In some previous posts, it was mentioned that when replacing an 840 motor with an 860 on Dual belt drive tables, that one should replace the stator only to keep the shims from the 840. The only shims I see on the old motor are between the bearing brackets and the housing. What is the disadvantage of replacing the entire assembly? After all, the newer models did not include them at all and seem to have been designed that way. I recently replaced an entire motor assembly including pulley and speed adjusting mechanism from a 1246 to a 510. The 510 seems to be running better than ever. What would I gain with the stator only replacement?

Fred, Seth, Bohhey, Any ideas?

Hi Fernando:

Sorry for being late in a reply. This answer will not be very technical, but...

My feeling is this: Dual's engineers put those shims in there for a reason - I don't know what it was. I can only surmise that after they designed the motor, thy found that it operated better with the shims. Remember that the 840 was the 1st one of this design. The 860 also has mounting bosses on the top and bottom bearing carriers - won't work with the shims. The other reason I like keeping the old armature is that you know that the height of the pulley is correct. You also don't need to change out the motor case.

This repair has always worked for me, and is relatively quick. BUT, you need to visually check the armature clearances before you tighten the mounting bolts down.

I have never tried to just swap the motors.

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