Idler shaft-timing drive. Camshafts-in vehicle

Idler shaft-timing drive

REMOVAL

(1) Remove the timing chain and sprockets. Refer to procedure in this section.

NOTE: To remove the idler shaft, it is necessary to tap threads into the shaft to install the removal tool.

(2) Using a 12 mm X 1.75 tap, cut threads in the idler shaft center bore (Fig. 89).

Fig. 89 Tapping Idler Shaft For Special Tool 8517

1 - IDLER SHAFT

2 - TAP 12mm X 1.75

(3) Cover the radiator core with a suitable cover.

CAUTION: Use care when removing idler shaft, DO NOT strike the radiator cooling fins with the slide hammer.

(4) Using Special Tool 8517 Slide Hammer, remove the idler shaft (Fig. 90).

Fig. 90 Removing Idler Shaft

1 - IDLER SHAFT

2 - SPECIAL TOOL 8517

INSTALLATION

(1) Thoroughly clean the idler shaft bore.

(2) Position the idler shaft in the bore.

NOTE: The two lubrication holes in the idler shaft do not require any special alignment.

NOTE: Before using the retaining bolt to install the idler shaft, coat the threads and the pilot on the idler shaft with clean engine oil.

(3) Using the primary idler sprocket retaining bolt and washer, carefully draw the idler shaft into the bore until fully seated.

(4) Coat the idler shaft with clean engine oil and install the timing chains and sprockets. Refer to procedure in this section.

Camshafts-in vehicle

LEFT CAMSHAFT

REMOVAL

CAUTION: When the timing chain is removed and the cylinder heads are still installed, DO NOT forcefully rotate the camshafts or crankshaft independently of each other. Severe valve and/or piston damage can occur.

CAUTION: When removing the cam sprocket, timing chains or camshaft, Failure to use Special Tool 8350 will result in hydraulic tensioner ratchet over extension, requiring timing chain cover removal to reset the tensioner ratchet.

(1) Remove cylinder head cover. Refer to Cylinder Head Cover in this section.

(2) Set engine to TDC cylinder #1, camshaft sprocket V8 marks at the 12 o'clock position.

(3) Mark one link on the secondary timing chain on both sides of the V8 mark on the camshaft sprocket to aid in installation.

CAUTION: Do not hold or pry on the camshaft target wheel (Located on the right side camshaft sprocket) for any reason, Severe damage will occur to the target wheel resulting in a vehicle no start condition.

(4) Loosen but DO NOT remove the camshaft sprocket retaining bolt. Leave the bolt snug against the sprocket.

NOTE: The timing chain tensioners must be secured prior to removing the camshaft sprockets.

Failure to secure tensioners will allow the tensioners to extend, requiring timing chain cover removal in order to reset tensioners.

CAUTION: Do not force wedge past the narrowest point between the chain strands. Damage to the tensioners may occur.

(5) Position Special Tool 8350 timing chain wedge between the timing chain strands, tap the tool to securely wedge the timing chain against the tensioner arm and guide (Fig. 91).

(6) Hold the camshaft with adjustable pliers while removing the camshaft sprocket bolt and sprocket (Fig. 92).

(7) Using the pliers, gently allow the camshaft to rotate 15 clockwise until the camshaft is in the neutral position (no valve load).

(8) Starting at the outside working inward, loosen the camshaft bearing cap retaining bolts 1/2 turn at a time. Repeat until all load is off the bearing caps.

CAUTION: DO NOT STAMP OR STRIKE THE CAMSHAFT BEARING CAPS. SEVERE DAMAGE WILL OCCUR TO THE BEARING CAPS.

NOTE: When the camshaft is removed the rocker arms may slide downward, mark the rocker arms before removing camshaft.

Fig. 91 Securing Timing Chain Tensioners Using Timing Chain Wedge

1 - LEFT CYLINDER HEAD

2 - RIGHT CYLINDER HEAD

3 - SPECIAL TOOL 8350 WEDGE

4 - SPECIAL TOOL 8350 WEDGE

Fig. 92 Camshaft Sprocket and Chain

1 - CAMSHAFT SPROCKET AND CHAIN

2 - ADJUSTABLE PLIERS

3 - CAMSHAFT

(9) Remove the camshaft bearing caps and the camshaft.

INSTALLATION

(1) Lubricate camshaft journals with clean engine oil.

NOTE: Position the left side camshaft so that the camshaft sprocket dowel is near the 1 o'clock position, This will place the camshaft at the neutral position easing the installation of the camshaft bearing caps.

(2) Position the camshaft into the cylinder head.

(3) Install the camshaft bearing caps, hand tighten the retaining bolts.

(4) Working in 1⁄2 turn increments, tighten the bearing cap retaining bolts starting with the middle cap working outward (Fig. 93).

(5) Torque the camshaft bearing cap retaining bolts to 11 N*m (100 in. lbs.).

(6) Position the camshaft drive gear into the timing chain aligning the V8 mark between the two marked chain links (Two links marked during removal) (Fig. 94).

(7) Using the adjustable pliers, rotate the camshaft until the camshaft sprocket dowel is aligned with the slot in the camshaft sprocket. Install the sprocket onto the camshaft (Fig. 95).

Fig. 93 Camshaft Bearing Caps Tightening Sequence

CAUTION: Remove excess oil from camshaft sprocket bolt. Failure to do so can cause bolt overtorque resulting in bolt failure.

(8) Remove excess oil from bolt, then install the camshaft sprocket retaining bolt and hand tighten.

(9) Remove Special Tool 8350 timing chain wedge (Fig. 91).

(10) Using Special Tool 6958 spanner wrench with adapter pins 8346 (Fig. 96), torque the camshaft sprocket retaining bolt to 122 N*m (90 ft. lbs.).

(11) Install the cylinder head cover.

RIGHT CAMSHAFT

REMOVAL

CAUTION: When the timing chain is removed and the cylinder heads are still installed, DO NOT forcefully rotate the camshafts or crankshaft independently of each other. Severe valve and/or piston damage can occur.

CAUTION: When removing the cam sprocket, timing chains or camshaft, Failure to use special tool 8350 will result in hydraulic tensioner ratchet over extension, Requiring timing chain cover removal to re-set the tensioner ratchet.

(1) Remove the cylinder head covers. Refer to Cylinder Head Cover in this section.

Fig. 94 Timing Chain to Sprocket Alignment

1 - LEFT CYLINDER HEAD

2 - RIGHT CYLINDER HEAD

Fig. 95 Camshaft Sprocket Installation

1 - ADJUSTABLE PLIERS

2 - CAMSHAFT DOWEL

(2) Set engine to TDC cylinder #1, camshaft sprocket V8 marks at the 12 o'clock position.

(3) Mark one link on the secondary timing chain on both sides of the V8 mark on the camshaft sprocket to aid in installation.

CAUTION: Do not hold or pry on the camshaft target wheel for any reason, Severe damage will occur to the target wheel. A damaged target wheel could cause a vehicle no start condition. (4) Loosen but DO NOT remove the camshaft sprocket retaining bolt. Leave bolt snug against sprocket.

NOTE: The timing chain tensioners must be secured prior to removing the camshaft sprockets.

Failure to secure tensioners will allow the tensioners to extend, requiring timing chain cover removal in order to reset tensioners. CAUTION: Do not force wedge past the narrowest point between the chain strands. Damage to the tensioners may occur. (5) Position Special Tool 8350 timing chain wedge between the timing chain strands. Tap the tool to securely wedge the timing chain against the tensioner arm and guide (Fig. 97).

(6) Remove the camshaft position sensor (Fig. 98).

Fig. 96 Tightening Left Side Cam Sprocket Retaining Bolt

1 - TORQUE WRENCH

2 - CAMSHAFT SPROCKET

3 - LEFT CYLINDER HEAD

4 - SPECIAL TOOL 6958 SPANNER WITH ADAPTER PINS 8346

(7) Hold the camshaft with adjustable pliers while removing the camshaft sprocket bolt and sprocket (Fig. 99).

(8) Using the pliers, gently allow the camshaft to rotate 45 counter-clockwise until the camshaft is in the neutral position (no valve load).

(9) Starting at the outside working inward, loosen the camshaft bearing cap retaining bolts 1/2 turn at a time. Repeat until all load is off the bearing caps.

CAUTION: DO NOT STAMP OR STRIKE THE CAMSHAFT BEARING CAPS. SEVERE DAMAGE WILL OCCUR TO THE BEARING CAPS.

NOTE: When the camshaft is removed the rocker arms may slide downward, mark the rocker arms before removing camshaft. (10) Remove the camshaft bearing caps and the camshaft.

Fig. 97 Securing Timing Chain Tensioners Using Timing Chain Wedge

1 - LEFT CYLINDER HEAD

2 - RIGHT CYLINDER HEAD

3 - SPECIAL TOOL 8350 WEDGE

4 - SPECIAL TOOL 8350 WEDGE

Fig. 98 Camshaft Position Sensor

1 - CRANKSHAFT POSITION SENSOR

2 - CYLINDER HEAD COVER

3 - CAMSHAFT POSITION SENSOR

4 - RIGHT SIDE CYLINDER BLOCK

Fig. 99 Camshaft Sprocket and Chain

1 - ADJUSTABLE PLIERS

2 - SPROCKET BOLT

3 - CAMSHAFT SPROCKET AND CHAIN

4 - CAMSHAFT

INSTALLATION

(1) Lubricate camshaft journals with clean engine oil.

NOTE: Position the right side camshaft so that the camshaft sprocket dowel is near the 10 o'clock position, This will place the camshaft at the neutral position easing the installation of the camshaft bearing caps. (2) Position the camshaft into the cylinder head.

(3) Install the camshaft bearing caps, hand tighten the retaining bolts.

(4) Working in 1/2 turn increments, tighten the bearing cap retaining bolts starting with the middle cap working outward (Fig. 100).

Fig. 100 Camshaft Bearing Caps Tightening Sequence

(5) Torque the camshaft bearing cap retaining bolts to 11 N*m (100 in. lbs.).

(6) Position the camshaft drive gear into the timing chain aligning the V8 mark between the two marked chain links (Two links marked during removal) (Fig. 101).

(7) Using the adjustable pliers, rotate the camshaft until the camshaft sprocket dowel is aligned with the slot in the camshaft sprocket. Install the sprocket onto the camshaft (Fig. 102).

CAUTION: Remove excess oil from camshaft sprocket bolt. Failure to do so can cause bolt overtorque resulting in bolt failure. (8) Remove excess oil from camshaft sprocket bolt, then install the camshaft sprocket retaining bolt and hand tighten.

(9) Remove timing chain wedge special tool 8350 (Fig. 97).

(10) Using Special Tool 6958 spanner wrench with adapter pins 8346 (Fig. 103), torque the camshaft sprocket retaining bolt to 122 N*m (90 ft. lbs.).

(11) Install the camshaft position sensor (Fig. 98).

(12) Install the cylinder head cover.