Joyce BG450D User Manual
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3-4 Maintenance Check
1. Check the pinion shaft for excessive backlash (more than 10% angular). If excessive
backlash is present contact Joyce/Dayton. The unit should be returned to Joyce/Dayton
for service. Only qualified personnel should perform this procedure.
2. Acme threads are the main support members in BG 450 bevel gear jacks. If they wear too
thin, the jack could fail. Determine wear by checking jackscrew endplay at least once per
month. Endplay is the gap between the lifting nut and the acme threads on the jackscrew.
Check the wear more frequently in severe applications.
a. Remove the load from the jack.
b. Make sure sleeve cap set screws are tightened.
c. Mark a reference point on the screw.
d. Move screw upward away from the bevel gear housing.
e. Measure the distance moved from the reference mark.
f.
Record the endplay in a log.
g. To determine if the lifting screw needs to be replaced please contact
Joyce/Dayton with this information as well as the serial number, load, and speed
information.
3. Periodically inspect the bearings, bushings and other components for signs of excessive
wear.
3-5 Maintenance Log
Date
Maintenance Performed
Initials