VALVE-RELIEF 4T1056 - Caterpillar

Overloading
The “Caterpillar 10/10/20 Payload Rule” for Off-Highway Trucks (OHT) states:
No more than 10% of the payloads may exceed 1.1 times the maximum target payload for the truck.
No single payload shall exceed 1.2 times the maximum target payload.The target payload is based on the Gross Machine Weight (GMW) of the truck. The GMW is a function of the truck configuration and includes the weight of the tires, rims, and body.Placement of the Payload
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(1) Load marker illustrated on a typical OHTEnsure that the payload weight is distributed properly in the truck body. Incorrect payload placement in the truck body can adversely affect the life of many of the truck components. Cat® trucks are designed for a GMW distribution of 33% on the front axle and 66% on the rear axle. The best way to determine the actual load placement is with a certified truck scale. Ensure that the loading bucket is positioned over the marker that is used to indicate proper load placement (1). Also, ensure that the load is centered from the side to the side in the body of the truck.Note: Older trucks may be retrofitted with a marker (1) to indicate the proper placement of the load. The 175-2624 Markers (1) are available through the machine order system. For information on proper placement of the marker on the truck body, contact your Caterpillar® Dealer. Your Caterpillar Dealer will need the following information:
Truck serial number
Truck body part number
Truck body sequence number
Truck body modification informationPayload Bias
A payload that is placed correctly in the truck body will improve the accuracy of payload measurement. The payload should be placed in the truck body so that the GMW is distributed to the axles correctly. The correct payload bias will maintain 66% of the GMW on the rear axle and 33% on the front axle. The payload bias can be determined by observing the position of the load in the truck body. Data from the suspension cylinder pressure can be used to measure the payload bias. Suspension cylinder pressure can be viewed with the Display to verify correct payload bias.Typically, most of the problems that occur with the payload are the result of improper positioning of truck under the loading tool. Payloads that are not biased correctly have the potential for causing an event to be recorded by VIMS. Hauling payloads that are biased incorrectly may reduce the truck service life.The Loading Floor
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A typical level loading floor area for an OHT
The area in which the truck is loaded is referred to as the loading floor. The loading floor should be kept as level as possible. A loading floor that does not allow the truck to sit level during loading will affect the accuracy of the payload measurement.