TM-9-2320-272-23-3
TRUCK, 5-TON, 6X6, M939, M939A1, AND M939A2 SERIES TRUCKS (DIESEL)
TECHNICAL MANUAL; FIELD MAINTENANCE MANUAL; VOLUME 3 OF 5
SEPTEMBER 2012
TM-9-2320-272-23-3 - Page 334 of 1469
AUTOMATIC SHIFT SPEED TEST
1.
Road test vehicle and record engine rpm at shift points (TM 9-2320-272-10).
2.
With vehicle in operation, shift transmission through the range sequence. See table for lever range sequence.
3.
Check recorded engine shift point rpm with table.
4.
If shift points are incorrect, check modulator adjustment. If modulator adjustment does not correct shift speed,
repair transmission as necessary.
Table
1.
Transmission Shift Point Check.
SELECTOR
LEVER RANGE
THROTTLE
AUTOMATIC
SHIFTING
ENGINE (RPM)
1-2
Fully open
1-2
1,900 to 2,050
2-2
1,900 to 2,050 (before converter lock-in)
2-2
1,600 to 1,825 (after converter lock-in)
1-3
2-3
2,000 to 2,150
1-4
3-4
2,030 to 2,140
1-5 (drive)
4-5
2,015 to 2,130
END OF TASK
TM 9-2320-272-23-3
0374
0374-15
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