Forklift Bearing

Forklift Engine Bearings: Main, Connecting Rod & Thrust Bearing Sets for Xinchai 490 6102 Dachai 498

Engine bearings are the precision half-shell inserts that line the crankshaft main bearing journals and connecting rod big-end bores, providing the low-friction bearing surface between the rotating crankshaft and the stationary engine block and connecting rods. Each bearing shell is a multi-layer component — a steel backing for strength, a copper-lead or aluminum intermediate layer for load capacity, and a thin babbit or polymer overlay for embeddability and seizure resistance. The bearing does not actually contact the crankshaft journal during normal operation — a hydrodynamic oil wedge forms between the journal and bearing surface at sufficient RPM, and the crankshaft floats on a film of pressurized oil approximately 0.001-0.003 inches thick. A worn bearing with excessive clearance cannot maintain this oil film, resulting in metal-to-metal contact that destroys the bearing and scores the crankshaft journal within seconds of oil pressure loss.

Kingstream supplies replacement main bearing sets, connecting rod bearing sets, and thrust bearings for Xinchai 490/4D27G3, 6102 series, and Dachai 498 diesel forklift engines. Every bearing set is verified for wall thickness and crush height before shipment.

Types:
• Main Bearing Set XC490-4D27G3 — Main bearing shells for Xinchai 490 and 4D27G3 diesel engines. The main bearings support the crankshaft in the engine block. One set covers all main journals
• Connecting Rod Bearing XC490-4D27 — Rod bearing shells for Xinchai 490 and 4D27 engines. Fit between the connecting rod big end and the crankshaft rod journal
• 6102 Main Bearing Set — Main bearing set for 6102 series diesel engines. Larger bearing dimensions for higher-displacement engines
• Dachai 498 Thrust Bearing — Crankshaft thrust bearing for Dachai 498 diesel engine (HELI CPCD30). Controls crankshaft end-play. Worn thrust bearing causes excessive crankshaft fore-aft movement
• STD Main Bearing Set / STD Rod Bearing Set — Standard-size universal bearing sets for diesel forklift engines. STD = standard journal size (not undersized for reground crankshafts)

When to Replace Engine Bearings:
• Low oil pressure at hot idle (below 15 psi) with normal oil level → Excessive bearing clearance allows pressurized oil to bleed out too fast. Replace bearings and measure crankshaft journals
• Knocking noise from the engine that increases with RPM, especially under load → Worn connecting rod bearings. The rod has excessive clearance at the crankshaft journal. Replace immediately — a spun bearing destroys the crankshaft
• Metal particles (copper-colored flakes) in the oil filter or on the magnetic drain plug → Bearing overlay is wearing through to the copper-lead layer. The bearing is near failure
• Crankshaft end-play exceeds specification when measured with a dial indicator → Worn thrust bearing. Excessive end-play causes clutch disengagement issues and uneven main bearing wear
• Engine being rebuilt after any lower-end failure (spun bearing, oil starvation, contamination) → Replace ALL bearings as a set. Never replace individual bearings — uneven wear patterns will cause the new bearing to fail prematurely

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Compatible: Xinchai 490/4D27, Dachai 498, 6102 series. Browse our engine parts catalog.