Tools Required

J 24086-C  Piston Pin Remover/Installer Set. See Special Tools .

Fig 1: View Of J 24086-920 & J 24086-10
Courtesy of GENERAL MOTORS CORP.
IMPORTANT:
• Disassembly of the piston, press-fit design piston pin, and connecting rod may create scoring or damage to the piston pin and piston pin bore. If the piston, pin, and connecting rod have been disassembled, replace the components as an assembly.
• If reusing the piston and connecting rod assembly, install the assembly to the original cylinder and corresponding crankshaft journal.
• The assembly procedure, as shown, is to be used for diagnostic purposes only.
1. Install fork insert J 24086-920 into J 24086-10  . See Special Tools .
Fig 2: View Of Connecting Rod Positioning Tab, Flat Flange & Mark On Top Of Piston
Courtesy of GENERAL MOTORS CORP.
CAUTION: Avoid contact with HOT components. Wear safety glasses and protective gloves to avoid personal injury.
NOTE: Applying excessive heat to the connecting rod may damage or distort the rod. Rod temperature SHOULD NOT exceed 315°C (600°F). At this temperature the end of the connecting rod will turn a straw color upon visual inspection.
2. Use a torch and apply MILD heat to the pin end of the connecting rod. Mild heating of the connecting rod will ease in piston and pin assembly.
3. Identify the positioning tab (1) or flat flange (3) of the connecting rod. When properly assembled, the positioning tab or flat flange of the rod and the mark (2) on the top of the piston should both be facing the front of the engine.
Fig 3: View Of Piston, Connecting Rod & J 24086-16A
Courtesy of GENERAL MOTORS CORP.
4. Assemble the piston, the connecting rod, and the J 24086-16A.
Fig 4: Adjusting J 24086-9 To G-4
Courtesy of GENERAL MOTORS CORP.
5. Adjust the J 24086-9 to I 8.
Fig 5: Inserting J 24086-9
Courtesy of GENERAL MOTORS CORP.
6. Install the piston, connecting rod, piston pin, and J 24086-16A to the J 24086-10  . See Special Tools .
Fig 6: View Of Piston, Pin & Connecting Rod Proper Assembly
Courtesy of GENERAL MOTORS CORP.
NOTE: After the installer hub bottoms on the support assembly, do not exceed 35 000 kPa (5,000 psi) pressure, this could cause damage to the tool.
7. Insert J 24086-9  through J 24086-10  and to the piston pin. See Special Tools .
8. Press J 24086-9  until the installer bottoms on the J 24086-10  . See Special Tools .
9. Inspect the piston (1), pin (3), and connecting rod (2) for proper assembly.

   When properly installed, the piston pin (3) should be centered in the connecting rod (2).

Fig 7: View Of Upper & Lower Compression Rings & Marks
Courtesy of GENERAL MOTORS CORP.
10. Identify the compression and oil control rings for proper installation. The upper compression ring can be identified by a paint mark (3) located 180 degrees from the end gap. The lower compression ring can be identified by a paint mark (3) located 90 degrees from the end gap. Both rings should be installed with the orientation marks (1, 2) facing the top of the piston.
Fig 8: Installing Piston Rings
Courtesy of GENERAL MOTORS CORP.
IMPORTANT: When installing piston rings, use a ring expander plier type tool. Do not roll the rings into the grooves of the piston. Use caution and care to expand the rings only slightly larger than the outside diameter (OD) of the piston.
11. Using piston ring pliers, install the piston rings onto the piston.
12. Position the oil control ring end gaps a minimum of 25 mm (1.0 in) from each other.
13. Position the compression ring end gaps 180 degrees opposite each other.
Fig 9: View Of Piston & Connecting Rod Components
Courtesy of GENERAL MOTORS CORP.
14. Install the connecting rod bearings (3) to the rod (2) and cap (4).