3500 Generator Set Engines Caterpillar

Illustration 1	g00896277

This piston has a Keystone style top and Keystone style intermediate rings. The 1U-6431 Keystone Piston Ring Groove Gauge is necessary for measuring the ring grooves. For correct use of the gauge group, see the instruction card that is with the gauge group.

(1) Top ring

Install the top ring with the "Up-1" side toward the top of the piston.

When the piston ring is installed in a cylinder liner with a bore size of 170 mm (6.7 inch), the clearance between the ends of the piston ring is the following value. ... 0.80 ± 0.20 mm (0.031 ± 0.008 inch)

There is an increase in the clearance between the ends of the piston ring. For each 0.03 mm (0.001 inch) increase in the ring clearance, the cylinder liner bore size increases by the following value. ... 0.08 mm (0.003 inch)

(2) Intermediate ring

Install the intermediate ring with the "Up" side toward the top of the piston.

When the piston is installed in a cylinder liner with a bore size of 170 mm (6.7 inch), the clearance between the ends of the piston ring is the following value. ... 0.80 ± 0.20 mm (0.031 ± 0.008 inch)

There is an increase in the clearance between the ends of the piston ring. For each 0.08 mm (0.003 inch) increase in the ring clearance, the cylinder liner bore increases by the following value. ... 0.08 mm (0.003 inch)

(3) Oil control ring

Install the oil control ring so that the gap in the spring is 180 degrees away from the gap in the ring. The white portion of the spring must be visible at the ring end gap.

Width of groove in piston for the new piston ring ... 5.050 ± 0.010 mm (0.1988 ± 0.0004 inch)

Thickness of new piston ring ... 4.954 ± 0.019 mm (0.1950 ± 0.0007 inch)

Clearance between groove and new piston ring ... 0.067 to 0.125 mm (0.0026 to 0.0049 inch)

When the piston ring is installed in a cylinder liner with a bore size of 170 mm (6.7 inch), the clearance between the ends of the piston ring is the following value. ... 0.70 ± 0.19 mm (0.028 ± 0.007 inch)

There is an increase in the clearance between the ends of the piston ring. For each 0.03 mm (0.001 inch) increase in ring clearance, the cylinder liner bore increases by the following value. ... 0.08 mm (0.003 inch)

(4) Piston pin bore

Measure the pin bore in two places.

Take one measurement within the minor diameter.

Move laterally and take another measurement within the minor diameter.

Take the measurements close to the center of the pin bore.

Do not take the measurements on the outside edges.

Minor pin bore diameter ... 70.003 ± 0.005 mm (2.7560 ± 0.0002 inch)

Pin

Measure the pin diameter on each end in a vertical and horizontal direction.

Pin diameter ... 69.962 ± 0.005 mm (2.7544 ± 0.0002 inch)

(5) Retainer

Assemble the retainer with the opening above line A-A.