Replacing MD roadbook drive belts
The o-rings on your MD roadbook may need replacing after a few years. You may notice that the drive belts are slipping. Here is a brief tutorial on changing the o-rings.
To tackle this project you will need:
- 2 O-rings (purchase in Spares)
- 1x large, #3200 (-136) VITON (50.47 mm ID x 2.62 mm thick)
- (pre-2011) 1x small, #3143 (-127) VITON (36.17 mm ID x 2.62 mm)
- (post-2011) 1x small, #3131 (-125) VITON (32.99 mm ID x 2.62 mm)
- (optional) 1x #2010 (-005) BUNA (2.57 mm ID x 1.78 mm) for right-hand knob
- small, flat-blade screwdriver
- 1.5mm allen key
Let's start with some nomenclature. There are 4 shafts in your MD roadbook. From the top down, they are:
- Upper guide roller
- Upper spool roller (with knob)
- Lower spool roller (with knob)
- Motor shaft
1) Remove the upper spool roller by holding the shaft with pliers and removing the knob from the end of the shaft. NOTE: This upper knob is left-hand (reverse) threaded.
2) Remove the lower spool roller by holding the shaft with pliers and removing the knob from the end of the shaft. NOTE: This lower knob is right-hand (normal) threaded.
3) Remove the bushing from the left-side of the motor shaft by prying it out from the inside with a small flat-blade screwdriver. The following photo shows the bushing removed.
4) Separate the motor shaft from the motor by loosening the small set screw.
5) Remove the motor shaft by sliding it to the left until it is free from the motor.
6) Replace old o-rings with new ones.
7) Reassemble in reverse order. Use a very small dab of medium-strength threadlocker on the knob threads.