REMOVAL & INSTALLATION
See Figures 1 and 2
For the removal of the camshaft or balance shaft, the engine assembly will probably need to be removed from the vehicle.
- Disconnect the negative battery cable. Remove the engine and secure it to a workstand.
- Remove the flywheel-to-crankshaft bolts and remove the flywheel.
- Remove the intake manifold.
- Remove the lifter guide retainer.
- Unfasten the timing chain cover-to-engine bolts, then remove the cover.
- Remove the balancer shaft drive gear bolt.
- Remove the camshaft sprocket and timing chain.
- Remove the balance shaft retainer bolts, retainer and gear.
- Using a suitable slide hammer tool, pull the balance shaft from the front of the engine.
- Remove the balance shaft rear plug by driving it from the engine.
- Remove the balance shaft rear bearing using a suitable bearing removal and installer tool to press the rear bearing from the engine.
The balance shaft and both bearings are serviced as a complete package. You must use the proper tools when replacing the bearing and shaft.
- Inspect the balance shaft drive gear and the camshaft drive gear for nicks and burrs.
Install the balance shaft gear bearing, as follows:
- Dip the new bearing in clean engine oil.
- Using the balance shaft rear bearing installer tool, press the new rear bearing into the rear of the engine.
- Dip the front balance shaft into clean engine oil. Using the balance shaft installer tool, screw it into the balance shaft and install the shaft into the engine; remove the installer tool.
- Temporarily install the balance shaft bearing retainer and bolts. Install the balance shaft drive gear. Apply a suitable sealer to the bolt threads, then install the bolt. Tighten the bolts to 14 ft. lbs. (20 Nm), plus an additional 35° rotation for 1987-92 vehicles. For 1993-99 vehicles, tighten the bolt to 16 ft. lbs. (22 Nm), plus an additional 70° rotation.
- Install the rear cup plug.
- Measure the balance shaft radial play at both the front and the rear. The end-play should be 0.00-0.008 in. (0-0.203mm).
Measure the balance shaft radial play at both the front and the rear and compare with the following specifications:
- Front: 0-0.0011 (0-0.028mm).
- Rear: 0.0005-0.0047 in. (0.127-0.119mm).
- Turn the camshaft so, with the camshaft sprocket temporarily installed, the timing mark is straight down.
- With the camshaft sprocket and the camshaft gear removed, turn the balance shaft so that the timing mark on the gear points straight down.
- Install the camshaft gear. Align the marks on the balance shaft gear and the camshaft gear by turning the balance shaft.
- Turn the crankshaft so that the No. 1 piston is at Top Dead Center (TDC).
- Install the timing chain and camshaft sprocket.
- Measure the gear lash at four places, every 1 / 4 turn. The lash should be 0.002-0.005 in. (0.050-0.127mm).
- Install the balance shaft front bearing retainer. Install the retainer bolts and tighten them to 22-26 ft. lbs. (30-35 Nm).
- Install the front timing cover and the lifter guide retainer.
- Install the intake manifold.
- Install the flywheel assembly and tighten the bolts to the specifications given later in this section.
- Install the engine assembly and connect the negative battery cable. Start the engine and check for leaks.