KEY 2961498 - Caterpillar

Refer to Systems Operation, Testing and Adjusting, UENR2782, "Machine Preparation for Troubleshooting" before you perform any Testing and Adjusting or troubleshooting.Prior to starting with checks on the modulating valves, use Caterpillar ET in order to diagnose any fault codes that may be present. Refer to Systems Operation, Troubleshooting, Testing and Adjusting, UENR2782, "Power Train Electronic Control System".After checking for fault codes, run a calibration of the transmission. Refer to Systems Operation, Testing and Adjusting, UENR2782, "Transmission - Calibrate".Testing The Modulating Valves
Illustration 1 g03147701
Modulating valves (Electronic Clutch Pressure Control)
(1) Pressure for clutch 3
(2) Pressure for clutch 4
(3) Pressure for clutch 1
(4) Pressure for clutch 6
(5) Pressure for clutch 5
(6) Pressure for clutch 2
(7) Torque converter inlet relief pressure The pressure test points for the transmission clutches can be found back side of the "doghouse" as shown in Illustration 1. The modulating valves (electronic clutch pressure control) are located on the right side of the transmission.With the transmission in neutral, the pressure of the oil in the transmission clutches can only be tested on clutch 1. Refer to Systems Operation, Testing and Adjusting, UENR2782, "Power Train Pressures".If the pressure for clutch 1 is correct, the oil supply to the modulating valves (electronic clutch pressure control) is sufficient.The pressure in the other transmission clutches can only be tested with the output flange moving.If the transmission is observed to slip in one gear, a transmission clutch may not be functioning correctly.Use Table 1 in order to determine the transmission clutch that may not be functioning correctly.
Table 1
CX48-P2300 Transmission Clutch Assignments
Operation Gear Ratios CLUTCHES Transmission Output Speed at 800 RPM Input with LUC Engaged (RPM) Transmission Output Speed at 1900 RPM Input with LUC Engaged (RPM)
1 2 3 4 5 6
Stall − O O O − −
Park − O O − −
Neutral − O − −
1 Forward 3.339 O O 240 569
2 Forward 2.453 O O 326 775
3 Forward 2.200 O O 364 864
4 Forward 1.808 O O 442 1051
5 Forward 1.616 O O 495 1176
6 Forward 1.359 O O 589 1398
7 Forward 1.191 O O 672 1595
8 Forward .999 O O 801 1902 Testing The Solenoid Coil Assembly
The function of the solenoids can be tested by running a calibration of the transmission. The ability to monitor pressures in the clutches when a calibration sequence is being run is possible. The calibration will also alert the operator to any faults that are detected with the transmission clutches.Note: The pressures that can be observed during a calibration are not the full pressures of a clutch engagement. Use a 0 to 689 kPa (0 to 100 psi) gauge to measure the pressures. From the pressures that are observed, the ability to determine if