9148A27 Mercury GEAR HOUSING (X-LONG) (BLACK)

Engine Rotation
When you view the engine from the flywheel end, The SAE standard engine crankshaft rotation is counterclockwise.Note: The front end of the engine is opposite the flywheel end of the engine.The left side and the right side are viewed from the flywheel end of the engine.Engine Prelubrication
Many service and inspection procedures require rotation of the engine crankshaft. The prelubrication of the engine is required when the crankshaft is rotated during normal maintenance operations. This includes adjusting the valves and starting the engine.The push button for the engine prelube is at the lower left-hand corner of the panel for the Engine Supervisory System. The push button provides a manual method to prelube the engine.DO NOT use the air or electric starting motors to rotate the engine. If the engine is rotated too fast, oil from the prelube pump will not be enough to protect the engine.Use the manual barring group to rotate the crankshaft for service work. Leave the prelube pump on during the time of crankshaft rotation. Damage can result if the crankshaft is rotated on dry bearing surfaces.
In order to avoid possible damage to the engine, the prelube pump should not be operated continuously for extended periods of time. During repairs, if the prelube pump has run for more than three hours continuously, any oil that may have collected in the cylinders and/or above the valves should be removed before attempting to start the engine.
Finding The Top Center Compression Position For No. 1 Cylinder
Illustration 1 g00311103
Location of the timing pin
(1) Manual barring group
(2) Storage position of the timing pin
Remove the crankshaft timing pin from the storage position (2). The storage position of the timing pin is located below the manual barring group (1). The manual barring group is on the right side of the rear housing.
Illustration 2 g00311105
Installation of the crankshaft timing pin
(3) Flywheel timing bracket
(4) Mounting bracket for the timing pin
(5) Timing pin
Use the manual barring group to turn the engine flywheel in the direction of normal engine rotation. Turn the engine until the crankshaft timing pin (5) can be installed through mounting bracket (4) for the timing pin . Ensure that the timing pin is engaged in flywheel timing bracket (3).Note: If the flywheel is turned beyond the point of installation in the flywheel timing bracket, the lash must be removed from the timing gears. Turn the flywheel in the opposite direction of normal rotation for approximately 20 degrees. Then turn the flywheel in the direction of normal engine rotation until the timing pin can be installed in the bracket assembly. This procedure ensures that the lash is removed from the timing gears.Note: If the No. 1 cylinder is at TC, the hole for the crank angle sensor in the flywheel will be positioned directly opposite the crank angle sensor (CAS).
Remove the valve cover from the No. 1 cylinder head.
The inlet and exhaust valves for the No. 1 cylinder are fully closed if No. 1 piston is on the compression stroke and the rocker arms can be moved by hand. If the rocker arms cannot be moved and the valves are slightly open, the No. 1 piston is on the exhaust stroke. When the timing pin has been installed in the crankshaft, refer to Table 1 to determine the correct cylinders that need to be checked and/or adjusted for the stroke position of the crankshaft.Note: When the actual stroke position is identified and the other stroke position is needed, remove all timing pins from the engine. Turn the flywheel for 360 degrees in the direction of the normal rotation of the engine.
Illustration 3 g00283190
G3606 cylinder and valve location
(A) Inlet valve
(B) Gas admission valve
(C) Exhaust valve
Illustration 4 g00465539
G3608 cylinder and valve location
(A) Inlet valve
(B) Gas admission valve
(C) Exhaust valveCamshaft Timing Check
Remove rear camshaft inspection covers from both sides of the engine.
Put the No. 1 piston at the Top Center Position on the compression stroke.
When the crankshaft timing pin is installed and the No. 1 piston is on the compression stroke, remove the camshaft timing pin from the storage position.
Illustration 5 g00311143
Installation of camshaft timing pin
(1) Timing pin
(2) Camshaft
Install timing pin (1) through the timing pin hole and into the hole in camshaft (2).
If the timing pin does not go into the hole in the camshaft, the engine is not timed correctly and the camshaft position must be adjusted. Refer to the section "Camshaft Timing Adjustment".Camshaft Timing Adjustment
Note: Before your perform any timing adjustments, check the timing to ensure that an adjustment is necessary. Refer to "Camshaft Timing Check".If the camshaft is not timed with the crankshaft, the camshaft drive gear must be removed and the camshaft must be rotated. Follow Steps 1 through 7 if adjustment of the camshaft is necessary.
Put the No. 1 cylinder in the TC position of the compression stroke and install the crankshaft timing pin. Remove all the valve covers from the side of the engine that requires adjustment.