55778A 3 Mercruiser GEAR KIT (1.98 RATIO) (20-24 GEAR RATIO)

Table 1
Required Tools
Tool Part Number Part Description Qty
A 473-2944 Capping Kit 1
B 438-6765 Plug 1
Keep all parts clean from contaminants.Contaminants may cause rapid wear and shortened component life.
Care must be taken to ensure that fluids are contained during performance of inspection, maintenance, testing, adjusting and repair of the product. Be prepared to collect the fluid with suitable containers before opening any compartment or disassembling any component containing fluids.Dispose of all fluids according to local regulations and mandates.
Turn the battery disconnect switch to the OFF position.
Drain the coolant from the cooling system into a suitable container for storage or for disposal. Refer to Operation and Maintenance Manual, "Cooling System Coolant - Change" for the correct draining procedure.
Remove the Diesel Exhaust Fluid (DEF) line from the DEF injector. Refer to Disassembly and Assembly, "Diesel Exhaust Fluid Lines - Remove and Install" for the correct procedure.
Illustration 1 g06465444
Typical example
Disconnect harness assembly (3) from the DEF injector. Cap the harness assembly.
Use Tooling (B) to plug connection on DEF injector (2).
Disconnect hose assemblies (1) from DEF injector (2). Use Tooling (A) to cap hose assemblies (1) and DEF injector (2).
Illustration 2 g06465797
Illustration 3 g06465802
Remove nuts (4) and washers (5) from DEF injector (2).
Remove DEF injector (2) and gasket (6) from the Clean Emission Module (CEM). Use a suitable plug to plug the CEM.Note: Note the orientation of gasket (6) for installation purposes only.
Remove seal (8) from DEF injector (2).
Remove studs (7) from the CEM.Installation Procedure
Table 2
Required Tools
Tool Part Number Part Description Qty
C - Bostik Pure Nickel
Anti-Seize Compound 1
Ensure that all components are clean, and free from wear and damage. If necessary, replace any components that are worn or damaged.
Illustration 4 g06465809
Illustration 5 g06465806
Follow Step 2a through Step 2c to install new studs (7) to the CEM.
Apply Tooling (B) to the end of studs (7).
Install the short threaded end of studs (7) to the CEM.
Tighten studs (7) to a torque of 5 N m (44 lb in).
Clean the gasket surface in Position (W) on the CEM. Ensure that no debris enters the CEM.
Clean the gasket surfaces in Position (Y) on DEF injector (2). Ensure that no debris enters the orifice plate in Position (X).
Position a new gasket (6) onto the CEM. Ensure that the metal section of the gasket, faces the gasket surface in Position (W) on the CEM.
Install a new seal (8) onto DEF injector (2). Ensure that the gasket is correctly seated.
Apply Tooling (B) to the threads of studs (7).
Remove the plug from the CEM. Install DEF injector (2) to the CEM.Note: To maintain cleanliness, the protective caps must remain in place until the final fluid connections are made.
Install washers (5) to studs (7).
Install new nuts (4) to DEF injector (2) hand tight.
Tighten nuts (4) to a torque of 5 N m (44 lb in).
Turn nuts (4) through an additional 90 degrees.
Illustration 6 g06465444
Typical example
Remove caps from hose assemblies (1) and DEF injector (2).
Connect hose assemblies (1) to DEF injector (2). Ensure that the hose assemblies are installed onto the hose assemblies original positions.
Remove the cap from harness assembly (3). Remove the plug from DEF injector (2).
Connect harness assembly (3) to DEF injector assembly (2). Ensure that the harness assembly is not strained.
Install the Diesel Emission Fluid (DEF) line to the Diesel Emission Fluid (DEF) injector. Refer to Disassembly and Assembly, "Diesel Exhaust Fluid Lines - Remove and Install" for the correct procedure.
Fill the cooling system to the correct level. Refer to Operation and Maintenance Manual, "Cooling System Coolant - Check" and refer to Operation and Maintenance Manual, "Cooling System Coolant - Change" for the correct filling procedure.
Turn the battery disconnect switch to the ON position.