that a replacement will be
necessary to replace the worm gear / nut assembly.
6.3.6 If driven by an electric motor check the power absorption and voltage against the nominal
values given on the motor’s nameplate.
6.3.7 The gearbox section of the C-Series screw jack operates with a maximum case temperature of
90°C. If this temperature is exceeded Power Jacks should be consulted.
6.4 Repair of Power Jacks C-Series Screw Jacks
6.4.1 Power Jacks recommend that a C-Series screw jack is returned to Power Jacks for repair. A full
inspection and repair service is available.
6.5 Rebuild Procedure
Power Jacks recommend the following procedures for assembly and disassembly of a C-Series screw jack.
6.5.1 Tag critical parts to facilitate reassembly.
6.5.2 Place all screws, washers and other small fixing components in a tagged bag/box with the
associated product on which they are to be used referenced on the tag.
6.5.3 Mark mating surfaces to ensure proper meshing.
6.5.4 Clean and lubricate all parts as required.
6.5.5 All seals must be replaced when rebuilding.
6.5.6 All screws, washers and other small component parts must be replaced if damaged in any way.
6.5.7 Replace damaged or “frozen” lubrication fittings with new ones.
6.5.8 General Dis-mantle & Rebuild Procedure
6.5.8.1 Remove the lead screw from the screw jack body.
6.5.8.2 Unscrew the fasteners fixing the shell cap.
6.5.8.3 Unscrew the shell cap and release the thrust bearings and worm gear.
6.5.8.4 Remove one circlip and gently tap out the worm shaft from the opposite side with a soft mallet
(e.g. rubber mallet).
6.5.8.5 Inspect and replace parts for wear or damage.