Exmark 4500-689 Wheel Drive Belt Pulley Scrapers, Engine to Mower Deck Belt, Transmission Belt

Maintenance

Height Adjustment Table and notes in the Adjusting the Cutting Height section.

9.Install unused spacers between top of spindle and spindle nut.

10.Torque bolt to 75–80 ft-lb (102–109 N-m) (see Figure 12).

Wheel Drive Belt Pulley Scrapers

1.Stop engine and wait for all moving parts to stop. Engage parking brake. Remove key or spark plug wire(s).

2.Be sure mud and grass scraper, on each side, is adjusted properly and centered in the pulley grooves. The pointed part of the scraper should be centered and as deep in the pulley groove as possible without rubbing at any point.

			Engine to Mower Deck Belt
			1. Stop engine and wait for all moving parts to stop.
			Engage parking brake. Remove key or spark plug
			wire(s).
			2. Check the adjustment of the lower blade drive
			linkage located between the bellcrank on the
			engine deck and assist arm on the mower deck.
			Lengthen or shorten the linkage. When properly
			adjusted, there should be 1/16 inch to 1/8 inch
	Figure 12		(2–3 mm) of clearance between bell-crank and
			transmission output shaft when belt is engaged.
1. Spring disc washer	2.	Blade bolt torque to	Make sure the assist arm is against the rear assist
(cone towards bolt head)		75–80 ft-lb (102–109	arm stop on the deck (see Figure 13). Push the
		N-m)	lever down to the disengaged position. The assist
			arm should contact the front assist arm stop on
Transmission Belt			the deck. If it does not contact, readjust so that
			the bellcrank is closer to the transmission output
Adjustment			shaft.
			3. Belt must be tight enough to not slip during heavy
1. Stop engine and wait for all moving parts to stop.
			loads while cutting grass. Over-tensioning will
Engage parking brake. Remove key or spark plug			reduce belt and spindle bearing life. To adjust
wire(s).			belt tension, loosen the 5/16 inch whizlock nut
2. To tighten transmission belt, loosen the 3/8 inch			on turnbuckle and rotate the turnbuckle; rotate
nyloc nut on transmission belt idler pulley. Slide			turnbuckle toward rear of mower to tighten, and
bolt inward in slot and retighten nyloc nut.			toward front of mower to loosen belt tension (see
3. When properly adjusted, the belt should have 1/2			Figure 13). Leave a minimum of 5/16 inch (.79
			cm) of the eyebolt threads engaged on both ends
inch (1.3 cm) of deflection with three pounds
			of the turnbuckle.
of pressure on the belt midway between the
			For 48” Decks: If there is no adjustment left in
transmission and engine pulley.

the turnbuckle and the belt is still loose, the rear idler pulley can be repositioned in the front hole (See Figure 12). The belt guide located next to the pulley must also be repositioned in the front hole when the pulley is moved. The turnbuckle will need to be readjusted.

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