Main bearing set 320/09335 JCB Dieselmax standard, OEM

For the JCB Dieselmax 444 and 448 engines: main bearing set 320/09335, standard, an OEM part. The card also lists 320/03243.

The crankshaft is carried on five main journals, with a pair of shells working on each. A tang or lock on the back stops the shell turning in its housing; the lock position differs between engine versions, so the set is chosen to suit the engine. Poor oil, lubrication faults and long periods of overload wear the bearings quickly. Replacement usually goes together with measuring the crankshaft and renewing the big-end bearings. The shell size is marked on the back of each shell, showing standard or the undersize value.

Specifications

Compatibility

The part is listed for JCB 3CX and 4CX backhoe loaders. The set is for standard main bearings with side locks; for engines with the lock in the middle of the upper shell choose the main bearing set 320/09202. The catalogue also has the aftermarket version, genuine version (set) and genuine version (shell 320/03243) of this part. Other parts are in JCB Dieselmax engine.

Fitting

Before fitting, wipe the housings and journals with a lint-free cloth: a single speck of dust can mark a bearing. Fit the caps by their numbers and the right way round, and tighten the bolts in stages. Priming the oil system before the first start protects the bearings from a dry start.