Piston: Service and Repair

Fig. 24 Piston Measurements:

Fig. 25 Piston Measurements:

Fig. 26 Piston Measurements:

REMOVAL
1. Remove engine from vehicle as outlined under Engine/Service and Repair then remove cylinder head and oil pan from engine as outlined under Cylinder Head/Service and Repair and Oil Pan/Service and Repair.
2. On 8.0L/V10-488 engine, remove oil pump pickup tube.
3. On all engines, cover piston, then ream ridge at top of cylinder bore with suitable reaming tool.
4. Mark connecting rod and cap for installation reference, then remove cap and install rod bolt guide set on rod bolts.
5. Rotate crankshaft until connecting rod is centered in cylinder bore at BDC, then slide piston and rod out from top of block. Do not nick crankshaft journals.
6. After assembly is removed, install cap on mating connecting rod.

INSTALLATION
1. Stagger compression ring gaps so that neither aligns with oil ring gap, then ensure oil ring expander ends are butted and rail gaps are positioned properly.

Fig. 27 Ring Gap Locations:

Fig. 28 Ring Gap Locations:

2. Immerse piston head and rings in clean engine oil, then compress rings with suitable piston ring compressor. Ensure ring positions do not change.
3. Install connecting rod bolt protectors on rod bolts with long protector on numbered side of rod, then rotate crankshaft until journal is centered under cylinder bore.
4. Insert rod and piston into cylinder bore, guiding rod end over crankshaft journal, then tap piston down in cylinder bore using a hammer handle or suitable equivalent. Ensure notch on top of piston points toward front of engine and larger connecting rod bore chamfer faces crankshaft journal fillet.
5. Install rod caps and tighten nuts to specifications.
6. On 8.0L/V10-488 engine, install oil pump pickup tube.
7. Install oil pump as outlined under Oil Pump/Service and Repair and cylinder head as outlined under Cylinder Head/Service and Repair.
8. Install engine as outlined under Engine/Service and Repair.