Main bearing set 02/202911 Perkins RG standard, aftermarket, option 1

Main bearing set 02/202911, standard is an aftermarket part for the Perkins 1104 (RG) engine. The card also lists U5MB0033, U5MB0018, T427334, 353-7423.

Main bearings are the plain bearings in which the crankshaft runs in the block on a pressurised oil film. The set holds the upper and lower shells for one engine; the upper shells carry oil holes and grooves. Worn main bearings cause low oil pressure, knocking from the bottom of the engine and, at worst, a spun bearing. The size follows the crankshaft: standard for a shaft that has not been reground, undersize for a reground one. 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 machines fitted with these engines. In the Perkins catalogue this set is listed as U5MB0033 and U5MB0018 for 1104 series engines. The catalogue also has the aftermarket version and genuine version of this part. Other parts are in Perkins engine.

Fitting

When the new bearings go in, clean the housings, keep the backs of the shells dry and oil the running surfaces with engine oil. Check the crankshaft end float together with the thrust washers. Change the engine oil and filter after assembly; the oil pump and passages must be clean.