Piston and Connecting Rod Assemble

Special Tools 

EN-49941  Remover / Installer Piston Retainer Ring

For equivalent regional tools, refer to Special Tools .

Fig 1: Connecting Rod, Piston And Piston Pin
Courtesy of GENERAL MOTORS COMPANY
NOTE:

Lubricate the piston pin with clean engine oil.

1. Install the connecting rod (3) and the piston pin (2) to the piston (1).
2. Install the piston and connecting rod assembly to a bench vise. Use aluminium braces.
Fig 2: Pushing Piston Pin Retainer Down With Thumb
Courtesy of GENERAL MOTORS COMPANY
WARNING:

Use extreme care when removing snap rings. Always wear adequate eye protection in order to avoid personal injury.

WARNING:

Use care when removing or installing the piston retainer ring. Ensure the EN-49941 remover/installer is installed properly onto the retainer ring and that hands and fingers are kept clear from the front of the tool. Otherwise, bodily injury may occur.

NOTE:

Notch (2) on right side.

3. Place the piston pin retainer in the piston pin retainer groove so that the ring gap lays on the notch (2).
4. Push the piston pin retainer down with the thumb in the shown position (1) and hold.
NOTE:

The EN-49941  installer should be applied in a perpendicular position to the piston pin retainer.

5. Apply the EN-49941  installer (4) to the piston pin retainer in the position shown (3) and push in direction of the arrow while pushing down with the thumb.
Fig 3: Pushing Piston Pin Retainer Down
Courtesy of GENERAL MOTORS COMPANY
NOTE:

Push the piston pin retainer down in the position shown (2).

6. Move the EN-49941  installer (1) carefully to the position shown while pushing in direction of the arrow until the piston pin retainer engages in the piston pin retainer groove.
7. Push down the piston ring retainer to get a proper seat in the groove.
Fig 4: Pushing Piston Pin Retainer Down With Thumb
Courtesy of GENERAL MOTORS COMPANY
NOTE:

Notch (4) on left side. EN-49941  installer should be used with left hand.

8. Place the piston pin retainer in the piston pin retainer groove so that the ring gap lays on the notch (4).
9. Push the piston pin retainer down with the thumb in the position shown (1) and hold.
NOTE:

The EN-49941  installer should be applied in a perpendicular position to the piston pin retainer.

10. Apply the EN-49941  installer (3) to the piston pin retainer in the position shown (2) and push in direction of the arrow while pushing down with the thumb.
Fig 5: Pushing Piston Pin Retainer Down
Courtesy of GENERAL MOTORS COMPANY
NOTE:

Push the piston pin retainer down in the position shown (1).

11. Move the EN-49941  installer (2) carefully to the position shown while pushing in direction of the arrow until the piston pin retainer engages in the piston pin retainer groove.
12. Push down the piston ring retainer to get a proper seat in the groove.
13. Remove the piston and connecting rod assembly from the bench vise.
Fig 6: Using Piston Ring Pliers
Courtesy of GENERAL MOTORS COMPANY
14. Install the piston rings. Use piston ring pliers (1).
Fig 7: Upper Compression Ring, Lower Compression Ring, Oil Rings And Oil Ring Spacer
Courtesy of GENERAL MOTORS COMPANY
NOTE:

Mind the TOP marking on the piston rings.

15. The piston rings must be ordered as followed:
    • Upper compression ring (1)
    • Lower compression ring (2)
    • Piston oil ring with spacer (3), (4)
Fig 8: Oil Ring Joints, Lower Compression Ring Joint, Upper Compression Ring Joint And Oil Ring Spacer Joint
Courtesy of GENERAL MOTORS COMPANY
16. The piston ring joints must be positioned 90 degrees to each other.
    • Upper compression ring joint (2)
    • Lower compression ring joint (5)
    • Oil ring joint, upper part (1)
    • Oil ring joint, lower part (4)
    • Oil ring spacer joint (3)