Information on New Special Service Tool EN-47945 forLK5, L52 or LL8 Engine Allowing Stationary Hydraulic Lash Adjusters and End Pivot Rockers to Be Removed without Camshaft Removal

On Vehicle Valve Spring Compressor EN-47945

This bulletin is being published to inform technicians that General Motors has released a new special service tool. The new On Vehicle Valve Spring Compressor (EN-47945) will assist in the removal and replacement, if required, of the Stationary Hydraulic Lash Adjusters (SHLA) and End Pivot Rockers without removing the camshafts. The following information will assist technicians in the removal and replacement of SHLA and End Pivot Rockers:

1. Rotate the engine crankshaft until the affected cylinder's valve is fully open (cam lobe fully depressing the spring).

Important: Engine design and packaging do not allow all cylinder locations to use both fasteners for holding the tool to the cylinder head. One fastener is sufficient in these locations.

2. Install the EN-47945 on the engine cylinder head using either one or two of the supplied fasteners installed in the coil fastener hole to hold the tool.

Notice:  Do not over rotate the engine with the tool installed. It is possible to damage the valves if they contact the piston. Rotate the engine just enough to come back to the base circle of the cam. After repairs, rotate the engine slowly in the opposite direction just enough to fully depress the spring prior to tool removal.

3. Rotate the engine clockwise just enough to ensure that the cam is on the base circle (spring will stay compressed by the tool). This allows the lash adjuster and rocker to be removed and replaced.
4. When the new components are in place, rotate the engine counterclockwise just enough that the cam lobe fully depresses the spring again.
5. Remove the tool and repeat as required.

Any GM dealer that needs to order the Special Service Tool EN-47945 (On-Vehicle Valve Spring Compressor) can contact SPX Kent-Moore at 1-800-345-2233.