SERVICE MANUAL NUMBER 26
181 CID (3.0L) 4 CYLINDER GM ENGINE
Connecting Rod Bearings
Connecting rod bearings are of the precision insert type and do not use shims for adjust-
ment. DO NOT FILE RODS OR ROD CAPS. If clearances are found to be excessive, a new
bearing will be required. Service bearings are available in standard size and .001 in. and
.002
.020
in. undersize for use with new and used standard size crankshafts, and in .010 in. and
in. undersize for use with reconditioned crankshafts.
On removing a connecting rod cap, it is possible to find a .010 in. undersize bearing. These
are used in manufacturing for selective fitting.
Inspection and Replacement
IMPORTANT: Before you remove the connecting rod cap, mark the side of the rod and
cap with the cylinder number to assure matched reassembly of rod and cap.
1.
2.
Remove connecting rod cap and bearing.
Inspect bearing for evidence of wear or damage. Defective bearings should not be
installed. Typical bearing failures are shown under “General.”
3.
4.
Wipe bearings and crankshaft clean of oil.
Measure crankpin for out-of-round of taper with a micrometer. If not within specifica-
tions, replace or recondition crankshaft. If within specifications and new bearing is to be
installed, measure maximum diameter of crankpin to determine new bearing size
required.
5.
If within specifications, measure new or used bearing clearances with gauging plastic.
IMPORTANT: If bearing is fitted to out-of-round crankpin, br sure to fit maximum
diameter of crankpin. If bearing is fitted to minimum diameter, and crankpin is
out-of-round .001 (0.02 mm), interference between bearing and crankpin will result
in rapid bearing failure.
a. Place a piece of gauging plastic the full width of crankpin (parallel to crankshaft).
b. Install bearing connecting rod and cap.
c. Place a piece of gauging plastic the length of the bearing (parallel to the crankshaft)
on the crankpin or bearing surface as shown. Position the gauging plastic in the
middle of the bearing shell. Bearings are eccentric and false readings could occur
if placed elsewhere.
a
72361
a - Gauging Plastic
d. Install the bearing in the connecting rod and cap.
Index
90-861329--1
MARCH 1999
Page 3A-47
| Categories | Mercury MerCruiser Manuals |
|---|---|
| Tags | Mercury MerCruiser 181 CID |
| Model Year | 1998, 1999, 2000, 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009, 2010, 2011 |
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|
| Document File Type | |
| Copyright | Attribution Non-commercial |
(6 votes, average: 5 out of 5)
Marine readers have rated Mercury MerCruiser GM 4 Cylinder 181 cid 3.0L Marine Engines Service Manual Number 26 5.0 out of 5.0 based on 6 product reviews. Thanks for sharing this material. Helps a lot after suffering with bad mechanics. spend too much money and nothing very good
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Great resource. Excellent information provided.
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