A component tractor consists of a stock tractor engine (or several, depending on the class), a 3 or 4 speed transmission (to give a range of ratios for various tracks and conditions), a right angle drive to get the power from the engine to the wheels, and a further gear reduction between that and the wheels, called a planetary gear.  All this is mounted solidly in a tubular chassis to ensure rigidity and strength, with enough flex to allow the tires to stay down in the dirt where they belong.  (More on this later.)  Add some massive brakes at the rear wheels (for steering) and a roll cage to protect the driver, some sheet metal to match the engine and cover it all for safety, and you have a component race tractor.

As the old saying goes, “Speed costs money, how fast do you want to go?”  The same applies to the sport of tractor pulling, only changed to “How far do you want to pull?”  Advances in technology and a natural progression of the sport have caused the creation of new classes (and revisions of old ones) for various reasons.  Every form of racing has an entry level class (usually the cheapest), an intermediate level, or several, depending on the sport, and a professional, sponsored, all out, balls to the wall, do what it takes to win within the rules class.  Component chassis rules have allowed the costs for whatever class you choose to run to be basically the same, with the exception of the engine costs (one 504 alcohol vs. multiple blown hemis).

Lets compare components to the typical cast iron tractor.


Cast Type
Standard base price plus options - all makes and model tractor engines can be used (within cubic inch limits), and sheet metal to match

Can be very expensive to lighten castings to get into certain weight classes, then may or may not have enough left over to hang on the front
Limited  to certain types of engine/rearend/sheetmetal cominations due to strength, parts availability, size limitations, etc.
Gear ratios of your choice - easily changed later
Gear ratio changes can be costly - bull gears have to be lightened which compromises strength
Whole component chassis with rear housing, front axle, roll cage and weight racks weigh less than average stock rearend  (700 lbs)  
Weight class limitations due to massive amounts of cast iron, large expensive to maintain gear trains, heavy housings
               No cast iron

Ever heard of a component breaking in half??
Safety factor involved in lightening cast iron - also gets brittle with age
Prone to crack or shatter
Requires tie bars between engine and transmission
Run the same tractor in more than one class
Double the checks!
Class specific regulations
Change engine/ sheetmetal by changing motor mounts - all engines mount 60 inches from center of rear axle

Try this on a stock tractor!
Parts in stock and readily available
Limited supply of new and used parts

Components finish out in the 5000 - 5500 lb range with driver!  

Standard weight racks available to add as many as 66  ninety lb I-H style weights
(16 on the front, 24 on the belly, 18 on the rear, and 8 behind the front tire)

How many do you have on the front??

A big advantage of the component chassis is its ability to flex.  Why is this important?  In a nutshell, an engine develops torque.  In a tractor, the engine torques clockwise (from a driver's perspective) and the driveshaft is attempting to rotate the rear axle housing counterclockwise.  The reaction to this torque, acting at the engine and transmission mounts, is attempting to rotate the rest of the tractor clockwise.  In a car, this reaction torque eventually finds its way to the front and rear suspensions.  It is distributed, front to rear, in proportion to the relative roll stiffness, or flex, of the chassis.  Since a tractor has no suspension, chassis flex plays a major role in helping cancel driveshaft torque.  

Where does this torque go in a rigid cast iron tractor or rigid component for that matter?  Simply put, it tries to lift the right rear wheel.

Latest Design IH Component Chassis

Typical Roll Cage