Buhler 2425 - Manual (Page 214)

SECTION 2 - OPERATION
2-156
BALLASTING
Basic Rules of Thumb for Ballasting
1. When using fluid, put equal amounts in each
tire on a given axle.
2. Ballast tractors to a minimum amount as a
starting point.
3. For light-duty application, weight distribution
front to rear is not as important as in heavier
draft applications.
4. At maximum operating weight, the correct
recommended weight distribution of 55/45
(front/rear) for drawbar applications and
65/35 (front/rear) for 3-point hitch
applications is essential.
5. Set tire inflation pressures based on weight
carried by each wheel. Do not go below 55
kPa (8 PSI) on radials or 83 kPa (12 PSI) on
bias tires.
Application and Ballasting
Buhler Versatile 4WD tractors work in many
different conditions and operations. Therefore it
is up to the operator to ensure that the tractor is
performing at its peak in its specific operations.
Unlike crawler-type tractors, these tractors are
designed to operate at speeds of 7.2 KPH (4.5
MPH) and higher. At these speeds, they are
more productive and are less likely to have
mechanical breakdowns.
Many factors determine a tractor’s productivity.
Factors such as the size of the load, tractor
wheel slip, tire rolling resistance, tractor
operating weight and tractor weight distribution
all must be taken into consideration when
operating an Buhler Versatile 4WD tractor.
Loads Matched to the Tractor
Do not operate the tractor with heavy implement
loads that need the use of gears in the lower
ranges. The tractor is made for continued field
operation at the rated HP and ground speed of
7.2 KPH (4.5 MPH) and faster with a load that is
correctly matched to the tractor. If you operate
the tractor with too much ballast and pull too
heavy a load for a long period of time in the low
gears, you will cause damage to the drivetrain
and decrease tire life.
The best traction occurs when wheel slip is
between 8% and 15% for drawbar work and
13% to 15% for 3-point hitch work. The extra 5%
is to compensate for additional tire distortion
caused by weight transfer from the hitch.
If possible, remove ballast when not needed for
lighter loads.
Pull lighter loads at a faster speed to do more
work and increase efficiency. Do not overweight
the tractor to pull very heavy loads.
If the implement cannot be pulled at the needed
depth at 7.2 KPH (4.5 MPH) or greater, the
implement is over matched for your tractor.
The best guide to follow in ballasting is to not
have the full load wheel slippage fall below 12%.
This amount of slippage is your best protection
against overloading.
Wheel Slip
Wheel slippage is a vital consideration in any
farming operation. Too much slippage
represents lost time and wasted production. Too
much wheel slippage is a major cause of wheel
traffic-induced soil compaction. Too little can
result in reduced reliability of the drivetrain.
Strive for 8% to 15% wheel slippage on a 4WD.
Wheel slip is defined as the amount of tire
rotation “wasted” during one complete rotation
of a tire. Wheel slip is not a deterrent to tractor
operation. It is a necessary function of the tires
and helps prevent damage to the tractor
drivetrain due to tractor overload.
Every time a tractor wheel makes a revolution,
the wheel covers a certain distance. On a very
firm dry surface (i.e., asphalt), the distance
covered in one tire revolution will be very close
to the actual circumference of the tire. On a very
loose surface (i.e., sand), the distance covered
in one tire revolution will be significantly less
than the actual circumference of the tire. This
“wasted” distance is referred to as wheel slip.