Connecting Rod: Service and Repair

Pistons and Connecting Rod Overview

• Lubricate all bearings and running surfaces.

• Oil injector jet for piston cooling, refer to => [ Oil Spray Jet For Piston Cooling ].






1 Bolts

• 60 Nm +90°

• Replace

• Lubricate the threads and contact surface

2 Connecting Rod Bearing Cap

• Mark for installation later

• Mark affiliation to cylinder with paint, refer to => [ Mark Connecting Rod ]

• Installation position of connecting rod pairs, refer to => [ Connecting Rod Installation Position ]

3 Bearing Shells

• Check that retaining tabs are secured

• Always replace if removed

• Over-sized bearings are available for reworked crankshaft connecting rod journals, refer to the Electronic Parts Catalog (ETKA)

4 Connecting Rod

• Only replace as a set

• Mark affiliation to cylinder with paint, refer to => [ Mark Connecting Rod ]

• Installation position of connecting rod pairs, refer to => [ Connecting Rod Installation Position ]

• Axial play for each new connecting rod pair: 0.20 to 0.27 mm

• Axial play wear limit: 0.30 mm

• Radial clearance, measuring, refer to => [ Connecting Rod Radial Clearance, Measuring ] Testing and Inspection

5 Piston Pin

• Removing and installing, refer to => [ Piston ] Piston

6 Locking Ring

• Replace

• Quantity: 2

7 Piston

• Removing and installing, refer to => [ Piston ] Piston

• Piston and cylinder bore, checking, refer to => [ Piston and Cylinder Bore, Checking ] Testing and Inspection

• Installed position, refer to => [ Piston Installed Position ]

8 Piston Rings

• Gap, measuring, refer to => [ Measuring the Piston Ring Gap ] Testing and Inspection

• Measuring side clearance, refer to => [ Measuring the Ring to Groove Clearance ] Testing and Inspection

• Use piston ring pliers (commercially available) for removing and installing

• Installed position: The "TOP" marking or side with writing faces the piston crown.

• Offset gaps by 120°.

Piston Installed Position






The coating on the piston crown could be destroyed.

• Mark the allocation to the cylinder on the piston crown with paint to install used pistons. Do not mark the piston crown with a punch, notch or similar object.

Installed position:

• The arrows on the piston heads point to the belt pulley side.

• Large valve recesses - 1 - point toward center of engine.

Mark Connecting Rod





• Only replace the connecting rods as a set.

- Mark the connecting rod and connector rod bearing caps to each other and to the cylinder - arrow - with paint for installation.

Connecting Rod Installation Position





• The molded tabs - arrows - on the beveled surfaces of connecting rod pairs "1 and 2", "3 and 4", "5 and 6" and "7 and 8" must face each other.

Oil Spray Jet For Piston Cooling





1. Oil spray jet

2. Insert bolts with locking compound and tighten to 9 Nm; Locking compound, refer to the Electronic Parts Catalog (ETKA).


• Do not bend the piston spray nozzles.

• Bend piston spray nozzles must be replaced.