Connecting Rod Bearing Clearance Measurement Procedure - Using EN-43690-A

The EN-43690-A  checking tool has 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: Rod Bearing Clearance Checking Tool Kit

Courtesy of GENERAL MOTORS COMPANY

EN 43690-A  checking tool

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

Fig 2: Rod Bearing Clearance Tool - Adapter Kit

Courtesy of GENERAL MOTORS COMPANY

EN 43690-A  adapter kit

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

Fig 3: Connecting Rod Bearing And Cap
Courtesy of GENERAL MOTORS COMPANY
NOTE:

Connecting rod bearings that have been run in an engine should NEVER be reused.

Before final assembly it is important to check the clearance of the new connecting rod bearings.

1. Install the connecting rod bearing into the connecting rod cap.
NOTE:

The connecting rod is non-directional therefore the connecting rod bearing lock tangs can face inboard or outboard.

2. Install the connecting rod end cap on its original connecting rod and ensure the bearing lock tangs are aligned on the same side of the rod.
CAUTION:

Refer to Fastener Caution .

CAUTION:

Do not lubricate the NEW connecting rod bolts. The NEW bolts have a pre-applied graphite lubricant. Applying lubricant to the connecting rod bolts will effect the clamp load when the connecting rod bolts are torqued. Improper clamp load can lead to component failure and extensive engine damage.

NOTE:

Reuse the old connecting rod bolts ONLY for measuring the connecting rod bearing clearance.

3. Install the connecting rod bolts into the connecting rod cap.
4. Tighten the connecting rod bolts.
   1. First Pass

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

   2. Final Pass

      Tighten the connecting rod bolts an additional 110 degrees using the EN 45059  meter.

5. Rotate the crankshaft until the crankshaft journal and the connecting rod to be measured is in the 12 o'clock position.
NOTE:

The crankshaft must be secure with no movement or rotation in order to obtain an accurate reading.

6. Remove the crankshaft main bolts required to install the retainer plate EN 43690-105.
NOTE:

Do not allow the EN 43690-105 retainer plate screw to contact the reluctor ring.

7. Install the EN 43690-105 and crankshaft main bolts.
8. Loosen the connecting rod bolts until the torque reading is zero.
9. Re-tighten the connecting rod bolts.
   1. First Pass

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

   2. Final Pass

      Tighten the connecting rod bolts an additional 110 degrees using the EN 45059  meter.

10. During and after installation, ensure each piston is positioned properly in the correct cylinder. The locating arrow on the top of each piston must be pointing toward the front of the engine.
11. Repeat these procedures for the remaining piston/connecting rod assemblies using the EN-48589  socket in order to rotate the crankshaft.