of threaded fasteners. Figure 2-l1 shows three types oftorque wrenches.To use a torque wrench, first select the proper torquevalue for the torquing procedure you are using. Next,Figure 2-10.—A typical stroboscope.Figure 2-11.—Typical torque wrenches.select the torque wrench with the correct capacity. Thetorque value should be in the second or third quarter ofthe wrench’s torque scale because the first and lastquarters of the scale are not as accurate as the middlequarters.Torque wrenches are precision tools. Handle themwith care and always follow the manufacturer’s manualwhen you use them.TORQUE MULTIPLIERTorque multipliers are geared devices attached tothe torque wrench to increase the force of torque. Themost preferred ratio of the torque multiplier is 4 to 1. Touse a torque multiplier, select one with an outputcapacity above the required torque. Be sure to follow themanufacturer’s operating manual to avoid personnelinjury and damage to the equipment.TORQUE ADAPTERSTorque adapters allow the torque wrench to be usedto tighten parts and fasteners other than standard nutsand bolts. Adapters are available in a variety of shapesgeared to the repair of different parts of the dieselengine. Several types of torque adapters are shown infigure 2-12.When you use an extension adapter, the torqueapplied to the part or fastener will be greater than thetorque indicated on the torque wrench. Therefore, youmust account for the length of the adapter to apply theproper torque to the part or fastener. Figure 2-13illustrates the points of measurement.The torque applied by the adapter is directly relatedto the length of the adapter. As the length of the adapterincreases, so does the applied torque.To determine the actual torque applied to the part orfastener, assume that the length of the torque wrench isL and the length of the adapter is A. Assume also thatTw is the torque indicated on the scale of the torquewrench and Ta is the torque exerted at the end of theadapter.To determine Ta, simply multiply the torqueindicated on the torque wrench (Tw) by the ratio of thetotal effective length of the assembly (L + A) to thelength of the torque wrench (L).or2-7
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