Overview - Pistons And Connecting Rod

Fig 1: Exploded View Of Piston And Connecting Rod

Courtesy of VOLKSWAGEN GROUP OF AMERICA, INC.

1. Connecting Rod Bolts
   • 45 Nm +90°
   • Replace after removing.
   • Use the old bolt for the radial clearance measurement
   • Lubricate the threads and contact surface.
2. Connecting Rod Bearing Cap
   • Note the installation position
   • Due to the separation procedure (cracking) of the connecting rod, the connecting rod bearing cap only fits in one position and only to the corresponding connecting rod.
   • Mark the cylinder to which it belongs -A-
   • Installation position: the marks -B- face the belt pulley side
   • Disconnect the new connecting rod. Refer to NEW CONNECTING ROD, SEPARATING .
3. Bearing Shells
   • Installation position. Refer to Fig 2.
   • Do not interchange used bearing shells (mark them)
   • Lubricate before installing
   • New axial play: 0.10 to 0.35 mm, wear limit: 0.40 mm
   • Measure radial clearance with Plastigauge^® ; new: 0.02 to 0.06 mm, wear limit: 0.09 mm. Do not turn crankshaft during the radial clearance measurement
4. Relief Valve
   • 27 Nm
5. Oil Spray Jet
   • For piston cooling
6. Circlip
   • Replace after removing.
7. Piston Pin
   • Coat with oil before installing
8. Piston
   • Removing and installing. Refer to PISTONS, REMOVING AND INSTALLING .
   • Mark the installation position and cylinder allocation
   • Arrow on piston crown points toward belt pulley side
   • Check piston and cylinder bore. Refer to PISTON AND CYLINDER BORE, CHECKING .
9. Compression rings
   • Use piston ring pliers (commercially available) for removing and installing
   • Offset gaps by 120°
   • Installed Position: "TOP" "R" mark must face up toward piston crown
   • Ring Gap/Groove Clearance, Checking. Refer to PISTON AND CYLINDER BORE, CHECKING .
10. Oil Scraping Ring
    • Two-part
    • Install offset gaps by 120° to the neighboring compression ring
    • The "TOP" or "R" marking must face toward the piston crown.
    • Checking the piston ring gap. Refer to PISTON AND CYLINDER BORE, CHECKING .
    • Side clearance cannot be measured.
11. Connecting Rod
    • Always replace as a set
    • Mark the cylinder to which it belongs -A-
    • Installation position: the marks -B- face the belt pulley side
    • Disconnect the new connecting rod. Refer to NEW CONNECTING ROD, SEPARATING .
    • Radial play, measuring. Refer to CONNECTING RODS, CHECKING RADIAL CLEARANCE .

Bearing Shell Installation Position 

Fig 2: Bearing Shell Installed Position

Courtesy of VOLKSWAGEN GROUP OF AMERICA, INC.

-- Place the bearing shells centrally into connecting rod and connecting rod bearing cap.

The dimension -a- must be the same at left and right.