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

WARNING: This page is about a different car, the 2019 GMC Savana 3500, 2019 GMC Savana 2500, 2019 Chevrolet Express 3500, and 2019 Chevrolet Express 2500. However, it is still accessible from the selected car via links, so may be relevant.

J 43690 tool and J 43690-100 kit 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 supplied by the tool manufacturer.

Courtesy of GENERAL MOTORS COMPANY

J 43690 tool

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

Courtesy of GENERAL MOTORS COMPANY

J 43690 Rod Bearing Checking Tool

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)

Courtesy of GENERAL MOTORS COMPANY

NOTE:
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 Specifications .
Courtesy of GENERAL MOTORS COMPANY

Install the following:
1. J 43690-2 (5)
2. J 43690-3 (4)
3. J 43690-101 (2)
4. 280310 (3)
5. J 43690-5 (1)
Courtesy of GENERAL MOTORS COMPANY

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.