Forklift Connecting rod

Forklift Connecting Rod: Forged Steel Con Rods for Weichai Hyundai Nissan Isuzu Xinchai MTZ Diesel Engines

The connecting rod — also called con rod — is the forged steel link between the piston and the crankshaft that converts the reciprocating linear force of combustion into the rotational torque that drives the forklift. It is one of the most highly stressed components in any internal combustion engine: at 2,600 RPM under full load, each rod cycles between maximum tension (pulling the piston downward on the intake stroke) and maximum compression load (resisting peak combustion pressures exceeding 1,000 psi) over 40 times per second, accumulating billions of alternating stress cycles over the engine’s lifetime. A failed connecting rod — whether from a spun big-end bearing, fatigue fracture at the rod bolt threads, or hydrolock bending — typically punches through the engine block wall within 2-3 revolutions of failure, destroying the cylinder block, crankshaft, neighboring rods, pistons, and often the cylinder head in an irreparable chain reaction. The most common failure points are the connecting rod bolts (torque-to-yield fasteners that stretch permanently during the first installation and lose clamping force if reused), the big-end bore (out-of-round crushes the bearing shell asymmetrically), and the transition radius between the rod beam and the big-end (stress concentration from sharp tool marks or forging defects).

Kingstream supplies replacement connecting rods for Weichai WP12 (Sinotruk/Shacman heavy trucks), Hyundai/Kia D4CB 2.5L diesel (K2500/Sorento), Russian MTZ D-144/T-16/T-25/T-40 tractor engines, Nissan K25 diesel (forklifts and engineering machinery), XinChai 4D35G (Chinese forklift and truck engines), and Isuzu 4JB1 (2.8L diesel for forklifts, NPR/NKR trucks, and industrial equipment from 1984-2009). Every connecting rod is inspected for big-end bore roundness, small-end bushing fit, center-to-center length, and bolt thread condition before shipment.

Types by Engine:
• Weichai WP12 (612630020017) — Connecting rod assembly for Weichai WP12 heavy-duty diesel engine in Sinotruk and Shacman trucks. Large-displacement 12L engine connecting rod designed for sustained full-load operation
• Hyundai/Kia D4CB 2.5L (235104A400) — 4X connecting rod set for Hyundai D4CB 2.5L diesel engine in K2500 truck and Sorento SUV. Industrial diesel variant used in forklift applications
• MTZ D-144 (37M-1004100) — OEM con rod assembly for Russian MTZ D-144, T-16, T-25, and T-40 tractor and stationary industrial diesel engines. Forged steel with bushed small end
• Nissan K25 (12100-FY500) — HRX brand OEM connecting rod for Nissan K25 2.5L diesel engine in forklifts and engineering machinery. ISO9001 certified, 10kg, 6-month warranty
• XinChai 4D35G (4D35G-ROD) — XinChai OEM connecting rod for 4D35G diesel engine in forklifts and light trucks. 1kg, 3-month warranty with free replacement parts and online technical support
• Isuzu 4JB1 (8-94329-692-0 / 8943296920) — Shunjun brand connecting rod for Isuzu 4JB1 2.8L diesel engine (1984-2009). Cr40 chromium-alloy forged steel, 1.3kg, 1-year warranty

When to Replace Connecting Rods:
• Loud knocking noise from the bottom of the engine that increases with RPM and does not change when individual injectors are disabled → Spun connecting rod bearing. The bearing has welded to the crankshaft journal and the rod big-end bore is scored. Replace rod, bearing, and inspect crankshaft
• Engine hydrolocked (water, coolant, or fuel entered a cylinder) and now has reduced compression on that cylinder → The connecting rod is bent. A bent rod changes piston-to-head clearance and compression ratio. Replace all rods on that bank
• Connecting rod bolt failure during engine disassembly — bolt threads are stripped, bolt is stretched (measures longer than specification), or bolt head is deformed → The rod bolt has been over-torqued or reused. Replace bolts with ALL rods — if one bolt failed, others may be near failure
• Metal particles (steel-colored, magnetic) in the oil filter that are not bearing material → Rod bolt or rod beam material is being shed. Immediate inspection required. Replace all rods showing surface distress
• Visible crack at the transition radius between rod beam and big-end — detected by magnetic particle inspection → Fatigue crack will propagate to complete fracture. Replace rod immediately
• Engine rebuild after any lower-end bearing failure (spun bearing, oil starvation) → Replace ALL connecting rods as a set. Individual rod replacement creates weight imbalance and uneven wear

OEM Cross-Reference:

Don’t see your engine? Send your engine model and con rod OEM number →

Compatible: Weichai WP12, Hyundai D4CB, MTZ D-144, Nissan K25, Xinchai 4D35G, Isuzu 4JB1. Browse our engine parts catalog.