ISM, ISMe, and QSM11 – 001-054   Piston and Connecting Rod Assembly

CAUTION  Do not use emery cloth or sandpaper to remove carbon from the cylinder liners. Aluminum oxide or silicon particles from emery cloth or sandpaper can cause serious engine damage. Do not use any abrasives in the ring travel area. The cylinder liner can be damaged.

Use a fine fibrous abrasive pad such as Scotch-Brite™ 7448, Part Number 3823258, or equivalent, and solvent to remove the carbon.

Rotate the crankshaft to position the rod caps at bottom dead center for removal.

Loosen the connecting rod capscrews.

NOTE: Do not remove the capscrews from the rods at this time.

Use a rubber hammer to hit the connecting rod capscrews to loosen the caps from the dowel rings.

Remove the connecting rod capscrews.

Remove the rod caps.

Remove the lower rod bearings.

Mark the cylinder number and the letter “L” (lower) in the flat surface of the bearing tangs.

NOTE: Some M Series engines were built without drilled connecting rods and without bearings with an oil hole in the upper bearing shell. Beginning in the fall of 1995, all M series engines are built with drilled connecting rods and bearings with an oil hole in the upper bearing shell.

Install two connecting rod guide pins, Part Number 3376038.

Use a “t-handle” piston pusher to push the rod away from the crankshaft.

Push the rod until the piston rings are outside of the top of the cylinder liner.

Use both hands to remove the piston and connecting rod assembly.

If parts are reused, the piston and connecting rod assemblies must be installed in the same cylinder number from which they were removed, to make sure of proper fit of worn mating surfaces,

Mark and attach a tag showing the cylinder number from which the piston and connecting rod assembly was removed.

Place the rod and piston assemblies in a container to protect them from damage.

A unique number (not cylinder number) is stamped on the connecting rod and matching cap. When the rods and caps are installed in the engine, the numbers on the rods and caps must match and be installed on the same side of the engine.

Remove the upper rod bearing.

Mark the cylinder number and the letter “U” (upper) in the flat surface of the bearing tang.