Aurora V8-4.0L VIN C (1996)
Camshaft: Technical Service Bulletins
Camshaft Timing - Revised Setting Procedure
File In Section: 6 - Engine
Bulletin No.: 83-61-29
Date: September, 1998
SERVICE MANUAL UPDATE
Subject:
Section 6 - Revised Setting Camshaft Timing Procedure for On Vehicle Service
Models:
1996-97 Cadillac DeVille, Eldorado, Seville
1996-97 Oldsmobile Aurora
with 4.0L, 4.6L Engine (VINs C, Y, 9 - RPOs L47, LD8, L37)
This bulletin is being issued to revise the setting camshaft timing procedure in Section 6 - Engine Mechanical - Repair Instructions of the Service
Manual.
Procedure
Setting Camshaft Timing
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.
Tools Required:
^
J 39946 Crankshaft Rotation Socket
^
J 39411 Flywheel Holder
1.
Remove the following components for access:
^
The left camshaft cover. Refer to Valve Rocker Arm Cover Replacement (left).
^
The right camshaft cover. Refer to Valve Rocker Arm Cover Replacement (right).
^
The front cover. Refer to Engine Front Cover Replacement.
^
The three chain tensioners (the tensioners may be in their installed positions, but must be fully retracted).
^
The oil pump. Refer to Oil Pump Cover and Gear Set Removal.
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. Use J 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 sprocket without changing the relationship of the timing marks to each other.
Use J 39946 to rotate the crankshaft.
Notice:
Refer to Fastener Notice in Cautions and Notices.
