Multi-Tool: Motor Spins but Shaft Doesn't
When the motor spins but the shaft doesn't in your multi-tool, in most cases this is an issue with the coupler. Read on for instructions on how you can replace a broken coupler yourself. If you need instructions specifically for your model, please refer to your owner's manual.
Couplers
Some multi tools have a coupler that connects the armature to the drive shaft. If the coupler breaks, the motor will run, but the output shaft will remain stationary. To replace a broken coupler, remove the collet nut and front cap from the tool. Remove the brush caps and brushes. Separate the two halves of the housing. Lift up the drive shaft and remove the broken coupler. Then, slip the new one onto the armature shaft and drive shaft. Place the drive shaft back in the housing and then reassemble the housing. Reinstall the front cap, collet nut, brushes and brush caps. ... Read more