OEM 2001 Jeep Wrangler Piston

2001 Jeep Wrangler Piston Parts and Q&A

• Q: How to Safely Remove and Replace a Piston in an Engine on 2001 Jeep Wrangler?

  A: Before you take out and put back the piston, you should remove the engine cylinder head cover, rocker arms, bridges, pivots, push rods and engine cylinder head, in that order. Take out the piston and use a guide to place one in position at the bottom of the stroke; with a ridge reamer, eliminate the ridge from the top of the cylinder wall and pick up the cuttings with a suitable cloth. Lift up the car and drain the engine oil before you remove the oil pan. Afterward, get rid of the bearing caps and inserts for the connecting rods and rotate each following letter to see the picture beside it. Watch that the bolts do not contact the journals or walls while the vehicle is about 2 feet from the floor and use bits of rubber hose for protection right under them. An assistant should move the piston and connecting rod assemblies into the top of the cylinders. Soak the piston and connecting rod group in a proper cleaning solution, inspect the connecting rod journal for too much wear, tapering and marks and check the connecting rod itself for signs of bend or twisting. Before you fit the piston into the cylinder bore, make sure it has the correct taper and elliptical shape and check for signs of score or scrape marks in the piston skirts and for cracks or wear in the ring lands. After cleaning the cylinder bores well, lightly apply clean engine oil to them with a clean, lint-free cloth during installation. Replace the piston rings if necessary and smear all sides of the pistons and the rings with oil approved for your engine. After installing piston ring compressors, fasten the connecting rod/piston together and insert each assembly so the arrow on the piston points to the front of the engine. Leave the vehicle raised and carefully add each insert onto its matching journal to get the required clearance, using the proper size inserts found in the table. Next to the flange, a paint mark on the crankshaft cheek or counterweight will have a color that indicates which size of rod journal is installed. Upper and lower bearing parts of different sizes might be used together and joining a standard insert with one slightly smaller can bring the clearance down by half the undersize. You should not mix connecting rod and bearing cap sets because each is marked with the cylinder number next to the oil squirt hole facing the camshaft part of the block. Prepare the rods with the connecting rod caps and inserts, making sure the little oil squirt holes are pointing at the camshaft and the arrows on the pistons are at the front. Install the oil pan and seal it in place with the gasket, set the vehicle back on the ground and fit the engine cylinder head, push rods, rocker arms, bridges, pivots and cover, before sliding in the oil.