Since the tractor was first developed people have
been devising new ways to make them more practical for different
applications. In the veggy producing parts of our lands, there was
a need to have a tractor that would ride over the tops of the crop
without damaging it. Thus, the "High Crop Models". Since
the whole tractor is to be lifted higher, is essence, the wheels
had to be lowered. This was accomplished, in the rear of the tractor,
by making a drop at the end of the axle housing, which meant, there
had to be some way to transfer the axle power to the now, new lower
location of the wheels. Some tractor companies done this with chains,
while others used a combination of chains and reduction gears. Keep
in mind that the wheel rotation still had to be in the same direction.
The use of a chain at the end of the rear end housing and the final
drive housing would still keep it in the same rotation as before.
A gear to gear final drive lowering device would reverse the rotation.
The John Deere "G" High Crop tractor, for example, used
the combination of both. The entire rear end housing was very different
then the regular tractor models. The high crop housing was made
so it was lower then the regular models. The differential would
drive the axles, via a chain on either side, which were positioned
lower because of the rear end housing being designed to lower the
axles. This changed the rotation of the drive axles, as opposed
to a regular tractor model, by eliminating the bull gears within
the rear end housing. This also increased the rotating speed of
the axle. The rotation and speed was then changed back, at the wheel,
by the geared final drive.
The drawbar was made lower by a system of support braces from the
final drives housings.
The front end was made lower by adding length to the Knee and Knuckle,
spindles. The regular knee was, 19-3/4 inches and the high crop
was 28-1/2 inches. The rest of the front axle assembly was the same
as all the rest of the wide front end models.
Most all high crop tractors were fixed rear wheel tread width,
due to having a final drive housing that didn't have any allowance
for sliding the wheel in or out. Some could adjust a little by reversing
the wheel on the hub, or by adding a spacer.
Some of the smaller tractors made the high crop world by simply
installing bigger wheels. The 40 series John Deere tractors, for
example, were one of these. By removing the regular size rear wheels
and installing wheels that are of larger diameter, and using longer
front knuckles, spindles, with larger diameter front wheels, it
raised it enough to be classafied as a high crop.
High crop tractor were for the level land only farming. Their special
design of highness was the failing feature that made them a death
contraption on the hills and farmers knew this. They were never
meant to be used for anything other than what they were designed
Even though they were mostly made for the American farm, some made
there way to other countries around the world.