Balance Shaft: Installation
- Lubricate balance shaft bearings with engine oil. Install rear bearing with rolled edge facing inward, toward engine, and manufacturer's marking facing flywheel side of engine. Using Rear Bearing Installer (J-36995-1), install rear bearing. See Figure.
- Using Balance Shaft Installer (J-36996), install balance shaft. Temporarily install balance shaft retainer and bolts. Install balance shaft gear. Apply GM Threadlock (12345493) to gear bolt, and install bolt. Tighten gear bolt to specification. See TORQUE SPECIFICATIONS .
- Install balance shaft rear plug. Using dial indicator, measure balance shaft end play and radial clearance at front and rear of balance shaft. See Fig 1. Replace components if measurements are not within specification. See BALANCE SHAFT SPECIFICATIONS .
- Rotate camshaft so timing mark is downward when sprocket is installed. With camshaft sprocket and gear removed, rotate balance shaft so timing mark on gear is downward.
- Rotate balance shaft to align timing marks on camshaft gear and balance shaft gear, and install camshaft gear. See Figure. Rotate crankshaft so No. 1 piston is at TDC. Install timing chain and sprocket. Ensure timing marks are aligned. See Figure.
- Using dial indicator, measure gear lash at 4 places every 1/4 turn. Gear lash should be within specification. See BALANCE SHAFT SPECIFICATIONS .
- If measurements are within specification, tighten balance shaft retainer bolts to specification. See TORQUE SPECIFICATIONS . To complete installation, reverse removal procedure.
BALANCE SHAFT SPECIFICATIONS
| Application | In. (mm) | |
|---|---|---|
| Bearing Bore ID | ||
| Front | 2.0462-2.0472 (51.973-51.999) | |
| Rear | 1.950-1.952 (49.53-49.58) | |
| End Play | 0-.008 (0-.20) | |
| Gear Lash | .002-.005 (.05-.13) | |
| Radial Clearance | ||
| Front | 0-.0011 (0-.028) | |
| Rear | .0005-.0047 (.013-.119) | |