Isuzu 20LE - Bearing Free Play Measurement; Plastigage Method

ENGINE MECHANICAL (C22NE, 22LE, 20LE) 6A-59
Inspection
Out-of-round (run-out)-middle bearing shell removed when
mounting on front and rear bearing.
Permissible out-of-round - see "Technical Data"
Bearing Free Play Measurement
Two methods for measuring bearing free play are described -
1. Plastigage method and 2. micrometer and gauge method.
The two procedures are suitable for measuring both con-rod
and main bearing free play.
For both methods ensure con-rod and main bearing caps are
identified (1) prior to removal as they are machine matched.
1.Plastigage Method
Removal
1. Remove bearing cap and shell.
2. Lightly coat journals and bearings with engine oil to
prevent Plastigage from tearing when cap is removed.
Installation
1. Lay a length of Plastigage across width of crank pin and
fit bearing cap and shell using old bolts at this stage.
Important!
Do not allow crankshaft to rotate.
Torque - Angle Method
Main bearing cap bolt - 60 N⋅m (6.1 kgf⋅m) +40° + to 50°.
Con-rod bearing cap bolts - 35 N⋅m (3.6 kgf⋅m) +45°.
Removal
1. Remove bearing cap and shell.
Measure
Width of Plastigage -use scale supplied with Plastigage.
If con-rod bearing clearance exceeds 0.031mm/0.001in or
main journal bearing clearance exceeds 0.04mm/0.02in. -
check crankshaft journal diameters - see corresponding
operation.
Replace bearing if crankshaft is within specification - see
"Technical Data"