Valve bridge 320/03647 JCB Dieselmax, aftermarket

For the JCB Dieselmax 444 engine: valve bridge 320/03647, an aftermarket part. The card also lists 320/03577.

Bridges sit on the valve stems, and their positions must be marked when the head comes off. A worn bridge shows up during valve adjustment: its two ends do not touch the valves at the same time. Bridges are also checked when valves are replaced. The Dieselmax has four valves per cylinder, so each cylinder uses one inlet and one exhaust bridge. The ends that touch the valves and the centre face the rocker presses on are hardened. Stretching oil change intervals speeds up wear of these faces. Each end of the bridge has a recess that locates on a valve stem. There are twice as many bridges as cylinders.

Specifications

Compatibility

The part is listed for JCB 3CX and 4CX backhoe loaders. The catalogue also has the genuine version of this part. Other parts are in JCB Dieselmax engine.

Fitting

Oil the contact faces and seat the bridge on the valve stems the right way round. Then set the valve clearance to JCB service figures. Mark the bridges by cylinder and by inlet or exhaust side before removing them. Adjust the valve clearance with the engine cold.