No. 1 main bearing shells, standard 02/802459 JCB, aftermarket

No. 1 main bearing shells, standard 02/802459 is an aftermarket part for the JCB machines.

Bearing shells are the plain bearings in which the crankshaft or connecting rod turns on a pressurised oil film; they are a steel back with an anti-friction lining. Worn shells cause low oil pressure, knocking from the bottom end and at worst a spun bearing. Size follows the journal: standard for an unground shaft, undersize for a reground one. The number of shells in a pack depends on the part number, so state the quantity the engine needs when ordering. The colour or number code on the shells can mark different size groups within the same engine, so compare the marks on the old shells with the new ones. Shells are always replaced in pairs (upper and lower). The shells are supplied new.

Specifications

Compatibility

Other parts are in Perkins engine.

Fitting

Measure the journals, lay the shells in clean, dry housings with their tangs in the notches and coat them with assembly lube. Tighten the cap bolts to the service manual torques and check oil pressure on first start. Do not fit new shells until the cause of low oil pressure has been found.