Pistons, Piston Pins, Connecting Rods and Bearings

REMOVAL

NOTE: Although it is easier and cleaner to work on an engine which has been removed, pistons and connecting rods can be removed with the engine still in the car (after the cylinder head and oil pan have been removed). Engine removal is required, however, if the crankshaft will also be removed.

All parts must be retained in order — including the bearings and caps. Mark the caps for installation in the same position in both directions, if they are not already marked. Note that on all engines except those used in the 1983–89 626/MX-6 and the 1986–89 323, thrust bearings are at the rear main. This main bearing cap must be removed with a puller. The 1983–87 2.0L engines have them on the center main, and the 1.6L turbo and non-turbo engines have them on the No. 4 main. Be careful not to lose or mix up the thrust washers. On the 1988–89 626 and MX-6, crankshaft thrust is taken up by the center main bearing. On these engines, the thrust washers are integral with the bearing.

NOTE: When removing the crankshaft, use a stand that permits the engine to be inverted. Remove the engine (or engine/transaxle assembly) as described earlier in this section. If applicable, separate the transaxle from the engine. After removing the flywheel/flexplate, detach the oil pump from the front of the engine. (Refer to these procedures elsewhere in this section.) Invert the engine, then remove the main bearing caps, bearings and crankshaft, as described later in this section.

1. If applicable, remove the engine from the vehicle, as previously described in this section, and mount it on a suitable workstand. Otherwise, remove the cylinder head(s) and oil pan, also as previously described.
2. Note the position of each piston, connecting rod and connecting rod cap before removal, to ensure reinstallation in the same location. Check the tops of the pistons and the sides of the connecting rods for identifying marks. If no identifying numbers or marks are present, use a number punch set and stamp in the numbers yourself.
3. Rotate the crankshaft until the piston to be removed is at the bottom of the cylinder. Inspect the upper area of the cylinder wall for a ridge above the top piston ring. If cylinder wall wear has created a noticeable ridge, it should be removed with a ridge reamer, to prevent damage to the rings during piston removal. For further information on ridge removal, refer to the procedure later in this section.

   WARNING
   Be very careful if you are unfamiliar with operating a ridge reamer. It is very easy to remove more cylinder bore material than intended, possibly requiring a cylinder overbore and piston replacement that could have been avoided.

4. Loosen the connecting rod nuts until they are flush with the ends of the rod bolts. Use a hammer and brass drift or piece of wood to lightly tap on the nuts/bolts until the connecting rod cap comes free of the connecting rod. Remove the nuts, rod cap and lower bearing insert.
5. Slip a length of snug fitting rubber hose over each rod bolt, to prevent the bolt threads from damaging the crankshaft during removal.
6. Using a hammer handle or piece of wood or plastic, tap the rod and piston upward in the bore until the piston rings clear the cylinder block. Remove the piston and connecting rod assembly from the top of the cylinder bore.
7. If applicable, repeat Steps 3–6 for the other pistons.