B150 1/2 Ton Van V6-239 3.9L (1989)
Piston: Service and Repair
Fig. 25 Oil Ring Installation
Fig. 26 Piston Measurements 3.9L/V6-238 & 5.2L/V8-318 ENGINES
When installing piston and rod assemblies in the cylinders, the compression ring gaps should be staggered and not in line with the oil ring gap. Ensure oil
ring expander ends are butted and the rail gaps are located as shown in Fig. 25.
Immerse the piston head and rings in clean engine oil and, with a suitable piston ring compressor, insert the piston and rod assembly into the bore. Tap
the piston down into the bore, using the handle of a hammer.
Assemble and install the pistons and rods with the notch or groove on top of pistons pointing toward front of engine and the larger chamfer of the
connecting rod bore installed toward crankshaft journal fillet.
Refer to Fig. 26, for piston specifications.
