Crankshaft 320/A3103 JCB Dieselmax, genuine

Crankshaft 320/A3103 is a genuine JCB part for the JCB Dieselmax 444 engine.

The crankshaft turns the reciprocating motion of the pistons into rotation and passes torque to the flywheel, front pulley and gear train. In a four-cylinder engine it runs on five main journals, with the rods on four crankpins. Scored or oval journals, a spun bearing, low oil pressure and knocking under load call for regrinding or replacement. A cracked or bent shaft can only be replaced. Oil passages drilled through the crankshaft carry oil from the main journals to the crankpins; swarf or dirt in them soon ruins the bearings. If the repair followed a spun bearing, the block oil passages, oil cooler and oil pump are also cleaned or replaced, or metal particles will reach the new shaft and bearings. The front end carries the pulley and gear, the rear end the flywheel flange. The shaft is forged steel with hardened journals. The shaft is balanced. The crankshaft is supplied new. Check the journal sizes before assembly.

Specifications

Compatibility

The part is listed for JCB 3CX and 4CX backhoe loaders. Other parts are in JCB Dieselmax engine.

Fitting

Coat the journals with assembly lube; once the shaft is in place, turn it by hand to check it rotates freely. Line up the gears by their timing marks. Blow the oil passages through with compressed air before fitting the shaft.