Camshaft and gear 320/03685 JCB Dieselmax SD, genuine

Camshaft and gear 320/03685 is a genuine JCB part for the JCB Dieselmax 444 (SD) engine.

The camshaft opens and closes the valves through its lobes and is driven from the crankshaft through its gear. Worn lobes reduce valve lift: power drops, the engine runs unevenly and a tapping comes from the rocker side. Shaft and gear are assembled with the timing marks that set the valve timing. The camshaft gear meshes with the crankshaft gear and turns the camshaft at half crankshaft speed. A chipped or worn tooth can upset the timing, so the gear is checked together with the shaft. Because different camshaft versions are used for different fuel systems within one engine family, give the engine serial number when ordering. When the shaft is replaced, a clean oil pump and clean passages matter so that the new lobes are oiled from the first hours. A key or dowel fixes the gear position on the shaft.

Specifications

Compatibility

The part is listed for JCB 3CX and 4CX backhoe loaders. The shaft is for Dieselmax engines with the SD build code; for other codes see the camshaft 320/03681. The catalogue also has the aftermarket version of this part. Other parts are in JCB Dieselmax engine.

Fitting

Before the old shaft comes out, check and note the gear marks. Slide the new shaft into the block without damaging the bearings; tighten the gear bolt to JCB torque. Renew worn followers together with the shaft. After assembly, set the valve clearances to JCB figures.