Change the cutting motor on Husqvarna Automower 420, 430X, 440 and 450X
Here is a step by step guide of how to disassemble and replace the cutting motor on the Husqvarna Automower. As shown on an Automower 420. The same principle applies to 320, 330X, 430X, 440 and 450X.
A faulty cutting motor can generate the error message "Cutting system blocked".

At the bottom of the page there is a list of the spare parts needed to do the job.

Tools we use: Torx screwdriver T20, Allen key size 5.

Step 1: Turn your Automower over and disconnect the power cable. First remove the rubber cap; then disassemble the charging connector.	Step 2: Detach the chassis. You do this by holding the lawnmower as shown in the picture and using your right hand to pull the chassis upwards. It's attached by two points on the back and two on the front.
Step 3: Unscrew all the screws around the chassis. 14 in total.	Step 4: Lift up the top of the chassis. Unplug the long white flat lead that goes to the motherboard according to the marking. Put the bottom part of the chassis to the side.
Step 5: Turn your Automower over. Loosen the three screws of the skid plate according to the markings.	Step 6: Lift off the skid plate and the cover. Unscrew the centre screw for the bearing holder according to the marking.
Step 7: Lift the bearing holder straight off and set aside. Now you can get to the screws for the blade disc. Unscrew the three marked screws to release the blade disc.	Step 8: Lift the blade disc off the shaft and unscrew the four marked screws to release the cutting motor.
Step 9: Turn the robot over and disconnect the wiring to the cutting motor from the motherboard as marked.	Step 10: Turn the robot over and remove the old cutting motor.
Step 11: Take out the new mower motor and screw it into its four screws according to the markings.	Step 12: Plug the new cutting motor into the motherboard.
Step 13: Replace the blade disc and screw in with the three screws according to the markings.	Step 14: Put the bearing holder back and screw in the centre screw. The "spikes" on the bearing holder must be facing upwards when the skid plate is attached to them.
Step 15: Put the skid plate and the lid back on and screw in the three marked screws. Make sure the cutting system can rotate freely without making any noise.	Step 16: Get out the upper part of the chassis and connect the white flat lead to the motherboard. Please note! Change the sealing strip in the under chassis at the same time to avoid damage caused by damp.
Step 17: Screw in all the screws around the chassis. 14 in total.	Step 18: Put the chassis on the robot by placing it on all four points simultaneously. Finally, connect the charging cable and press the rubber plug back into the lower part of the chassis.