Measuring Connecting Rod Bearing Clearance - Using J 43690/J 43690-100

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J 43690 and 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 Checking Tool (J 43690) Components

Courtesy of GENERAL MOTORS CORP.

J 43690 Rod Bearing 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)

J 43690-100 Rod Bearing Checking 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 2: Identifying Rod Bearing Checking Tool - Adapter (J 43690-100) Components

Courtesy of GENERAL MOTORS CORP.

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

Rotate the crankshaft until the journal/connecting rod to be measured is in the 12 o'clock position.
Remove a bearing cap and bolts (1).
Remove the bearing half (2).
Insert a piece of paper card stock onto the crankshaft journal.
Install the bearing half (2) and cap and bolts (1). Refer to Fastener Tightening Specifications .

Fig 3: Installing Bearing Half, Cap & Bolts
Courtesy of GENERAL MOTORS CORP.
Install the following:
1. 6.1. J 43690-2 (5)
2. 6.2. J 43690-3 (4)
3. 6.3. J 43690-101 (2)
4. 6.4. 280310 (3)
5. 6.5. J 43690-5 (1)
Fig 4: Installing J 43690-2, J 43690-3, J 43690-101, J 43690-5 & 280310
Courtesy of GENERAL MOTORS CORP.
Install the swivel base (1) and dial indicator (2).
Adjust per the manufacturers instructions and measure the connecting rod bearing clearance.
A connecting rod with a clearance in excess of 0.076 mm (0.003 in) is considered excessive. Service components as required.

Fig 5: Installing Swivel Base & Dial Indicator
Courtesy of GENERAL MOTORS CORP.