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Tractor weight and ballasting requirements vary depending on tractor equipment, tire inflation, and operating conditions. |
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Follow these instructions to determine ballasting requirements |
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| Step 1 |
Determine recommended total working weight and weight split for application ballast. |
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Total tractor weight requirement is found by multiplying the tractor PTO horsepower times the appropriate kilogram (pound) per horsepower. Kilograms (pounds) per horsepower requirements vary according to soil and load operating conditions. |
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Soil Type: |
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kg (lb)/PTO-hp |
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Light |
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54 kg (120 lb) |
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Medium |
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59 kg (130 lb) |
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Heavy |
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66 kg (145 lb) |
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Maximum total ballast must never exceed 66 kg (145 lb) per PTO-hp. |
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The total tractor weight necessary to maintain the recommended wheel slip range is influenced by soil type and travel speed. The ballast levels are based upon the following speeds: km/h (mph). |
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Soil Type |
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Travel Speed |
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Light |
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8.7 km/h (5.4 mph |
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Medium |
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7.7 km/h (4.8 mph) |
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Heavy |
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7.2 km/h (4.5 mph) |
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If different travel speeds are to be utilized, more or less weight will be needed. Higher speeds will not require as much weight. |
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In most cases, 59 kg (130 lb)/PTO horsepower will be enough weight to pull heavy loads. Example: |
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PTO hp 170 x 59 kg (130 lb) = 10,024 kg (22,100 lb) |
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10,024 kg (22,100 lb) is the total tractor working weight that would be needed at 59 kg (130 lb)/PTO horsepower. |
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Next, determine how much of the 10,024 kg (22,100 lb) weight needs to go on the front and how much on the rear of the tractor. Factory recommended weight splits are: |
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Front Axle |
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Towed |
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Semi-Integral |
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Integral |
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2WD (Front/Rear) |
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25/75 |
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30/70 |
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35/65 |
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MFWD/TLS (Front and Rear) |
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35/65 |
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35/65 |
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35/65 * |
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* Front weight requirements are determined by the weight of the hitch-mounted implement. Enough front weight needs to be added to maintain steering control. (See USING IMPLEMENT CODES in this section.) |
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In this example, the MFWD tractor will be pulling a towed implement. The recommended 35% of the total weight should be on the front and 65% should be on the rear of the tractor. |
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Total Front Weight: |
10,024 kg (22,100 lb) x 0.35 = 3509 kg (7735 lb) |
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Total Rear Weight: |
10,024 kg (22,100 lb) x 0.65 = 6516 kg (14,365 lb) |
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To determine how much weight needs to be added to the front and rear, go to Steps 2 and 3. |
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NOTE: Additional ballast may be required due to loss of tractor stability. |
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| Step 2 |
Determine current tractor weight by using the "UNBALLASTED TRACTOR WEIGHT CHARTS" or by using a scale. Find the chart with the correct tractor model and tire size. |
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The tractor in the example has MFWD and is equipped with 480/80R46 dual tires and has no front weights. The weight guide lists: |
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| Step 3 |
Subtract current tractor weight (determined in Step 2) from the recommended total weight and weight split (determined in Step 1) and add ballast as required. |
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Front Ballast: |
3509 kg (7735 lb) - 3074 kg (6777 lb) = 435 kg (958 lb) |
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Rear Ballast: |
6516 kg (14,365 lb) - 6141 kg (13,539 lb) = 375 kg (826 lb) |
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| IMPORTANT: |
There is a weight transfer effect when adding front weights. This weight transfer effect is 143 to 147% depending on configuration. For every 45 kg (100 lb) weight added to front axle, approximately 67 kg (147 lb) is added to the front axle and approximately 21 kg (47 lb) is reduced from the rear axle. (See INSTALLING QUIK-TATCH WEIGHTS in this section.) Rear weight is added directly to the axle with no transfer effect. |
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| Step 4 |
Adjust tire inflation pressures for optimum performance. (See TIRE INFLATION PRESSURE GUIDELINES in the Wheels, Tires and Treads section.) To get optimum performance from the tractor, inflation pressures must be correctly adjusted to gain maximum traction and minimum soil compaction. Ground pressure "soil compaction" is equal to 6.89-13.79 kPa (0.069-0.138 bar) (1-2 psi) higher than tire inflation pressure. |
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| Step 5 |
The final determining factor of correct ballast is a wheel slip measurement in the field. Under normal conditions wheel slip should be: |
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Tractor |
Percent |
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2WD |
10-15 |
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MFWD |
8-12 |
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Radar is needed to calculate average wheel slip. When tractor is equipped with radar, wheel slip will be displayed in the vehicle monitor window. Checking wheel slip manually is possible but will only show slip in one area of the field. (See MEASURING WHEEL SLIP-MANUALLY in this section.) Field conditions vary from one area to another. Maintain the correct average wheel slip to maintain optimum traction performance. |
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| Step 6 |
Add more weight to drive wheels if slip is excessive. If there is less then minimum slip, weight should be removed. |
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NOTE: To extend drivetrain life, never add ballast that results in continuous full power loads below 6.6 km/h (4.1 mph). |