Setting Camshaft Timing. Cadillac Concours 1996

For 1990-2009 cars

#### Tools Required

• | J 39946 Crankshaft Rotation Socket

• | J 39411 Flywheel Holder

Setting the camshaft timing is necessary whenever the camshaft drive system has been disturbed such that the relationship between any chain and sprocket has been lost. Even when only one sprocket is involved the following procedure should be observed since one crankshaft rotation will not provide conditions where correct timing can be confirmed.

The camshafts and crankshaft events are correctly timed when the relationships shown exist. The following procedure explains how to establish this condition. Correct timing exists when the crank sprocket and the intermediate shaft sprocket have their timing marks aligned and all four camshaft drive pins are perpendicular (90 degrees) to the cylinder head surface.

1. Remove the following components for access:

• | The left camshaft cover. Refer toCamshaft Cover Replacement (Left) .

• | The right camshaft cover. Refer toCamshaft Cover Replacement (Right) .

• | The front cover. Refer toEngine Front Cover Replacement .

• | The three chain tensioners (the tensioners may be in their installed positions but must be fully retracted).

• | The oil pump. Refer toOil Pump Replacement .

2. The primary and secondary chain guides should be reinstalled if previously removed.
3. Rotate the crankshaft until the sprocket drive key is at approximately the 1 o'clock position. UseJ 39946 to rotate the crankshaft.
4. Install the crankshaft and the intermediate shaft sprockets to the primary drive chain with their timing marks adjacent to each other.
5. Install the crank and intermediate sprockets over their respective shafts.
6. Rotate the crankshaft as necessary to engage the crankshaft key in the sprocket without changing the relationship of the timing marks to each other. UseJ 39946 to rotate the crankshaft.

Notice: Use the correct fastener in the correct location. Replacement fasteners must be the correct part number for that application. Fasteners requiring replacement or fasteners requiring the use of thread locking compound or sealant are identified in the service procedure. Do not use paints, lubricants, or corrosion inhibitors on fasteners or fastener joint surfaces unless specified. These coatings affect fastener torque and joint clamping force and may damage the fastener. Use the correct tightening sequence and specifications when installing fasteners in order to avoid damage to parts and systems.

7. Install the intermediate sprocket retainer bolt.

Tighten
Tighten the bolt to 60 N·m (44 lb ft).

8. Install the primary chain tensioner or release the tensioner shoe.

Tighten
Tighten the tensioner mounting bolts to 25 N·m (18 lb ft).

9. Install flywheel holderJ 39411 to lock crankshaft in this position. If the engine is on a stand, an alternate method should be devised.
10. Route the secondary drive chain for the LH cylinder head over the inner row of intermediate shaft teeth.

Important: The RE camshaft sprocket must contain the camshaft position sensor pick-up.

11. Route the secondary drive chain over the chain guide and install the exhaust camshaft sprocket to the chain such that the camshaft drive pin engages the sprocket notch marked LE (left head exhaust). There should be no slack in the lower section of the chain and the camshaft drive pin must be perpendicular to the cylinder head face.
12. Install the intake camshaft sprocket into the chain so that the sprocket notch marked LI (left head intake) engages the camshaft drive pin while the pin remains perpendicular to the cylinder head face. A hex is cast into the camshafts behind the lobes for cylinder -1 (or -2, LH) so that an open end wrench may be used to provide minor repositioning of the camshafts.
13. Loosely install the exhaust camshaft sprocket retainer bolt.
14. Loosely install the intake camshaft sprocket retainer bolt.
15. Install the chain tensioner or release the tension on the shoe.

Tighten

• | Tighten the tensioner mounting bolts to 25 N·m (18 lb ft).

• | Tighten the camshaft sprocket bolts to 120 N·m (90 lb ft).

Important: The RE camshaft sprocket must contain the camshaft position sensor pick-up.

16. Route the secondary drive chain for right side cylinder head over outer row of intermediate shaft teeth and repeat steps 11 through 15 for right side camshafts. Right side camshaft sprockets are identified as RI (right intake) and RE (right exhaust). In addition the RE sprocket must contain the camshaft position sensor pickup.