Piston Pin: Service and Repair

DISASSEMBLY
1. Remove connecting rod bearings from connecting rod and cap.
2. Remove piston rings using a suitable piston ring expander.
3. Mark piston to ensure assembly with same connecting rod and installation in same cylinders from which they were removed.





4. Using an arbor press and Piston Pin Remover and Replacer 303-S024 (T68P-6135-A), press piston pin from piston and connecting rod.

ASSEMBLY
Check the fit of a new piston in the cylinder bore before assembling piston and piston pin to connecting rod.

The piston pin bore of a connecting rod and diameter of piston pin must be within specification.

1. Apply light coat of Super Premium SAE 5W30 Motor Oil XO-5W30-QSP or equivalent meeting Ford specification WSS-M2C153-G to all parts.
2. Assemble piston to connecting rod.





3. Start piston pin in piston and connecting rod (this may require a very light tap with a mallet). Using an arbor press and Piston Pin Remover and Replacer 303-S024 (T68P-6135-A), press piston pin through piston until the piston pin is centered.

NOTE: Piston pin end of connecting rods must be heated to 250-400°C (482-752°F) directly prior to installation of piston pin to prevent piston pin and pin bore damage.

4. Check end gaps of all piston rings. It must be within specification. Follow instructions contained on piston ring package and install piston rings.
5. Check piston ring side clearance of compression rings with Feeler Gauge 303-D027 (D81L-4201-A) or equivalent by inserting it between piston ring and its lower land. This gauge should slide freely around entire piston ring circumference without binding. Any wear that occurs will form a step at inner portion of lower land. If lower lands have high steps, piston should be replaced.
6. Make sure connecting rod bearings and bearing bore in connecting rod and cap are clean. Foreign material under connecting rod bearings will distort connecting rod bearings and cause a failure. Install connecting rod bearings in connecting rod and cap with tangs fitting in slots provided.