Changing Friction Wheel Rubber - MTD 640 Operator's Manual

Support
Bracket
Rear Auger
Belt
Front Auger
Auger
Pulley
Pulley
Figure 16
Drive Belt
• Follow steps 1 through 4 of previous instructions.
• Pull idler pulley up, and lift belt off engine pulley
and friction wheel disc. See Figure 15.
• Back out the stop bolt until the support bracket
rests on the auger pulley. See Figure 17.
• Slip belt between friction wheel and friction wheel
disc. Remove and replace belt. Reassemble
following the instructions in reverse order.
NOTE: The support bracket must rest on the stop bolt
after the new belt has been assembled. See Figure
25.
Friction
Wheel
Disc
Stop
Bolt
Support Bracket
Figure 17

Changing Friction Wheel Rubber

The rubber on the friction wheel is subject to wear
and should be checked after 25 hours of operation,
and periodically thereafter. Replace the friction wheel
rubber if any signs of wear or cracking are found.
Friction
Wheel
Frame
Support
Bracket
Idler
Auger
Spring
Spring
Housing
Friction Wheel
Drive Belt
• Drain the gasoline from the snow thrower, or
place a piece of plastic under the gas cap.
• Tip the snow thrower up and forward, so that it
rests on the housing. See Figure 18.
Chute
Auger
• Remove six self-tapping screws from the frame
cover underneath the snow thrower.
• Remove the klick pins which secure the wheels,
and remove the wheels from the axle.
• Using a wrench to hold the shaft, loosen, but do
not completely remove, the hex nut and bell
washer on left end of gear shaft. See Figure 18.
• Lightly tap the hex nut to dislodge the ball bearing
from the right side of frame. Remove the hex nut
and bell washer from left end of shaft.
• Slide the gear shaft to the right and slide the
friction wheel assembly from the shaft.
• Remove the six screws from the friction wheel
assembly (three from each side). Remove the
friction wheel rubber from between the friction
wheel plate. See Figure 19.
Screws
Friction Wheel
Rubber
• Reassemble new friction wheel rubber to the
friction wheel assembly, tightening the six screws
in rotation and with equal force.
• Position the friction wheel assembly up onto the
pin of the shift rod assembly, and slide the shaft
through the assembly. Reassemble the wheels
and the frame cover.
13
Hex Nut and
Bell Washer
Note: The unit is
shown standing on
auger housing
Figure 18
Friction Wheel
Plates
Bearing
Hub
Figure 19