Recommended step-by-step procedure Firestone dealers and service people should follow to reduce or eliminate power hop on mechanical front-wheel-drive tractors.

The overall goal in reducing or eliminating power hop is to reduce the tractive effort of the front tires by:

• Stiffening the front tires by either increasing tire inflation or adding liquid ballast.
  
• Softening the rear tires by reducing tire inflation and removing liquid ballast.

Generally, to successfully control power hop, a mechanical front-wheel- drive tractor must be equipped with duals or triples on the rear axle.

Step 1: Check Implement Adjustment and Drawbar Position. Check to be sure that the implement hitch and tractor drawbar are properly adjusted. This information can be found in the individual operating manuals for the implement and tractor. Once the implement hitch and tractor drawbar are properly adjusted, proceed to Step 2.

Step 2: Check for Proper Weight Distribution. If you find that the tractor is not properly ballasted, adjust it according to the manufacturer’s ballasting recommendations for weight split, total working weight and wheel slip.

Generally, the weight split will be 35 percent front, 65 percent rear. Once the tractor is properly ballasted, proceed to Step 3.

Step 3: Adjust Front and Rear Tire Inflation Pressures. Adjust the inflation pressures in both the front AND rear tires as follows. (NOTE: BOTH FRONTS AND REARS NEED TO BE DRY!)

Fronts: 2-star or 8-ply tires – INCREASE each tire to 30 psi.

3-star or 10-ply tires – INCREASE each tire to 36 psi. Rears: Set each tire to the minimum pressure required to carry the axle load.

Stop & Test. Check the tractor for hop and performance. If the power hop has been eliminated, no further adjustments are necessary. If the power hop is still present and the front tires are dry, proceed to Step 4.

Step 4: Add Liquid Ballast to Front Tires Only. Using the appropriate equipment, install liquid ballast in ALL the front tires to 75 percent (normal) fill. The tire is 75 percent filled when the valve stem is in the 12 o’clock position. (NOTE: KEEP REAR TIRES DRY!)

Stop & Test. Check the tractor for hop and performance. If the power hop has been eliminated, no further adjustments are necessary. If the power hop is still present, proceed to Step 5.

Step 5: Increase Liquid Ballast in Front Tires Only. Using the appropriate equipment, increase the liquid ballast in EACH front tire to 90 percent fill. After increasing the liquid ballast, keep the inflation pressures in the front tires as follows:

• 2-star or 8-ply tires – KEEP each tire at 30 psi.
  
• 3-star or 10-ply tires – KEEP each tire at 36 psi.

Keep the weight split at 35 percent front/65 percent rear by adding cast weights to the rear. Do not change the pressures in the rear tires, and keep the rear tires dry.

Stop & Test. Check the tractor again for hop and performance.

If the power hop is still present, contact Firestone Field Engineering at 1-800-847-3364.

WHEN YOU’RE DONE IN THE FIELD, MAKE SURE TO ADJUST THE FRONTS BACK TO NORMAL PSI PRESSURE.