71696 Mercruiser HOUSING, DRIVE END

Camshaft Timing Check
Remove the rear camshaft inspection cover from the side of the engine.
Put the No. 1 piston at the top center position on the compression stroke. Refer to Finding the Top Center Position for the No. 1 Piston.
With the No. 1 piston on the compression stroke, install the crankshaft timing pin. After you install the crankshaft timing pin, remove the camshaft timing pin from the camshaft timing pin's storage positions.
Illustration 1 g01194270
Installation of camshaft timing pin
(1) Camshaft timing pin
(2) Camshaft
Install camshaft timing pin (1) through the timing pin hole and into the hole in camshaft (2). In order for the engine to be timed correctly, the camshaft timing pin must fit into the hole in the camshaft. Timing Adjustment of the Camshaft
Note: Before you make any timing adjustments, the timing must be checked in order to determine whether any adjustment is necessary. Refer to the section Camshaft Timing Check for this procedure.If the Camshaft Timing Check procedure indicates that the camshaft is not in time with the crankshaft, the camshaft drive gear must be removed and the camshaft must be rotated. Perform steps 1 through 8 if adjustment of the camshaft is necessary.
Put the No. 1 cylinder in the top center position on the compression stroke and install the crankshaft timing pin. Remove all of the valve covers.
Illustration 2 g00557720
Rocker arm shaft (typical example)
(1) Bolts
(2) Rocker arm shaft
Loosen bolts (1) that hold rocker arm shaft (2) in place, until all of the rocker arms are free from the valve bridges.
Illustration 3 g01194292
Rear end of the engine (typical example)
(3) Camshaft drive gear cover
Remove the crankshaft timing pin and camshaft drive gear cover (3) from the rear housing.
Illustration 4 g03862384
Camshaft drive gear
(4) Camshaft drive gear
(5) Bolts
(6) Bolt
(7) Washer
(8) Plate
(9) Speed/timing wheel
(10) Primary speed/timing sensor
(11) Bolts for the speed/timing wheel
Remove the speed/timing wheel (9) and the spacer from the camshaft gear by removing the 12 bolts (11).
Loosen the camshaft drive gear (4) by using the following procedure:
Use a 6V-6080 Torque Multiplier Gp and a 5P-1748 Socket and loosen bolt (6).
Remove bolt (6) and washer (7). Remove bolts (5) and plate (8).
Refer to Illustration 4. Put washer (7) between the camshaft and plate (8). Install bolt (6) finger tight.
Install bolts (5) finger tight.
Sudden movement of camshaft drive gear can occur when the camshaft drive gear is pulled off the taper of the camshaft. To prevent possibly personal injury, be sure that the bolt is installed (finger tight) to restrict the movement of the camshaft drive gear when the camshaft drive gear is pulled off of the taper of the camshaft.
Tighten bolts (5) evenly in order to pull camshaft drive gear (4) off the taper of the camshaft.
Fasten a hoist to the camshaft drive gear (4). Remove the following components: bolts (5), bolt (6), plate (8), washer (7) and camshaft drive gear (4). The weight of the camshaft drive gear is 35 kg (77 lb).
Install the crankshaft timing pin. Remove the camshaft timing pin from the storage location.
Put the camshaft timing pin in the timing pin hole, and turn the camshaft until the timing pin goes into the hole in the camshaft.
After the camshaft is in time with the crankshaft, install the camshaft drive gear (4). Use the following procedure:
Fasten a hoist to the camshaft drive gear (4). The weight of the camshaft drive gear is 35 kg (77 lb). Position the camshaft drive gear and put the plate (8) in position on the drive gear. Install bolts (5). Note: Be sure that both the gear and the camshaft tapers are clean and dry.
Assemble speed/timing wheel (9) and the spacer. The extra tooth on the speed/timing wheel must be close to primary speed/timing sensor (10). Leave the 12 bolts loose so that the speed/timing wheel can be rotated.
Illustration 5 g03862373
For clockwise rotation of gear.
(10) Primary speed/timing sensor
(12) First tooth after the extra tooth
Illustration 6 g03862374
For counterclockwise rotation of gear.
(10) Primary speed/timing sensor
(12) First tooth after the extra tooth
Rotate the speed/timing wheel until the centerline of the first tooth after the extra tooth is aligned with the centerline of the primary sensor.
Tighten the 12 bolts.
Put 4C-5593 Anti-Seize Compound on the threads of bolt (6). Install washer (7) and bolt (6). Tighten bolt (6) by hand.
Remove the crankshaft timing pin and the camshaft timing pin.
Turn the flywheel in the opposite direction of normal rotation for a minimum of 20 degrees. Note: Prelube the engine before you rotate the crankshaft in order to perform service work. Rotating the crankshaft before prelube may cause damage to the crankshaft bearings if the mating surface is dry.
Turn the flywheel in the direction of normal engine rotation until the crankshaft timing pin can be reinstalled in the crankshaft. This procedure holds the backlash in the timing gears in the direction of normal engine rotation.
If the crankshaft timing pin location is missed, do not turn the flywheel in the opposite direction in order to install the crankshaft timing pin.
Note: If the crankshaft timing pin location is missed, repeat Steps 8.g and 8.h.
Install the camshaft timing pin in order to verify the camshaft position. In order to prevent damage to the timing pins, remove the crankshaft timing pin and the camshaft timing pin