New Holland 499 Operator's Manual page 41

To increase the reel speed, remove the cap screw
and clip at 1, and rotate the outer sheave half, 2, in
a clockwise direction.
For a lower range of speeds, remove the outer
sheave half and turn the low side in toward the belt.
NOTE: Do not turn the sheave half out past flush with
the hub.
IMPORTANT: When installing the cap screw and clip
at 1, be certain to reuse the two lock washers under
the clip. These serve as spacers to allow the clip to
float.
After adjusting reel speed, check the reel drive belt
tension as detailed in "Reel Drive Belt."
REEL DRIVE BELT
WARNING
Disengage the PTO, turn off the tractor engine
and remove the key. Wait for all movement to
stop before leaving the operator's position.
Never adjust, lubricate, clean or unplug machine
with the engine running. Failure to comply could
result in death or serious injury.
The reel drive belt, 1, must be tensioned to slip if the
reel hits a foreign object in the field or if the reel is
overloaded.
Adjust the eyebolt for a spring length of 304 mm(12")
between spring hooks as shown at 2.
NOTE: Belt tension must be adjusted after the reel
speed or position is changed.
Depending on the location of the reel or as the belt
stretches, it may be necessary to move stationary
idler, 1, so idler arm, 2, is perpendicular to the spring.
The arm should clear stop, 3, by a minimum of 13 mm
(1/2"). If clearance is less than 13 mm (1/2"), readjust
idler, 1, as required. Readjust the idler arm spring to
304 mm (12") hook-to-hook.
SECTION 2 - OPERATION
10004574
1
10004574
10004574
2-13
2
2
3
2
1
14
15
1
16