Crankshaft 320/A3238 JCB Dieselmax 444, genuine

Genuine JCB crankshaft 320/A3238 is another shaft version listed for the Dieselmax 444 engine family. There is no product photo yet; the card gives SB as the engine code. If the stamped number on the old shaft is readable, include it in your request.

The crankshaft turns the reciprocating motion of the pistons into rotation and passes torque to the flywheel, front pulley and timing gears. In the four-cylinder Dieselmax the shaft runs on five main journals, with the connecting 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. A reground shaft takes undersize bearings, while a new shaft is standard size and runs on standard main and big-end bearings. The front gear and pulley are checked at the same time.

Specifications

Compatibility

320/A3238 is a different number from the 320/03336 shaft; the choice between them is made by the engine serial number. For comparison see the genuine crankshaft 320/03336. Other JCB parts are in JCB Dieselmax engine.

Fitting

When a new shaft goes in, the main and big-end bearings, the crankshaft thrust washers and the front and rear seals are renewed; end float is measured and the main bearing bolts are torqued to JCB figures. Oil passages are cleaned before assembly and oil pressure is checked on first start-up.