Maintenance

4.Verify that 12V is present at the clutch connector when the PTO switch is engaged.

5.Measure the gap between the rotor and armature. If the gap is greater than .04 inch (1 mm), proceed with the following steps:

A.Loosen both brake mounting bolts one-half to one full turn as shown below.

Note: Do Not remove the brake pole from the field shell/armature. The brake pole has worn to match the armature and needs to continue to match after the shim is removed to ensure proper brake torque.

Figure 40

1.Brake mounting bolt

B.Using needle nose pliers, or by hand, take hold of the tab and remove the shim (Do Not discard the shim until proper clutch function has been confirmed).

Figure 41

1.Shim

C.Using a pneumatic line, blow out any debris from under the brake pole and around the brake spacers.

D.Re-torque each bolt (M6 x 1) to 10 ft-lb (13 N-m) +/-0.5 ft-lb (0.7 N-m).

E.Using a 0.010 inch thick feeler gauge, verify that a gap is present between the rotor and armature face on both sides of the brake pole as shown. (Due to the way the rotor and armature faces wear (peaks and valleys) it is sometimes difficult to measure the true gap.)

Figure 42

1.Feeler gauge

Figure 43

1.Feeler gauge

If the gap is less than 0.010 inch, then reinstall the shim and reference the Troubleshooting section.

If the gap is sufficient, proceed to the safety check in step F.

F.Perform the following safety check:

a.Sit on the seat and start the engine.

b.Make sure the blades Do Not engage with the PTO switch “off ” and the clutch disengaged.

If the clutch does not disengage, reinstall the shim and reference the Troubleshooting section.

c.Engage and disengage the PTO switch ten consecutive times to ensure the clutch is functioning properly. If the clutch does not engage properly, reference the Troubleshooting section.

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Exmark 4500-507 manual Shim