TM-9-2320-272-23-2

TRUCK, 5-TON, 6X6, M939, M939A1, AND M939A2 SERIES TRUCKS (DIESEL)

TECHNICAL MANUAL; FIELD MAINTENANCE MANUAL; VOLUME 2 OF 5

SEPTEMBER 2012

TM-9-2320-272-23-2 - Page 497 of 1417

IN-CHASSIS RUN-IN - Continued

NOTE

Coolant should not exceed 195°F (90°C) or drop below 175°F (79°C).

7.

Check engine idle speed. If idle speed is not 550 to 650 rpm on M939A2 series vehicles, perform Steps (14)

through (18).

8.

Break special seal (Figure 28, Item 2) and remove pipe plug (Figure 28, Item 3) from governor spring pack

cover (Figure 28, Item 4). Discard special seal.

9.

Using spring pack tool, turn adjusting screw (Figure 28, Item 5) in to increase idle speed; out to decrease idle

speed. Correct idle speed is 625 ± 25 rpm.

10.

Install pipe plug (Figure 28, Item 3) on spring pack cover (Figure 28, Item 4).

11.

Thread wire of special seal (Figure 28, Item 2) through pipe plug (Figure 28, Item 3) and two hex-head cover

screws (Figure 28, Item 1), and twist wire of special seal (Figure 28, Item 2) until secure.

TM 9-2320-272-23-2

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