This listing is for one shim that goes between the Ambac Model M-50 or American Bosch PSU diesel injection pump and the engine block on your Onan Diesel powered MEP002a or MEP003a generator set or on another Onan DJB, DJC, DJE, or DJF Diesel Engine. The shims are used to set the amount of lash between the drive gear on the camshaft and the face gear on the injection pump. If your shims are damaged, you should replace with the same combination that was originally on the unit. There are 4 thicknesses.

Note we have encountered more than one engine where an entire shim kit (all four shims, .002", .003", .004" and .005") were installed. However, when checked with a depth micrometer I found that only one or two shims were needed. Because of this, you should measure your engine block with a depth micrometer to determine how many shims you actually need. Too much or to little lash will damage the gears.

Choose your shim thickness below.