Bore Gauge Method - Ford LRG-423 Service Manual

01-20 Engine Service
01-20
SERVICE PROCEDURES (Continued)
A233390A
Item
Part
Number
Description
1
D81 L-6002-B
Plastigage@
2 - Plastigage@ Scale
(Part of 081 L-6002-B)
A - Check Width of Plastigage@
B - Location of Plastigage@
Prior to Tightening
4.
Install cap and tighten bolts to specification. Do
not turn crankshaft while Plastigage@ is in place.
5. Remove cap. Using Plastigage@ scale, check
width of Plastigage@ at widest point to get
minimum clearance. Check at narrowest point to
get maximum clearance. Difference between
reading is taper of journals.
6. If bearing clearance exceeds the specified limits,
try using one of the various combinations of
undersize bearings as directed by the
accompanying table. Use of any other bearing
combination is not recommended. Bearing
clearance must be within specified limits.
Refer to specifications in specification section for
main and connecting rod bearing clearance
limits. If use of these bearing combinations does
not bring clearance to the desired limits, refinish
the crank journal to a standard undersize, and
use the appropriate undersize bearing.
7.
After bearing has been fitted and cleaned, apply
a light coat of engine oil to journal and bearings.
Install bearing cap. Tighten cap bolts to
specifications found in the specifications section.
8. Repeat procedure for remaining bearings that
require replacement.
Bore Gauge Method
1.
2.
3.
4.
5.
6.
7.
8.
Install bearings in the cylinder block (6010) and
bearing caps.
Install crankshaft and tighten main bearings cap
bolts to the specified torque as outlined in Section
02.
Remove bearing caps and crankshaft.
Reinstall bearing caps with bearings still installed
in cylinder block and caps.
Tighten bearing cap bolts to torque specified in
Section 02.
Using micrometer, measure main bearing
journals as outlined in this section.
Using bore gauge, measure the inside diameter
of each bearing assembly. It may be necessary to
measure the outer bearings first, then remove
those caps and measure the inner bearings.
Subtract the maximum measurement for each
journal from the minimum measurement of each
bearing to determine the minimum oil clearance.
Allowable bearing clearances are:
Number one main bearing 0.01 O-0.054mm (0.0004-
0.0021 in.). Numbers two to five main bearings 0.020-
0.064mm (0.0008-0.0025 in.).
,
For This Amount
of Bearing
Clearance Excess
mm inch
0.0-0.013
0.0-0.0005
0.013-0.026 0.0005-0.0010
0.026-0.039
0.0010-0.0015
0.039-0.052 0.0015-0.0020
Use This Bearing Size
(Upper Bearing) (Lower Bearing)
mm inch mm inch
0.025 0.001 U.S. Standard
Standard
0.025 0.001 U.S.
0.025 0.001 U.S.
0.050
0.002 U.S. 0.025 0.001 U.S.
0.050 0.002 U.S.
0.050 0.002 U.S.