How to Connect Rod Bearings

Replace connecting rod worn bearings.

The rod bearings mount between the connecting rods and crankshaft rod journals. They provide a space for oil lubrication and protection against premature crankshaft and bearing wear. However, when worn out, new bearing inserts will need to be installed. For this procedure, you should have the crankshaft, pistons, rings and related components installed on the engine block. In addition, if you need to check the connecting rod bearings' oil clearance before final installation, consult your vehicle service manual. An oil clearance check can be done in conjunction with this procedure.

Things You'll Need

• Engine stand
• Lint-free cloth
• New engine oil
• 2 pieces of rubber hose
• Hammer with a wood handle
• Engine assembly lube
• Torque wrench

Instructions

1. Mount and secure the engine block on an engine stand or holding fixture of some kind, if possible. This will make your job safer and easier.

2. Clean the bearing surfaces of the connecting rod and cap of piston number one (the one closest to the front of the engine) with a lint-free piece of cloth.

3. Align and mount the new upper bearing half on the bearing surface of the connecting rod of piston number one. Make sure the tab on the new bearing aligns with the recess on the bearing surface. Install the upper bearing with your hands only to avoid scratching or damaging the rod or bearing surface.

4. Align and mount the other new bearing half on the connecting rod cap, making sure the tab on the new bearing aligns with the recess on the cap bearing surface. Install the bearing by hand only.

5. Apply a light coat of new engine oil to the cylinder wall of piston number one.

6. Slide a piece of rubber hose on each of the two rod-cap mounting studs of the connecting rod on piston number one.

7. Push the piston into the cylinder to bring the connecting rod bearing surface close to the crankshaft journal. Use the wood handle of a hammer to push in the piston.

8. Apply a coat of engine assembly lube to both halves of the bearing surfaces.

9. Slide the connecting rod on its corresponding journal on the crankshaft. Then remove the protective hoses from the rod mounting studs.

10. Mount the rod cap on the connecting rod studs and start the retaining nuts by hand.

11. Torque the nuts in three steps using a torque wrench. Consult the service manual for your particular vehicle for the correct torque.

12. Install the rest of the connecting rod bearings following Steps 2 through 11.

References

• The Haynes Ford Engine Overhaul Manual; Brian Styve and John H. Haynes; 1991
• Modern Automotive Technology; James E. Duffy; 2003