Exmark 4500-540 Rev. B manual Wheel Hub-Slotted Nut Torque Specification, Thread Locking Adhesives

Maintenance

4.Thoroughly clean the area around each of the charge pump housings.

5.To “prime” charge pump, loosen two hex socket head capscrews (shown in Figure 14) 1 1/2 turns only. Make sure engine is not running. Lift the charge pump housing upward and wait for a steady flow of oil to flow out from under the housing. Retighten the capscrews. Do this for both pumps.

Note: Hydraulic reservoir can be pressurized up to 5 psi to speed this process.

6.If either drive wheel still does not rotate, stop and repeat steps 4 and 5 above for the respective pump. If wheels rotate slowly, the system may prime after additional running. Check oil level as stated in Check the Hydraulic Oil Level section.

7.Allow unit to run several minutes after the charge pumps are “primed” with drive system in the full speed position. Check oil level as stated in Check the Hydraulic Oil Level section.

8.Check hydro drive linkage adjustment as stated in Hydro Drive Linkage Adjustment section in Adjustments.

Wheel Hub-Slotted Nut Torque Specification

Service Interval: After the first 100 hours Every 500 hours thereafter

When tightening the slotted nut on the wheel motor tapered shaft:

1.Torque the slotted nut to 100 ft-lb (136 N-m).

2.Further tighten the nut until the next set of slots line up with the cross hole in the shaft.

3.Replace cotter pin.

Note: Do not use anti-seize compound on the wheel hub.

Inspect PTO Clutching Belt Tension

Service Interval: After the first 2 hours Check every 2 hours for the first 8 hours of operation.

Every 40 hours thereafter.

1.Stop engine and wait for all moving parts to stop.

2.Engage PTO lever.

3.Look through the round hole in the left rear corner of the engine deck to inspect blade clutching belt tension. Bolt on blade engagement linkage bellcrank and indicator arm should align within 1/16 inch (1.6 mm) (see Figure 15). Refer to PTO Engagement Linkage for adjustment.

Figure 15

1.	Engine deck	3.	Align bolt to indicator
			within 1/16 inch (1.6
			mm)
2.	Indicator	4.	Turnbuckle

Thread Locking Adhesives

Thread locking adhesives such as “Loctite 242” or “Fel-Pro, Pro-Lock Nut Type” are used on the following fasteners:

•Pump sheave setscrews.

•Square head setscrews on hydro pump control arms.

•OPC lever setscrews.

•Lower sheave retaining bolt on clutch arm.

•Shoulder bolts in ends of speed control crank.

•Sheave retaining bolt in end of engine crankshaft.

•Fuel tank bulkhead fitting threads

Adhesives such as “Loctite RC/609 or RC/680” or “Fel-Pro Pro-Lock Retaining I or Retaining II” are used on the following:

•OPC lever hubs and cross-shaft.

Note: Care must be used not to bond the bearing, next to each OPC hub, to the cross-shaft

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