ARM GP-GRAPPLE 4230308 - Caterpillar

Measurement Procedure
Table 1
Required Tools
Description Qty
Plastic Gauge (Green)
0.025 to 0.076 mm
(0.001 to 0.003 inch) 1
Plastic Gauge (Red)
0.051 to 0.152 mm
(0.002 to 0.006 inch) 1
Plastic Gauge (Blue)
0.102 to 0.229 mm
(0.004 to 0.009 inch) 1
Plastic Gauge (Yellow)
0.230 to 0.510 mm
(0.009 to 0.020 inch) 1
Keep all parts clean from contaminants.Contaminants may cause rapid wear and shortened component life.
Note: Perkins does not recommend the checking of the actual clearances of the bearing shells particularly on small engines. This is because of the possibility of obtaining inaccurate results and the possibility of damaging the bearing shell or the journal surfaces. Each Perkins bearing shell is quality checked by Perkins for specific wall thickness.Note: The measurements should be within specifications and the correct bearing shells should be used. No further checks are necessary if the main journals and the bearing shells were measured during disassembly of the engine. No further checks are necessary if the crank pins of the crankshaft and the bearing shells were checked during the disassembly of the connecting rods. However, Plastic Gauge is an acceptable method if the technician still wants to measure the clearance of the bearing shell. Plastic Gauge is less accurate on journals with small diameters if clearances are less than 0.10 mm (0.004 inch).
Lead wire, shim stock or a dial bore gauge can damage the bearing surfaces.
The technician must be very careful to use Plastic Gauge correctly. The following points must be remembered:
Ensure that the backs of the bearing shells and the bores of the bearing shells are clean and dry.
If the bearing shells have locking tabs ensure that the locking tabs are properly seated in the tab grooves.
The crankshaft must be free of oil at the contact points of the Plastic Gauge.
Illustration 1 g01010832
Typical example
Put a piece of the Plastic Gauge (1) on the crown of the bearing shell that is in the cap. Note: Do not allow the Plastic Gauge (1) to extend over the edge of the bearing shell.
Use the correct torque-turn specifications in order to install the bearing cap. Do not use an impact wrench. Be careful not to dislodge the bearing shell when the cap is installed. Note: Do not turn the crankshaft when the Plastic Gauge (1) is installed.
Carefully remove the bearing cap, but do not remove the Plastic Gauge (1). Measure the width of the Plastic Gauge (1) while the Plastic Gauge is in the bearing cap or on the crankshaft journal. Refer to the Illustration 1.
Remove all of the Plastic Gauge (1) before you install the bearing cap. Note: When Plastic Gauge is used, the readings can sometimes be unclear. For example, all parts of the Plastic Gauge are not the same width. Measure the major width in order to ensure that the parts are within the specification range. Refer to the Specifications Manual, "Connecting Rod Bearing Journal" and refer to the Specifications Manual, "Main Bearing Journal" for the correct clearances.