797 Off-Highway Truck Power Train Caterpillar

Create a Test Group on Caterpillar Electronic Technician (ET)

1. On the ET screen toolbar, click File - Select ECM, and choose Transmission ECM.

2. In the status group, create a new group name entitled "797 Torque Converter Test".

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Illustration 1	g00984062

3. Select the items on the ET screen, as shown in Illustration 1.

Testing the Torque Converter

1. Perform the torque converter tests that are listed in Table 1.
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   Table 1

   TEST	SPECS	ACTUAL
   Torque Converter Oil Temperature (during tests)	> 80 °C (176 °F) < 121 °C (250 °F)
   Torque Converter Charging Filter Restriction	Max restriction 345 ± 21 kPa (50 ± 3 psi)	Low idle: High idle:
   Torque Converter Inlet Relief Pressure Measured at pressure tap "P1"	Low idle 140 ± 70 kPa (20 ± 10 psi) High idle 690 ± 70 kPa (100 ± 10 psi)	Low idle: High idle: Stall:
   Torque Converter Outlet Relief Pressure Measured at pressure tap "P1"	Low idle 100 ± 70 kPa (15 ± 10 psi) High idle 450 ± 70 kPa (65 ± 10 psi)	Low idle: High idle: Stall:
   Torque Converter Stall RPM (1)	1530 ± 65 RPM
   Transmission Charge Pressure	Low idle 2340 ± 275 kPa (340 ± 40 psi) High idle 2585 ± 170 kPa (375 ± 25 psi)	Low idle: High idle:
   Lockup Clutch Maximum Pressure NEUTRAL/CONVERTER DRIVE/HIGH IDLE	0.0 ± 35 kPa (0.0 ± 5 psi)
   Lockup Clutch Maximum Pressure NEUTRAL/DIRECT DRIVE/LOW IDLE (2)	1930 ± 140 kPa (280 ± 20 psi)

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   ( 1 )	Torque Limiting strategy reduces engine RPM.
   ( 2 )	Use Transmission Calibration Procedure