Troy-Bilt 1900678 - Manual (Page 24)

MOWER MAINTENANCE
ADJUSTING W HEEL DRIVE TRACTION
(Self-Propelled Models Only)
On self-propelled mowers, there are two friction
drive rollers located in front of the rear wheels. See
Photo 5-1 or 5-2. These rollers propel the mower for­
ward by pressing against the tires.
When the wheel drive lever is in the upright,
NEUTRAL position, the rollers on 22" mowers should
be approximately 3/16" away from the crown (highest
point) of the tires. On 24" mowers, the clearance should
be approximately 1 /8". These two settings should pro­
vide adequate tire deflection (3/8" and 7/16" respec­
tively) for most mowing conditions. However, if extra
traction is ever needed, the clearance between the
rollers and the tires can be adjusted to a MINIMUM of
1/16", which will result in a tire deflection of
1 / 2 ".
NOTE: Use the minimum amount of tire deflection that
will ensure adequate traction for the job at hand. Doing
so will result in less wear on the tires and the rollers.
Follow the simple steps on this page to adjust the
wheel drive rollers.
Photo 5-1: Clearance should be 3/16" for 22" mowers.
B CAUTION: To avoic persona! injury, stop tne
engine, disconnect the spark plug wire, keep
the v/ire away from the spark plug, and allow the
engine and muffler :o cool before making reoairs
or adjustments.
A, Make certain that each tire is equally inflated to
between 25-30 psi. Tire pressure is very important in
maintaining correct friction roller tension.
B. Firmly grasp the threaded end of the lower drive
control rod with one hand (to prevent it from springing
forward when you release the clevis pin) and remove
the spring clip and clevis pin that secures the traction
adjustment block to the mounting bracket. See Photo
5-3.
Photo 5-3: Hold control rod when removing clevis pin.
C. Rotate the adjustment block in a clockwise direc­
tion to reduce the clearance between the rollers and
the wheels, or counterclockwise to increase the
distance. See Photo 5-4. A few turns in either direction
is usually all that will be needed for most adjustments.
Photo 5-2: Clearance should be 1 /8" for 24" mowers.
Photo 5-4: Thread adjustment block clockwise to
reduce roller clearance, or counterclockwise to in­
crease clearance.
D. Align the hole in the top of the adjustment block
with the hole in the mounting bracket and replace the
clevis pin and spring clip.
E. Engage and disengage the wheel drive lever
several times to verify that the correct clearance is ob­
tained. If not, repeat Steps B, C and D.
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