Tuesday, April 10, 2012

Timing Chain removal on Silverado and Sierra?

The complete timing chain removal for Chevrolet Silverado and GMC Sierra.

The details for 4.3L Engine car model.

The procedure is as follows:----

Removal & Installation

4.3L Engine
  1. Drain the cooling system.
  2. Remove or disconnect the following:

    Negative battery cable
    Timing chain cover and gaskets
  3. Rotate the crankshaft until the timing marks on the camshaft and crankshaft sprockets are in proper alignment. This will put no. 4 cylinder at TDC.
  4. Unsnap the timing chain tensioner shoe from the pin.
  5. Remove or disconnect the following: 
    The camshaft sprocket (located by a dowel) is lightly pressed onto the camshaft and should come off easily. The chain comes off with the camshaft sprocket.

    Camshaft sprocket-to-camshaft nut and/or bolts
    Camshaft sprocket (along with the timing chain), if the sprocket is difficult to remove, use a plastic mallet to bump the sprocket from the camshaft. 

    Fig. Timing mark alignment for timing chain removal and installation-4.3L engines
  6. If necessary use J-5825-A, or equivalent, crankshaft sprocket removal tool to free the timing sprocket from the crankshaft.
  7. Remove the crankshaft balancer key.
  8. If necessary, remove the timing chain tensioner bracket bolt and bracket.
To install:
  1. Inspect the timing chain and the timing sprockets for wear or damage, replace the damaged parts as necessary.
  2. Clean the gasket mounting surfaces of all remaining traces of old gasket.
    During installation, coat the thrust surfaces lightly with Molykote® or equivalent pre-lube.
  3. If necessary, install the timing chain tensioner bracket and bolt and tighten to 106 inch lbs. (12 Nm).
  4. Install the key into the crankshaft keyway. The crankshaft balancer key should be parallel to the crankshaft or with a slight incline.
  5. Install or connect the following:

    Crankshaft sprocket onto the crankshaft, use tool J-5590, crankshaft sprocket installation tool, and a hammer, without disturbing the position of the engine.
    Timing chain, arrange the camshaft sprocket in such a way that the timing marks will align between the shaft centers and the camshaft locating dowel will enter the dowel hole in the cam sprocket.
    Cam sprocket, with the chain mounted under it in position on the front of the camshaft. Torque the camshaft sprocket-to-camshaft retainer bolts to 106 inch lbs. (12 Nm) on 5.0L and 5.7L, or 18 ft. lbs. (25 Nm) on 4.3L.
  6. Install the timing chain tensioner shoe onto the bracket and position the top of the shoe under the tab at the top of the bracket.
  7. With the timing chain installed, turn the crankshaft 2 complete revolutions, then check to make certain that the timing marks are in correct alignment between the shaft centers.

    Timing chain cover with a new seal
    Negative battery cable
  8. Fill the cooling system with the proper type and quantity of antifreeze.

These details will help.


Car repair guide?

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