3-100
Section 3 - Operation
Ballasting
Tractor Weight Distribution
Although Buhler Versatile 4WD tractors are manufactured with an approximate weight distribution of 65% - 67% over the front axle and 33% - 35% over the rear axle, the intent of the design is to have the tractor operating in the field with an ideal 50/50 dynamic weight distribution..
The benefits of operating a tractor in the field under the ideal 50/50 dynamic weight distribution are:
1.The work is divided equally between the axles, allowing a more even distribution of work and load..
2.Compaction is lessened since the axles are the lightest force possible on the soil.. If a 13,636 kg (30,000 lbs) tractor has a 50/50 split, each axle exerts a force of 6,818 kg (15,000 lbs).. A 60/40 split would create an 8,182 kg (18,000 lbs) force under the heavier axle, increasing the compaction by 1364 kg (3000 lbs)..
3.Maximum traction, with the least rolling resistance, is gained by distributing the load equally between both axles..
4.With the total tractor weight equally divided (under load) on all four wheels, you increase reliability by spreading the torque output of the tractor equally to all four wheels.. The greatest torque always goes to the wheels with the most weight..
NOTE: The tractor has a maximum axle weight capacity:
Model | Maximum continuous weight per axle |
435 | 27,000 lbs.. |
485 | 30..000 lbs.. |
535 | 32,000 lbs.. |
(Based on 100 lbs/hp x 60%)
Calculation of Ballast
The following information is provided as a guide for proper ballasting:
Shipping Weight and Fore/Aft Ratio
The shipping weight of the tractor will be approximate distributed at 65% - 67% on the front axle and 33% - 35% on the rear axle..
Do not assume that every tractor will come from the factory with this weight distribution.
Various options and wheel packages will significantly change the weight of the tractor.. Determine the shipping weight BEFORE any ballast is added to the tractor by weighing the tractor on a scale.. This is the most accurate method of determining actual tractor weight and ballasting the unit correctly.. Possible locations of a scale of adequate size to weigh the tractor would be a feed/fertilizer store, asphalt plant, gravel quarry, grain elevator, etc..
NOTE: There is an additional method of calculating the shipping weight of the tractor using calculated weight from theoretical value charts located in the Section 6 of this manual. Weighing the tractor on a scale is preferred.
When weighing the tractor, pull the front axle on the scale first.. Make sure the inside wheels of the dual or triple tires are fully on the scales and the outer tires are off of the ground.. Since most scales are less than 3 m (10") wide, driving the inner wheels up on wooden blocks will accomplish this.. Repeat this procedure for the rear axle.. Record the unballasted weight of each axle.. Add the weight recorded for each axle together to get a total tractor shipping weight.. Divide the individual axle weights by the total tractor shipping weight to get the front to rear weight distribution percentage..
