Below are directions:
Fig. Fig. 1: Remove the timing cover bolts
Fig. Fig. 2: Remove the timing cover from the engine
- Drain the cooling system.
- Drain the oil and lower the oil pan.
- If equipped, remove the Crankshaft Position Sensor (CKP).
- Remove the crankshaft pulley and damper. Remove the water pump.
- Unfasten the retainers holding the timing case cover to the block and remove the cover and gaskets.
- Use a suitable tool to pry the old seal out of the front face of the cover.
- Install the new seal so that the open end is toward the inside of the cover.
Coat the lip of the new seal with oil prior to installation.
- Check that the timing chain oil slinger is in place against the crankshaft sprocket.
- Apply sealer to the front cover as shown in the accompanying illustration. Install the cover carefully onto the locating dowels.
- Tighten the attaching screws to 124 inch lbs. (14 Nm) on the 4.3L and 100 inch lbs. (11 Nm) on the 5.0L and 5.7L.
- Install the remaining components and fill the engine with oil and coolant. Road test the truck.
Fig. Fig. 3: Using a seal puller, remove the old seal from the front cover
Fig. Fig. 4: Installing the new seal in the front cover
Fig. Fig. 5: Oil pan front seal modification
Fig. Fig. 6: Front seal installed
Fig. Fig. 7: Sealer application
Fig. Fig. 8: Cutting the seal
Fig. Fig. 9: Guiding the cover into place. Make sure the seal remains undisturbed
- Remove the timing cover. This will allow access to the timing chain.
- Crank the engine until the timing marks on both sprockets are nearest each other and in line between the shaft centers.
Fig. Fig. 1: Crank the engine until the timing marks on both sprockets are in line
- Take out the bolts that hold the camshaft gear to the camshaft. This gear is a light press fit on the camshaft and will come off easily. It is located by a dowel. The chain comes off with the camshaft gear.
Fig. Fig. 2: Remove the camshaft gear retaining bolts
Fig. Fig. 3: Remove the camshaft gear and timing chain
A gear puller will be required to remove the crankshaft gear.
- Without disturbing the position of the engine, mount the new crankshaft gear on the shaft, and mount the chain over the camshaft gear. Arrange the camshaft gear in such a way that the timing marks will line up between the shaft centers and the camshaft locating dowel will enter the dowel hole in the cam sprocket.
- Place the cam sprocket, with its chain mounted over it, in position on the front of the truck and pull up with the three bolts that hold it to the camshaft.
- After the gears are in place, turn the engine two full revolutions to make certain that the timing marks are in correct alignment between the shaft centers. Tighten the camshaft sprocket bolts (and nut on the 4.3L) to 21 ft. lbs. (28 Nm) on 1988-95 models.
When installing the crankshaft position sensor you must use install a new oil ring seal onto the sensor.
- Install the crankshaft position sensor reluctor ring (if equipped), onto the crankshaft until it is firmly seated against the crankshaft sprocket.
- Install the front cover, torsional damper, water pump and the radiator.
Fig. Fig. 4: A gear puller will be required to remove the crankshaft gear
Fig. Fig. 5: Timing mark alignment-4.3L, 5.0L, 5.7L and 7.4L engines