2015 20 M.P.H.
Street Stock Diesel Truck Rules
Revised – Dec. 2017
Hitch: Tractor & Truck pullers hitch opening size requirements: 3 ¾ inch front to back and 3 inch side to side. Note: No loose clevis are to be used. (Revised – Dec. 2017)
This class is to be street vehicles that are allowed traction devices and limited by: no hanging weight, Reese hitch only at 20″ hitch height, and 20 MPH speed limit. Allow traction bars. Revised – Dec. 2017
Weight: 8500 1b
Ballast is permitted. Ballast may be added to the bed of truck. Ballast must be securely mounted in the bed. NO FRONT MOUNTED BALLAST OR WEIGHTS ALLOWED IN CAB, this will be enforced.
The Batteries must be securely mounted and in the factory location.
The body must be the OEM truck body including the full bed floor. The body must retain full sheet metal. Metal aftermarket hoods are permitted. No fiberglass hoods. The hood must be closed and securely latched while the truck is hooked to the sled. The complete OEM firewall and complete OEM floor pan is mandatory. A factory installed pickup bed or commercial aftermarket flatbed must be installed.
Four wheel hydraulic brakes are mandatory and must be functional.
The OEM chassis is mandatory, The engine must be in the OEM location for the body used. The vehicle must retain the full OEM chassis. Wheel tubs, back half conversions, tube chassis, etc, are prohibited.
Radiators must be in stock location and be of at least stock size.
Use of any compressed gases (nitrous or propane or any other) is prohibited.
All drivers must have a valid state driver’s license. Vehicle must have current registration and current license plates. And proof of insurance may be required.
An OEM transmission and transfer case are mandatory. They must have been an option on a one ton or smaller pickup.
Driver Restraint System:
The OEM restraint system is mandatory and must be worn.
The engine is limited to a stock appearing, OEM compression engine, available from the factory in a one ton or smaller truck.
All vehicles are recommended to be equipped to direct exhaust upward. The exhaust must exit rearward of the driver’s compartment. Stacks exiting through the hood or fender wells are prohibited.
The fuel must be pump #1, #2 diesel, or Soy/Biodiesel. Off road fuel is prohibited. Must be commercially available fuel.
Fuel Injection pump:
OEM FUEL SYSTEMS with the exception of a lift delivery pump and filters.
All engines turning more than 4500 RPM must be equipped with a harmonic balancer or dampener meeting SFI Spec 18.1.
The hitch must be a receiver style hitch, reinforcements are permitted. Reinforcements must not extend forward of the center line of the rear axle. Trick hitches are prohibited. Trick hitches will be determined by the Tech Officials. The hooking point must be the rear most point on the vehicle and must be rearward of the stock location of the tailgate. The hitch must be horizontal to the ground and stationary in all directions. Bumper may be notched or removed. The hitch’s height from the ground may not exceed 20 inches. The hooking point must have a minimum of 3 inch by 3 inch inside opening for the sled hook. The hooking point must be a minimum of 48 inches from the center of the rear axle to the hooking point. The hooking point will be where the hook touches metal. That is the hooking point.
Only OEM intercoolers are allowed.
A complete factory OEM interior, including dashboard, door panels, headliner, etc. is mandatory. Aftermarket seats are permitted, they must be fully upholstered. All factory controls, lights, windows, Signals, wipers, etc, must be retained and in working order. The uses of hand throttles are prohibited.
Non OEM rear-end housings are prohibited. The rear-end housings must have been for a one ton or smaller pickup Pick up. Rear axle bolts must be covered by a cap or shield.
The vehicle must retain the full, original OEM steering gear. The vehicle must retain the original OEM power assistance, if it was so equipped. Additional stabilizers are permitted. Non OEM power assist methods are prohibited.
Complete headlight and taillights assemblies (all) are mandatory and must be operative, and must be installed during competition. Complete OEM windshield and all other windows are mandatory. WIndows must be able to operate per factory specifications; they must open and close by electric or mechanical means.
Suspension – Front:
The factory suspension configuration must be retained. The upper mounting point for strut assemblies must be in factory location. Adjustable caster/camber pillow ball mounts are permitted. The lower control arm may be strengthened provided factory mounting points are maintained. The lower mounting point for the strut assembly may be modified for improved caster and camber. Strut tower braces, lower tie bars, sway bars, and limit straps are permitted. Traction bars and devices are permitted. Final decisions rest with the American Farm Pullers Association Tech Department.
Suspension – Rear:
An OEM style suspension is mandatory. Traction bars and devices are NOT permitted. The rear suspension must maintain a minimum compression shock travel of one inch. Compression stops may be adjustable. All rear suspension must use at least one working shock absorber per wheel. Air bag spring assist is prohibited.
The tires must be DOT street tires. 35 inch max. Cut tires are prohibited. No chains or studs.
Non-OEM transfer cases are prohibited. It must have been an option on a one ton or smaller pick up truck.
Transmission – Automatic:
Non-OEM transmissions are prohibited. Aftermarket torque converters, valve bodies and internal components are permitted. Factory auto shift columns only, No floor shifters. All transmission lines must be metallic or high pressure type hose. All vehicles with engines running 4500 RPM or more and using an automatic transmission must be equipped with a transmission shield meeting SFI Spec 4.1 and must be labeled accordingly. A blanket type shield is permitted. It must be appropriately labeled as meeting SFI Spec 4.1 and it must extend from the rear of the engine block to the front of the tail housing with a minimum of six (6) inch overlap where it is fastened. All non-blanket shields must incorporate two (or one per manufactures instruction) inch by 1/8 inch straps that bolt to the shield on each side and pass under the transmission pan unless the transmission pan is labeled as meeting SFI Spec 4.1. All vehicles with engines running 4500 RPM or more and using an automatic transmission must be equipped with a flex plate meeting SFI Spec 29.1 and be covered by a flex plate shield meeting SFI Spec 30.1.
Transmission – Manual:
Non-OEM transmissions are prohibited. A clutch meeting minimum SFI Spec1.1 or 2.1 is mandatory on all engines running 4500 RPM or more. All manual transmissions must be clutch assisted. Sequential shifters are prohibited. All vehicles with engines running 4500 RPM or more and equipped with a manual transmission must have a flywheel shield labeled as meeting minimum SFI Spec 6.3 or greater. Applications for which an SFI Spec flywheel shield is not available may use a properly attached SFI 4.1 or 4.2 blankets that completely cover the bell housing. It must be attached to the rear of the engine block and extend rearward to the transmission with a minimum of six (6) inch overlap where it is fastened. All transmissions or clutch pedals will have a safety interlock switch so that vehicle will not start in gear.
The vehicle is limited to a stock, unmodified, OEMI Factory charger with factory configuration only.
Water injection is prohibited. All system components must be removed from truck.
The vehicle must retain the original factory wheel base and track width. Cab and chassis trucks may not exceed 172 inches center to center of axles. Front dual-wheel spacers may be used only with accompanying positive-offset dually style wheels.
New Class for 2015, American Farm Pullers Association may change or add rules at anytime and the American Farm Pullers Association tech officials rulings are FINAL.