Engine Piston - Improved
89mitsubishi10SUBJECT:
IMPROVED V-6 PISTON
NO. TSB-89-11-008
DATE November, 1989
MODEL 1987, 1988 Sigma V-6, Montero
PURPOSE
Improved left-hand pistons have been made available for the V-6 engine. When repairing vehicles with manufacture dates between October 1987 to March 1989, installation of the new pistons may reduce the possibility of cold engine piston slap.
PART INFORMATION
Piston application can be identified by the cylinder number designations. Even numbered cylinders piston number:
MD152563. (New part number) Odd numbered cylinders piston number:
MD119671 (Existing part number)
It is not necessary to replace all pistons when repairing an engine. Replace only those pistons that are to be installed in even numbered cylinders.
PISTON IDENTIFICATION
New pistons have "L" stamped on the piston top.
NOTE: THESE PISTONS MUST BE INSTALLED IN THE EVEN NUMBERED CYLINDERS!
Engines with early equipped pistons have a "R" and "L" stamped on the piston top.
NOTE: THESE ORIGINAL PISTONS CAN ONLY BE INSTALLED IN THE ODD NUMBERED CYLINDERS.
PISTON ORIENTATION
Odd numbered cylinders - 1, 3, 5 Install the piston onto the connecting rod with the "R" on the same side of the rod as the front mark on the connecting rod. Install the piston into the engine block so that the "R" is facing the front of the engine (crankshaft pulley side).
Even numbered cylinders - 2, 4, 6 Install the piston onto the connecting rod with the "L" on the same side of the rod as the front mark on the connecting rod. Install the piston into the engine block so that the "L" is facing the front of the engine (crankshaft pulley side).
CAUTION: At no time should there be a piston installed in an Even numbered cylinder that has a "R" AND "L" stamped in its top.