To remove and replace the X-Drive Gears you will need the following tools:  

1. #2 Phillips screwdriver  
2. 10mm Socket or Nut driver   

Removing the X-Drive Gears  

1. Remove the bottom cover. Unplug the machine from the power supply and carefully lay the machine on its back. Remove the two rubber feet and 6 screws securing the bottom cover onto the base.  Return the machine to the upright position. Be careful to not pinch any wires  that can drop out of the base as you return the machine to upright.  
2. Remove the right side panel assembly: Remove all four side panel fasteners. Using the 10mm socket remove the two hex head bolts (and washers) from the top of the assembly. Remove the two Phillips head screws from the base of the side  panel with the screwdriver. Lift off the side panel.  
3. Remove the black plastic cover over the drive gears. This cover simply pops off when it is squeezed and pulled up and out. You will then have access to the gears.

4. Remove the screws holding the X-Drive DC motor pack. Use the #2 Phillips head screw-driver to remove the two screws (and lock washers) holding the X-Drive DC motor pack as shown in Figure 2. Once these screws are removed the motor pack will drop down into the base.  

Reassembling the X-Drive Gears  

1. Clean the X-drive enclosure. Using compressed air, blow out any debris from the  X-Drive enclosure. It is critical that there be no dust or debris that could ever work its way into the X-Drive gears.  
2. Replace the single X-drive gear train plate assembly. Slide the X-drive gear plate assembly into position from the right of the leadscrew. The inner gear on the Stage 2 gear assembly will mesh with the two metal gears on the ends of the belt  tray drive rollers. Turn the center gear slightly by hand to make sure that it is centered and meshing properly. Replace the four screws (with lock washers) and firmly hand-tighten the four screws.  Do not mechanically over-tighten because the plastic base can strip out. Once fully tightened, turn the large Stage 1 gear one full revolution by hand to make sure that there is no excessive drag on the system at any point around its circumference.  
3. Replace the X-Drive DC motor pack. Slide the machine to the side of your workbench so that you can reach up underneath and insert the X-Drive motor pinion into the hole in the X-drive gear plate. Next, position the pack so that the screw holes in the X-drive plate and the motor line up. Insert the screws with the lock washer and firmly hand-tighten the screws.  
4. Do a final test on the X-Drive gear train. Turn the Stage 1 gear by hand at least 6  revolutions in both directions to make sure that the gears run smoothly. If you have  tested each set as it is assembled it should run smoothly. Note: there is considerable load on the system so turning the gear by hand is somewhat difficult.  Look specifically for spots of increased load as you turn the gear. Place a small dab of grease (the size of a pencil erasure) on the teeth of the Stage 1 and Stage two  gears to reduce noise and wear.  
5.  Replace the black plastic cover over the drive gears: Insert the two hooked tabs on the bottom of the cover into the slots in the base and slide into place. The cover will snap in place if it is correctly located. 
6. Replace the right side panel assembly: Place the side panel assembly back onto the machine making sure that the bottom of the panel sits into the grooves and tabs located on the base casting. Insert the two bottom screws and tighten with a #2  Phillips screwdriver. Insert the top hex head bolts (with washers) and tighten with the 10mm socket.  
7. Replace the bottom cover: Carefully lay the machine on its back again. Replace the two rubber feet and 6 screws securing the bottom cover onto the base.