Section 6A4 · Pages 391–426 (36 pages)

4.8 Liter L6 Engine

From the 1987 Chevrolet Light Duty Truck Unit Repair Manual

Bench overhaul of the GM 4.8L inline six: overhead valves, cast-iron block and head, seven main bearings with thrust at the rear and a gear-driven camshaft. Disassembly runs from accessories, the air manifold and injection tube, manifold, thermostat housing and water pump to the valve train, head, damper, oil pan and pump, timing gear cover, pistons, flywheel, crankshaft and camshaft. Inspection and repair includes main bearing cap replacement, cylinder bores, camshaft and bearings, valve train, head and the oil filter relief valve; assembly covers valve adjustment, checking valve timing and engine set-up and testing.