Rapid motor sheave/pulley removal (HVAC)

Written by: roboguru

Electricity and motors are dangerous. If you don't know how to be safe, then please don't do this. If you manage to maim, damage, kill or otherwise injure yourself. Don't blame me.

I had to replace 4 or 5 pulleys in fairly short order. I filmed each step on a different pulley. I apologize in advance if this upsets your OCD. Also, I tested the electrical system properly, with 2-hands before filming, During the film, I neglect to show testing each phase to ground. I needed two hands to do that, so wasn't able to film it.

What you need:
Safety Glasses!
Pulley puller
1/4" quick connect Impact Driver
1/4" quick connect to 1/2" socket conversion bit
5/8" socket
5/32" allen key
Digital Multimeter
Non-Contact Voltage stick
Various Hand-tools and bits.
Penetrating Oil/WD-40/Rust Buster etc.



  1. Lock out the machine you are working on. It takes 30 seconds, and prevents some dingus from energizing the machine when your fingers are somewhere dangerous. Do us both a favor, and be safe.
  2. Remove access panels.
  3. Don't trust disconnects. Always double check that the machine is not energized. I like to use my DMM to check that all phases of power are disconnected. Check L1-L2, L1-L3, L2-L3, and all phases to ground. If the motor you are working on is a single phase motor, watch out for capacitors that may be holding onto a charge.  
  4. Use an insulated non contact voltage stick to depress the motor contactor. This is a triple check, just in case your DMM has failed.
  5. Remove the belt and all set-screws
  6. Liberally apply penetrating oil to as many of the pulley/shaft areas as possible. Wait a few minutes, and do it again. 
  7. Set-up your pulley puller, attach your impact driver and pulse the trigger. It's easy to crack a sheave, so try to be gentle.

TIPS for ornery difficult to remove pulleys:
- If your sheave just won't budge, try removing the key from the shaft. Sometimes you can pull it out, sometimes you have to knock it out with a drift.
- If you have clearance behind the sheave, try using a brass rod and a hammer to smash the sheave backwards a touch. Then clean and polish the exposed shaft. Sometimes a burr or piece of junk prevents the sheave from coming off. 
- Sometimes access to the sheave is so terrible, it is easier and faster to remove the motor from the frame and work on a bench. 
- If you don't have enough room the get a puller in, try using a pickle fork.
- Don't stick your fingers anywhere you wouldn't stick your ... D'erm never mind.