Main Bearings, Without Crankshaft Removed; Installation - Mercury MerCruiser Service Manual

Engine Inspection and Assembly

Main Bearings, Without Crankshaft Removed

Installation

1. Remove the cap on the main bearing requiring replacement.
2. Remove the bearing from the cap.
3. Install the main bearing remover and installer tool in the oil hole in the crankshaft journal. If this tool is not available, a
cotter pin may be bent as shown and used.
Description
Kent‑Moore main bearing remover and installer tool
4. Rotate the crankshaft clockwise as viewed from the front of the engine. This will roll the upper bearing out of the engine
block.
5. Lubricate a new upper bearing.
6. Insert the plain (unnotched) end between the crankshaft and the indented or notched side of the engine block.
7. Rotate the bearing into place and remove the tool from the oil hole in the crankshaft journal.
8. Lubricate a new lower bearing and install in the bearing cap.
Tube Ref No.
Lubriplate SPO 255
136
9. Install the main bearing cap in the original location with the markings pointing toward the front of the engine.
a
10. Tighten all main bearing caps, except the rear main bearing cap.
Description
Crankshaft main bearing cap bolt—preferred method
11. Tighten the rear main bearing cap. Using the method described below.
Preferred Method:
Page 3B-68
b
a
Description
© 2016 Mercury Marine
6379
Where Used
Upper and lower bearing
b
55071
Nm
25
First torque
Final torque
90-8M0099748 eng DECEMBER 2015
a - Main bearing remover and
installer tool
b - Cotter pin
Part Number
J8080
Part No.
Obtain Locally
a - Main bearing cap
b - Bearing cap marks
lb‑in. lb‑ft
– 18.4
+90°