DRIVE GP-FINAL 1564114 - Caterpillar

The new motors are adaptable to all previous machines for the listed models. When the motors are replaced, the propel synchronization procedure in the service manual is no longer valid. Follow the procedure below to synchronize the new drum and axle motors.
Procedure To Synchronize Propel And Drum Motors With Maximum Displacement Adjustment Capacity
This test must be performed outside in an area clear of any obstacles and personnel. Before performing the synchronization test the maximum displacement screws should be preset. Testing has shown that pre-setting the maximum and minimum displacement screws to the dimensions shown in illustrations (1) and (2) should result in both systems being synchronized.
Illustration 1: Axle Motor.(A) 27 mm (1.053 in.).(B) Maximum adjustment screw.(C) Minimum adjustment screw.(D) 19 mm (.741 in.).
Illustration 2: Drum Motor.(E) 21 mm (.826 in).(F) Minimum adjustment screw.(G) Maximum adjustment screw.(H) 14 mm (.551 in).
Illustration 3: Test Port Connections.(1) Drum forward pressure tap.(2) Drum reverse pressure tap.(3) Axle forward pressure tap.(4) Axle reverse pressure tap.1. Connect a 60,000 kPa (8700 psi) pressure gauge to drum forward tap (1), drum reverse pressure tap (2), axle forward pressure tap (3) and axle reverse pressure tap (4) (a total of four gauges). Mark each gauge to indicate which circuit it is measuring. Use extension hoses with enough length to read the gauges from the operator's seat.2. Start and run the engine at high idle until the hydraulic system temperature reaches 38°C (100°F). The engine speed at high idle should be 2350 50 rpm.3. Move the speed selection switch to the LOW speed position.4. Release the parking brake and move the propel lever FORWARD to a point approximately half-way between neutral and fill speed. Record the reading of the gauges connected to drum forward pressure tap (1) and axle forward pressure tap (3).5. Move the propel lever in REVERSE to a point approximately half-way between neutral and full speed. Record the reading of the gauges connected to drum reverse pressure tap (2) and axle reverse pressure tap (4).6. Move the speed selector switch to the HIGH speed position.7. Release the parking brake and move the propel lever FORWARD to a point approximately half-way between neutral and full speed. Record the reading of the gauges connected to the drum forward pressure tap (1) and axle forward pressure tap (3).8. Move the propel lever in REVERSE to a point approximately half-way between neutral and full speed. Record the reading of gauges connected to drum reverse pressure tap (2) and axle reverse pressure tap (4). The following values are shown for example only. The actual pressures will vary depending upon soil type and condition. 9. In the same direction and travel speed range, the pressure differential between the drum and axle motor circuits should be within 1375 kPa (200 psi). Perform the following procedures in accordance with the pressure readings.Differential Pressure Is Greater Than 1375 kPa (200) PSI In BOTH Speed Ranges.
Remove linkage (5) between the two manual displacement control levers (see illustration 3). Internal springs will hold each