Case Puma 170, 185, 200, 215, 230 CVT Tractor Service Manual

Table of Contents

1. Introduction
2. Engine
3. Clutch
4. Transmission
5. Four Wheel Drive
6. Front Axle
7. Rear Axle
8. Power Take Off
9. Brake and Controls
10. Hydraulic Systems
11. Pneumatic System
12. Hitches, Drawbars and implement couplings
13. Frames and ballasting
14. Steering
15. Wheels
16. Cab climate control
17. Electrical System
18. Platform, cab, bodywork and decals

Manual Extract: Electric PTO Speed Shift

The electric shift system replaces the PTO speed selecting lever with a rotary three position switch to select the required PTO speed. The speed change switch is located near the right hand side C pillar of the tractor cab.

The electric speed selecting system replaces the control lever in the cab with a switch and motor coupled via a gearbox and worm drive system. The worm drive moves a carriage that has the Bowden cable attached to it, the motor can be driven in either direction using a H configuration relay drive system, so the PTO speed may be changed from low speed to N to high speed or vice versa as required. The motor drive system senses the current through the motor and has a Hall effect position sensor that is connected to the moving carriage within the electric shift unit.

To select the high PTO speed the motor is driven to a position approximately 200 A to D counts ( 0.97v or 19%) greater than the fully retracted position, acquired during the PTO shift mechanism calibration process; the drive current is also checked to ensure that it is lower than a preset level which occurs when the selector mechanism is in the detented position for the required speed.

To select the low PTO speed the cable is driven to a position approximately 200 A to D counts ( 0.97v or 19%) less than the fully extended position limit, acquired during the PTO shift mechanism calibration process, the drive current is checked to ensure that it is at or lower than a preset level which occurs when the selector mechanism is in the selected gear detented position.

Mechanical layout of the PTO speed change lever on the transmission case.