Richard L. Parish | 11/17/2004 8:23:26 PM
You may be able to improve the performance of your compact utility tractor by ballasting the tractor properly. This will involve adding or removing weight.
Overall weight and weight distribution are important to traction, stability, safety and soil compaction. You generally want your tractor to be as light as possible to minimize soil compaction yet still be heavy enough to do the jobs required. More weight on the drive tires will increase the tractive force available for pulling. More weight on the front will reduce the tendency to overturn to the rear.
If you weigh the front end and then the rear end of your tractor at rest, the results will be quite different from the weight distribution when the tractor is pulling a load. When the tractor is pulling a load on the drawbar or 3-point hitch, weight is transferred from the front axle to the rear axle. This dynamic weight transfer is the phenomenon that can make the front of your tractor light and difficult to steer or even lift the front end off the ground. On a 2-wheel-drive tractor, this weight transfer is generally beneficial in that it improves traction, but it can be a safety concern if the front tires come off the ground.
Probably the first place to add weight to your tractor is the front end. Most compact tractors have some provision for adding weights on the front (Figure 1). In most cases, though, the weight bracket and weights are optional, not standard equipment. The weights used on the front of compact tractors are generally in the 50-pound range and are cast iron with a handle cast in. Most tractors can handle six to eight of these weights. They are often referred to as "suitcase weights" since you can lift them on and off by the handle.
Once in place, they should be locked down in some manner -- typically by a rod through the handle holes or other holes. Front-end weights help counterbalance the weight of rear implements when the implements are lifted and also contribute to traction when weight transfer under load effectively moves part of the weight to the rear axle. They can thus contribute to traction, stability and safety. They are relatively inexpensive.
Cast iron weights are also available to mount on the wheels. They are more common on rear wheels, but front wheel weights are sometimes available. Rear wheel weights add weight directly to the rear axle, and front wheel weights serve essentially the same purpose as front-end weights. Wheel weights are effective, but they are not as easy to add or remove as front-end weights. The tendency is to install them and forget them, thus the weights are in place even when not needed.
Fluid in Tires
An invisible way to add weight is to put fluid in your tires. This is most commonly done with rear tires but is also possible with front tires. Never fill a tire completely full; there must be room for air over the fluid. You should replace about 75 percent of the tire volume with water. The remaining air will provide the cushioning needed. A typical 12.4-24 tire will hold about 250 pounds of water, or 500 pounds for the two tires. In the South, plain water is often used in tires, but further north, a solution of calcium chloride is common. The calcium chloride solution provides two advantages: it weighs more per gallon, thus adding more weight, and it acts as an antifreeze. Obviously, you will not be able to install or remove fluid to match your current needs; fluid in the tires is generally left in place at all times. You can have a tire dealer install the water or do it yourself with an inexpensive hose-fitting device that allows you to bleed air as you add water. The following Web site provides information on the amount of water to add for different tire sizes:
A cast iron or concrete counterweight is sometimes added to the 3-point hitch when a tractor is used with a front-end loader. The weight will help counter the weight of the loader bucket and will help maintain traction on the rear tires. Hitching an implement on the 3-point hitch when using the loader accomplishes the same purpose.
Proper ballasting can make your tractor easier to steer, improve traction and make your tractor more stable; however, ballasting will increase soil compaction and stresses on axles and tires, so you should use only the amount of ballast needed for your job.