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Power hop is a condition where the tractor exhibits severe bounce and/or jump at field working speeds under 16 km/h (10 mph). Power hop is associated with tractors pulling towed implements at medium to high draft loads in loose, dry soil on top of a firm base and/or when climbing hills. As a result, the tractor cannot maintain pull due to loss of traction, rough ride, or both.
Adjust inflation pressures
only
after following the performance guidelines (recommended weight split, correct ballast, and correct inflation pressures):
1.
A) Increase
FRONT
tire pressure by 41-55 kPa (0.4-0.6 bar) (6-8 psi) in 2 psi increments over the rated pressure for the axle load. Follow steps 2 and 3 below.
B) If power hop remains a problem, reduce front tire pressure to the rated pressure. Then raise the
REAR
tire inflation pressure by 41-55 kPa (0.4-0.6 bar) (6-8 psi) in 2 psi increments above rated pressure for the axle load. Follow steps 2, 3, and 4 below.
NOTE:
Raising the front or rear inflation pressure depends on weight splits, operating conditions (steep slopes) or travel speeds. On steep slopes and operating speeds above 8.8 km/h (5.5 mph) raising the rear tire pressure is recommended.
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Tires on one of the two axles must remain at rated pressure.
Ballast tractor so no more than 55 percent of the total tractor weight is on the front, for best power hop control.
2.
Remove any liquid ballast and replace with cast weight equivalent, if power hop remains a problem.
3.
Liquid ballast has a stiffening effect that causes a rough ride. If liquid ballast is used in the rear tires,
all tires on the axle must be filled to the same level
which should not exceed 40 percent fill.
IMPORTANT:
Do not use liquid ballast in scraper REAR tires, unless used with dolly-wheels.
4.
If power hop remains a problem, see your John Deere Dealer.
NOTE:
Recommendations to control power hop for tractors used in tillage application where front weight split desired is 55%.
For scraper use without dolly wheel, tractor will be setup between 65-75% front weight split.
Tire pressure adjustments should take into account tractor load as well as scraper added drawbar load.
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