MTD 500 series Shop Manual page 66

Medium Frame 2 & 3 Stage Snow Throwers
12. Inside of each Planetary Gear Set is a series of
Planetary Gears that rotate around a Sun Gear and
rotate inside of the Ring Gear. See Figure 6.25.
NOTE: The groves are grease grooves.
13. Although the Planetary Gears rarely have any ser-
vice issues, a good working knowledge is important.
• The Hex Drive Shaft transfers torque from the
Friction Wheel to the Sun Gear on each end of
the Hex Drive Shaft.
• The Sun Gear drives the Planetary Gears.
• When unlatched, trigger squeezed, the Ring
Gear is allowed to spin freely.
• When the Ring Gear spins freely it will not drive
the Planetary Gear Carrier.
• When the trigger is released and the Ring Gear
is latched, preventing it from rotating. The
Planet Gears drive the carrier in the opposite
direction of the Sun Gear, but at greater speed.
• The Drive Gear attached to the carrier transfers
power to the Axle Half.
NOTE: Inspect the component, replace/repair as
needed.
14. Slide the Friction Wheel Assembly onto the Hex
Drive Shaft so that the hole for the pin, on the shifter
arm, is away from the E-ring on the shaft.
15. Install the thin washer and Planetary Carrier.
16. Install the Sun and Planetary Gears. See Figure
6.26.
17. Apply a generous coating of Arctic Grease (737-
0318-CRTG) to the inside of the Ring Gear and on
the gears.
18. Install the Ring Gear, E-ring, washers and bearing.
See Figure 6.27.
19. Repeat steps 15 through 18 on the opposite side.
20. Install the Hex Drive Shaft assembly by following
steps 1 through 5 in reverse order.
21. Coat the hex section of the Hex Drive Shaft with a
generous coating an anti-seize compound.
22. Test drive the snow thrower in a safe area before
returning it to service.
62
Planetary Gears
Ring Gear
Figure 6.25
Sun gear
Figure 6.26
Ring gear
Figure 6.27
Planetary Gear Carrier