Rocker cover (SB) 320/07634 JCB Dieselmax, aftermarket

Rocker cover (SB) 320/07634 is an aftermarket part for the JCB Dieselmax 444 engines.

The rocker cover closes the top of the cylinder head, keeps dust and dirt out of the rocker gear and holds the oil in. It may carry the oil filler and the breather connection. A cracked or warped cover leaks even with a new gasket. Cover shape and fixing points differ between engine versions. Baffles inside the cover can help separate oil droplets from the gases going to the breather. The cover is aluminium or pressed steel, and one bent by a knock does not sit evenly on its gasket. When replacing it, check the filler cap, breather connection and bolt isolators too. The valve clearances can be checked before the cover goes back on. The cover is supplied new, with the gasket and isolators chosen separately. Check the cover shape against the part number. The gasket face must be flat.

Specifications

Compatibility

According to sources, 320/07634 is the rocker cover assembly; it supersedes the older numbers 320/07630, 320/07600 and 333/E3504R and is listed for JCB Dieselmax engines and the generators fitted with them. Other parts are in JCB Dieselmax engine.

Fitting

Fit the cover with a new gasket and tighten the bolts evenly from the centre outwards, since overtightening warps it. Check for leaks after starting.