Generally the average working life of DECI can be over 3 years.
DECI offers one year warranty for Spindle Motors.
But in case,some of the common spindle performance issues could appears as below(because of many reasons):
Noisy bearings
Contaminated bearings
Increased vibration
Poor part finish
Failed seal
Shaft end play
Shaft seized
Excessive runout at Pilot ID & OD
Misalignment