Connecting Rod Clearance Measurement Procedure - Using J 43690 and J 43690-100

The J 43690  and the J 43690-100  have been developed as a more accurate method to measure connecting rod bearing clearances. The instructions below provide an overview of tool set-up and usage. For more detailed information, refer to the tool instruction sheets as supplied by the tool manufacturer.

Fig 1: Identifying Rod Bearing Clearance Checking Tool

Courtesy of GENERAL MOTORS CORP.

J 43690 Rod Bearing Clearance Checking Tool

• J 43690-20 Swivel Base (1)
• J 43690-19 Dial Indicator (2)
• J 43690-2 Base (3)
• J 43690-5, -6 Handle (4)
• J 43690-10, -11 Foot (5)
• 280307 Screw (6)
• J 43690-1 Pivot Arm Assembly (7)
• J 43690-3, -7, -8 Screws (8)
• 280319 Screw (9)
• 280311 Screw (10)
• J 43690-17, -18 Adapter (11)
• 280310 Pin (12)

Fig 2: Identifying Rod Bearing Clearance Tool - Adapter Kit

Courtesy of GENERAL MOTORS CORP.

J 43690-100 Rod Bearing Clearance Tool - Adapter Kit

• J 43690-104 Spacer (1)
• J 43690-105 Retainer Plate (2)
• 505478 Bolt (3)
• 511341 Bolt (4)
• J 43690-106 Retainer Plate (5)
• J 43690-107 Cap (6)
• J 43690-102 Foot (7)
• J 43690-101 Pivot Arm Assembly (8)
• J 43690-103 Adapter (9)
• 505439 Adapter (10)

Fig 3: View Of Connecting Rod Cap
Courtesy of GENERAL MOTORS CORP.
1. Install the connecting rod end cap on its original connecting rod making sure the bearing lock tangs are aligned on the same side of the rod.
Fig 4: View Of Paired Connecting Rod Bearing Cap Notches
Courtesy of GENERAL MOTORS CORP.
2. When properly installed, the connecting rod bearing cap notches should be paired, as shown, on the crankpin.
Fig 5: View Of Connecting Rod Cap
Courtesy of GENERAL MOTORS CORP.
NOTE: Refer to Fastener Notice .
IMPORTANT: Reuse the old connecting rod bolts ONLY for measuring the connecting rod bearing clearance.
3. Lubricate connecting rod bolts with engine oil and install in the connecting rod.

   Tighten:  Tighten the connecting rod bolts to 30 N.m (22 lb ft).

4. Loosen the connecting rod bolts until the torque reading is zero.
5. Re-tighten the connecting rod bolts.
   1. First Pass

      Tighten:  Tighten the connecting rod bolts to 25 N.m (18 lb ft).

   2. Final Pass

      Tighten:  Tighten the connecting rod bolts an additional 110 degrees using the J 45059  .

Fig 6: View Of Lower Crankcase
Courtesy of GENERAL MOTORS CORP.
6. Align the lower crankcase with the dowel pins in the upper crankcase.
7. Install the lower crankcase onto the upper crankcase slowly until feeling a positive stop.
8. Inspect the upper-to-lower crankcase joint in order to make sure the lower crankcase is fully seated on the cylinder block.
Fig 7: View Of Oil Scraper Plate & Oil Manifold Plate
Courtesy of GENERAL MOTORS CORP.
9. In order to gain access for the J 43690  and the J 43690-100  remove the oil scraper plate from the old oil manifold plate, if fastened into place.
Fig 8: View Of Oil Manifold Plate
Courtesy of GENERAL MOTORS CORP.
10. Install the oil manifold plate.
Fig 9: View Of Oil Manifold Plate Bolts
Courtesy of GENERAL MOTORS CORP.
11. Install the oil manifold plate bolts.

    Tighten:  Tighten the oil manifold plate bolts to 10 N.m (89 lb in).

Fig 10: View Of Lower Crankcase Main Bearing Bolts
Courtesy of GENERAL MOTORS CORP.
12. Install the lower crankcase main bearing bolts.
Fig 11: View Of Lower Left Crankcase Perimeter Retaining Bolts
Courtesy of GENERAL MOTORS CORP.
13. Install the left side upper-to-lower crankcase perimeter bolts.
Fig 12: View Of Right Upper-To-Lower Crankcase Perimeter Bolts
Courtesy of GENERAL MOTORS CORP.
14. Install the right side upper-to-lower crankcase perimeter bolts.
Fig 13: Tightening Lower Crankcase Bolts
Courtesy of GENERAL MOTORS CORP.
15. Install the lower crankcase main bearing bolts.
    1. First Pass

       Tighten:  Tighten the lower crankcase main bearing bolts (1-20) to 20 N.m (15 lb ft) in the proper sequence.

    2. Final Pass

       Tighten:  Tighten the lower crankcase main bearing bolts (1-20) an additional 65 degrees in the proper sequence using the J 45059  .

Fig 14: Tightening Upper-To-Lower Crankcase Perimeter Bolts
Courtesy of GENERAL MOTORS CORP.
16. Tighten the upper-to-lower crankcase perimeter bolts (1-10).

    Tighten:  Tighten the upper-to-lower crankcase perimeter bolts (1-10) to 30 N.m (22 lb ft) in the proper sequence.

17. Using the J 39946  rotate the crankshaft until the crankshaft journal and the connecting rod to be measured is in the 12 o'clock position. See Special Tools .
IMPORTANT: The crankshaft must be secure with no movement or rotation in order to obtain an accurate reading.
18. Remove the crankshaft main bolts required to install the retainer plate J 43690-105.
19. Install the J 43690-105 retainer plate and crankshaft main bolts. Refer to Lower Crankcase Installation  for tightening specifications.
IMPORTANT: Do not allow the J 43690-105 retainer plate screw to contact the reluctor ring.
20. Tighten the J 43690-105 retainer plate screw until snug in order to secure the crankshaft movement.
21. Install the foot and bolt to the J 43690-101 pivot arm assembly. Tighten the bolt until snug.
22. Install the J 43690-101 pivot arm assembly onto the connecting rod and tighten the screw securely.
23. Install the base and bolt to the oil pan rail.
24. Align the center of the base with the screw of the J 43690-101 pivot arm assembly. Tighten the bolt until snug.
25. Align the link of the J 43690-101 pivot arm assembly on a plane equal to that of the connecting rod beam.
26. Insert the pin to the base and J 43690-101 pivot arm assembly.
27. Select the adapter as required and install to the swivel base. Tighten until snug.
28. Install the swivel base to the oil pan rail.
IMPORTANT: The clamp of the swivel base and the shaft of the indicator should be free of oil or other debris. A loose or improperly clamped indicator may indicate incorrect readings.
29. Install the indicator to the swivel base. Tighten the clamp of the base until snug.
IMPORTANT: The tip of the indicator should be positioned above and NOT in contact with the end of the connecting rod.
30. Adjust the swivel base as required and position the indicator tip slightly above the connecting rod cap. Lock the swivel base in position by rotating the locking lever.
31. Rotate the fine adjustment knobs on the dial indicator end of the swivel base in order to position the tip of the indicator in contact with the connecting rod.
32. Lightly actuate the handle of the pivot arm assembly, multiple times in both directions, to ensure the oil film is removed from the connecting rod.
33. Load the handle in the forward position and zero the dial indicator. Load the handle multiple times in both directions and record the readings.
34. Refer to Fastener Tightening Specifications for proper clearances.
35. Remove the J 43690-105 retainer plate.
36. Install the crankshaft main bolts. Refer to Lower Crankcase Installation  for tightening specifications.
37. Reposition the tools and repeat steps 2-21 for all other connecting rods.
38. If clearances do not meet specifications, replace components as required.
39. Remove the lower crankcase when the procedure is complete.