User Manual

Page 13 of 39 DETROIT DDC-ENG-MAN-0001
II. BOTTOM PTO’s
Auxiliary equipment require power take-offs, either when the truck is stationary or when it is in motion.
Various power take-off alternatives can be chosen, depending on the bodywork. The work is generally
carried out by equipment which is powered by a hydraulic motor. The hydraulic motor, together with a pump
and associated equipment, form the basis of the hydraulic system. The pump, which provides the hydraulic
pressure and flow to the motor, is the heart of the hydraulic system. Below are some guidelines for Bottom
PTO operation with the new DT12 variants:
 PTOs are not designed to handle axial or radial forces. No direct installation of belt pulley or
sprocket on PTO output shaft is allowed.
 Due to the risk of PTO overloading, overload protection must be installed.
 Engine speed with the PTO engaged and under load must follow the instructions “Torque –
Restriction (engine speed)”.
 Whole number ratios are not acceptable because of risk to built-up resonance vibrations (contact
PTO supplier).
 Beside the torque capacity of the PTO, its retrievable output torque (lowest torque result of the
following three situations) depends on the torque reduction values for
 shock loads (dynamic torque)
 high bending angle of driveshaft
 power split
The new DT12 Bottom PTO is being released to the following DT12 variants:
 DT12-DC (DHE & DV) with Chelsea PTO’s only
 DT12-OC (OHE & OV) with both Chelsea & Muncie PTO’s
 DT12-OD (OVX) with both Chelsea & Muncie PTO’s
The following DT12 variants will only have the Rear PTO available:
 DT12-DB (DHL)
 DT12-OB (OHL)
 DT12-DA (DH)
 DT12-OA (OH)
BOTTOM PTO ROTATION DIRECTION
The direction of rotation of all Bottom PTO’s (Chelsea and Muncie) is shown below:
Figure 11: Bottom PTO rotation direction, as seen from the rear of the vehicle.