Grosite 4S9-06N-8C01 Spindle Repair

The Grosite 4S9-06N-8C01 spindle is grease lubricated, belt driven, and capable of running up to 3,600 rpm.

CHALLENGE

This Grosite 4S9-06N-8C01 spindle arrived at Northland Tool and Electronics we noted that the spindle spun free, but had a deep growl to it when spun by hand.  The spindle did pass an electrical test, but there was a mixture of an oily black particulate throughout the spindle.  The grease in all the bearings was completely washed out by this contaminant and felt rough and scratchy.  We found a broken o-ring under the front cover that could have let to the contamination.  We then measured and inspected all the critical surfaces (bearing journals, housing, taper, etc.).  There was slightly high runout on the OD taper and the taper had rubout damage with very poor tool contact.  No other dimensional deviations were noted for the repair.

SOLUTION

The following actions were performed on this Grosite 4S9-06N-8C01 spindle:

• Clean, inspect overall dimensions
• Replace bearings, o-rings, and assembly screws
• Grind, chrome plate, and finish grind the OD taper

RESULT

After reassembly of all components, adjusting bearing preload, and undergoing break-in and testing procedures, this spindle passed our final quality inspection before being returned to our customer with a 1-year warranty.