PLATE 3599494 - Caterpillar

Selecting the Correct Cylinder Head Gasket
Illustration 3 g02902277
(a) 2 Notches
(b) 1 Notch
(c) Without Notch
Make sure to note the notch (a), (b), or (c) of cylinder head gasket in advance.
Replace the same notch (a), (b), or (c) as the original cylinder head gasket.
When replacing the piston, piston pin bushing, connecting rod or crank pin bearing, select the cylinder head gasket thickness to meet with the top clearance.
Illustration 4 g02902343
Measure the piston head protrusion or recessing from the crankcase cylinder face 4 spots per each piston using the dial gauge as shown in figure, and get the average of the measurements.
Use the table below to select an applicable cylinder head gasket.
Table 2
Head Gasket Notch Head Gasket Thickness Piston head protrusion or recessing from crankcase cylinder face
Before Tighten After Tighten
(a)-two notches 0.900 mm (0.0354 inch) 0.800 mm (0.0315 inch) 0.0775 to 0.150 mm (0.00305 to 0.00591 inch)
(b)-one notch 1.00 mm (0.039 inch) 0.900 mm (0.0354 inch) 0.150 to 0.250 mm (0.0059 to 0.0098 inch)
(c)-without notch 1.10 mm (0.043 inch) 1.00 mm (0.039 inch) 0.250 to 0.343 mm (0.0098 to 0.0135 inch) Top Clearance
Remove the cylinder head.
Illustration 5 g02908085
(3) Plastigauge
With the piston at TDC, use grease to affix three or four Plastigauge of a diameter 1.5 mm (0.059 inch) by 5.0 to 7.0 mm (0.20 to 0.27 inch) long to the crown of the piston; keep the gauges away from the intake valve and combustion chamber fittings.
Take the piston to an intermediate position, install the cylinder head, and tighten the head bolts to the specified torque.
Turn the crankshaft so the piston goes through TDC.
Illustration 6 g02908096
(4) Crushed Plastigauge
(5) Scale
Remove the cylinder head and compare the width of the crushed Plastigauge with the scale.
Table 3
Top clearance Factory Specification 0.60 to 0.80 mm 0.024 to 0.031 inch
If they are out of spec, check the oil clearance of the crank pin, journal, and piston pins.Cylinder Head Surface Flatness
Clean the cylinder head surface.
Illustration 7 g02908237
Illustration 8 g02908396
Place a straightedge on the cylinder head's four sides “A”, “B”, “C” and “D” and two diagonal “E” and “F”as shown in the figure. Measure the clearance with a feeler gauge.
Table 4
Cylinder head surface flatness Allowable limit 0.05 mm 0.002 inch Glow Plug
Illustration 9 g03362373
(1) Glow plug
(A) View of good glow plug
(B) View of bad glow plug
Table 5
Glow Plug 7.7 N m (68.15078 lb in) to 9.3 N m (82.31198 lb in)