Change the skid plate on Husqvarna Automower 320, 330X, 420, 430X, 440 and 450X
Here is a step by step guide of how to disassemble and replace the skid plate on the Husqvarna Automower 320, 330X, 420, 430X, 440 and 450X.
A cracked or damaged skid plate causes an imbalance in the cutting system, resulting in missing blades or noise from the robotic lawnmower.

Changing the skid plate is a simple process and doesn't require any special tools. See below for step by step instructions.
At the bottom of the page there is a list of the spare parts needed for the job.

Tools used: Torx screwdriver T20.

Step 1: Turn your Automower over. Unscrew the three screws.	Step 2: Lift off the skid plate and its cover.
Step 3: Put in the new skid plate. There are "spikes" in the bearing holder that it should be placed on.	Step 4: Screw in the new skid plate with the three screws.

Make sure that the entire cutting system spins freely and that the skid plate does not catch on the screw heads of the blades.