Blade Sharpening
NOTICE
■When sharpening blades, grind the same amount on each blade to maintain balance. Replace blades in pairs. Unbalanced blades will cause excessive vibration, which can damage gearbox bearings. Vibration may also cause struc- tural cracks to cutter.
1.Sharpen both blades at the same time to maintain balance. Follow original sharpening pattern.
2.Do not sharpen blade to a razor
3.Do not sharpen back side of blade.
Figure 6. Blade Sharpening
SLIP CLUTCH ADJUSTMENT (Figure 7)
The slip clutch is designed to slip so that the gearbox and driveline are protected if the cutter strikes an obstruction.
A new slip clutch or one that has been in storage over the winter may seize. Before operating the cutter, make sure it will slip by performing the following operation:
1.Turn off tractor engine and remove key.
2.Remove driveline from tractor PTO.
3.Loosen six 10 mm cap screws (6) to remove all tension from Belleville spring plate (5).
4.Hold clutch hub (3) solid and turn shaft to make sure clutch slips.
5.If clutch does not slip freely, disassemble and clean the thrust plate faces (4), flange yoke (1), and clutch hub (3).
6.Reassemble clutch.
7.Tighten Belleville spring plate (5) until it is against the thrust plate (4) of the clutch, and then back off each of the six nuts by 2 full revolutions. The gap between Belleville spring plate and thrust plate should be 1/8" as shown in Figure 7.
8.If a clutch continues to slip when the spring is compressed to 1/8" gap, check friction discs (2) for excessive wear. Discs are 1/8" when new. Replace discs after 1/16" wear. Minimum disc thickness is 1/16".
1.Flange yoke
2.Friction disc
3.Hub
4.Thrust plate
5.Belleville spring plate
6.10 mm x 1.5P x 50 mm Cap screw
7.10 mm x 1.5P Hex nut
8.12 mm x 1.5P x 65 mm Cap screw
9.12 mm x 1.5P Hex nut
Figure 7. Slip Clutch Assembly
22 Owner Service
(Rev. 9/4/2009) MAN0763 (10/10/2008)