ISBe/ISB Series Engines – 003-004   Overhead Set

WARNING  Batteries can emit explosive gases. To reduce the possibility of personal injury, always ventilate the compartment before servicing the batteries. To reduce the possibility of arcing, remove the negative (-) battery cable first and attach the negative (-) battery cable last.

• Disconnect the batteries.

• Remove the rocker lever cover and gasket.

NOTE: Engine coolant temperature
must be less than 60°C [140°F].

NOTE: For marine engines equipped with a TDC mark on the vibration damper, use the Adjust step for All Applications Except Marine.

NOTE: For marine engines
not equipped with a TDC mark on the vibration damper, use the Adjust step for Marine Applications.

Use the barring tool, Part Number 3824591 to rotate the crankshaft until the number 1 cylinder is at TDC.

TDC can be determined by the following methods:

For 3.9 L and 5.9 L Engines without EGR, align the crankshaft speed indicator ring on the front of the crankshaft so that the unpunched area of the crankshaft speed indicator ring is at the 12-o’clock position. If both number 1 cylinder rocker levers are loose, move to the following steps. If both number 1 cylinder rocker levers are
not loose, rotate the crankshaft 360 degrees.

NOTE: The TDC indicator is on the vibration damper/crankshaft speed indicator ring.

For all 4.5 L, 5.9 L engines with EGR, and 6.7 L engines, align the vibration damper/crankshaft speed indicator ring so that the TDC indicator is at the 12-o’clock position. If both number 1 cylinder rocker levers are loose, move to the following steps. If both number 1 cylinder rocker levers are
not loose, rotate the crankshaft 360 degrees.

NOTE: If no TDC mark is present on either the vibration damper or the crankshaft speed indicator ring, align the large gap in the crankshaft speed indicator ring to the 5-o’clock position (2). The dowel pin could also be visible in the 9-o’clock position (1). Check that both number 1 cylinder rocker levers are loose. If they are
not loose, rotate the crankshaft 360 degrees and recheck.

With the engine in this position, lash can be measured on the following rocker levers:

(E = exhaust, I = Intake)

Four-cylinder 1I, 1E, 2l, and 3E:

Six-cylinder 1I, 1E, 2I, 3E, 4I, and 5E.

NOTE: The clearance is correct when some resistance is “felt” when the feeler gauge is slipped between the crosshead and the rocker lever socket.

Measure lash by inserting a feeler gauge between the crosshead and the rocker lever socket. If the lash measurement is out of specification, loosen the locknut, and adjust the lash to nominal specifications.

Tighten the locknut and measure the lash again.

Using barring tool, Part Number 3824591, rotate the crankshaft 360 degrees.

Following the same steps and specifications as previously stated, measure lash for the following rocker levers:

(E = exhaust, I = Intake)

Four-cylinder 2E, 3I, 4E, and 4I:

Six-cylinder 2E, 3I, 4E, 5I, 6I, and 6E.

Reset if out of specification.

WARNING  Batteries can emit explosive gases. To reduce the possibility of personal injury, always ventilate the compartment before servicing the batteries. To reduce the possibility of arcing, remove the negative (-) battery cable first and attach the negative (-) battery cable last.

• Install the gasket and rocker lever cover.
• Connect the batteries.

• Operate the engine and check for leaks.