ELBOW 2780245 - Caterpillar

Introduction
The Rear Power Take-Off (RPTO) is an integral part of the flywheel housing; and is positioned approximately at the 1 o'clock position (when viewed from the rear of the engine). It provided continuous live power through a series of three direct drive gears (crankshaft gear, idler gear, and output shaft) that are driven off the rear of the crankshaft. A 1.3:1 and a 1:1 ratio RPTO unit is available. The 1.3:1 RPTO has a 30 percent increase in shaft output speed compared to the 1:1 RPTO ratio. This allows for the use of a smaller, less expensive hydraulic pump. The 1.3:1 output shaft extends 106.07 mm (4.176 in) beyond the bearing carrier. The 1:1 output shaft extends 94.06 mm (3.703 in) beyond the bearing carrier. Engine length is increased about 89 mm (3.5 in) and approximately 72.5 kg (160 lb) is added to the engine weight. The 1.3:1 unit has a drilled and plugged port located behind the right engine support pad.The gear train and spline design is capable of handling up to 1108 N m (815 lb ft) of torque throughout the full engine speed range (idle to rated rpm). The 1.3:1 RPTO output shaft will rotate 1.3 times for each engine revolution. The 1:1 RPTO output shaft turns at engine speed. The output shaft endplay is controlled with a rotating thrust plate and two stationary hydrodynamic thrust washers.Pressure lubrication in the 1:1 RPTO is supplied externally through a hose in the top of the flywheel housing. The 1.3:1 RPTO does not use an external lubrication line. Oil is pressure fed through drilled passages in the flywheel housing and shafts to lubricate all bearing and thrust surfaces. The RPTO gear surfaces are splash lubricated. No additional preventive maintenance or adjustment is necessary with the RPTO.The RPTO design allows for use of the 9S9082 Engine Turning Tool from the right-hand side of the flywheel housing. However, the timing bolt location is on the left-hand side of the flywheel housing and the 7X0870 Bolt from the timing tool cover is the correct length to be use as the timing pin. The standard attachment 3176 flywheels have a second offset timing hole for use with the RPTO.