General Information Buick LaCrosse II

Arrows and Symbols

This service manual uses various symbols in order to describe different service operations.

Scheme 1

Customer Concern Verification Sheets

The GM Customer Concern Verification Sheets have been designed to improve communications between the service customer and the technician. The more clearly the technician understands the concern and its symptoms, the more likely the concern will be fixed right the first time.

The GM-wide Customer Concern Verification Sheets are available in GM GlobalConnect. The Customer Concern Verification Sheets may be printed and reproduced locally.

Dealers

All U.S. Dealers participating in the Common Training Program can enroll through the Common Training System Website at https://www.gmtraining.com. Within the website, there are individual training paths that are designed to assist in planning the training needs for each individual. Technicians should advise their Service Manager of their training needs including course names and course numbers. Dealers who have questions about Common Training should contact the Common Training help desk at 1-888-748-2687. The help desk is available Monday through Friday, 8:00 am-8:00pm Eastern Standard Time, excluding holidays. For GM Access support, contact the GM Access Help Desk at 1-888-337-1010.

Fleets

GM Fleet customers with GM Warranty In-Shop agreements are able to participate in service technical training through Common Training/GM Service Technical College (STC).

Assistance for all GM fleet customers using GM STC products and services is provided on the Internet via www.gmtraining.com using the "Contact Us" button on the site and/or the Common Training Help Desk at 1-888-748-2687. To order GM STC Training Materials, please contact the GM Training Materials Headquarters at 1-800-393-4831.

Most GM STC course materials have associated charges.

To purchase authentic GM STC Training Materials, contact the GM Training Materials Headquarters at 1-800-393-4831.

Non-GM Dealer Technicians

Technicians training for non-GM dealers is available through ACDelco. This training is for ACDelco customers employed in the automotive or truck service industry.

ACDelco courses are available at all approved GM Training Centers. Availability and schedules can be obtained by calling 1-800-825-5886 or contact us via the web at www.acdelcotechconnect.com and select the training button. Clinics are also offered through ACDelco Warehouse Distributors. Contract your dealer directly for more information.

Scheme 2

The vehicle identification number (VIN) plate is the legal identifier of the vehicle. The VIN plate is located on the upper left corner of the instrument panel (I/P) and can be seen through the windshield from the outside of the vehicle

Vehicle, Engine and Transmission ID and VIN Location, Derivative and Usage

2.4L (LUK) Engine ID and VIN Derivative Location

Refer to Engine Identification (LAF, LEA, or LUK) .

3.6L (LFX) Engine ID and VIN Derivative Location

Refer to Engine Identification .

6T30/6T40/6T45 Transmission ID and VIN Derivative Location

Refer to Transmission Identification Information .

6T70/6T75 Transmission ID and VIN Derivative Location

Refer to Transmission Identification Information .

Scheme 3

Vehicle Certification, Tire Placard, Anti-Theft, and Service Parts ID Label

RPO Code List

RPO Code List

Metric Fasteners

This vehicle provides fastener dimensions using the metric system. Most metric fasteners are approximate in diameter to equivalent English fasteners. Make replacements using fasteners of the same nominal diameter, thread pitch, and strength.

A number marking identifies the OE metric fasteners except cross-recess head screws. The number also indicates the strength of the fastener material. A Posidrive® or Type 1A cross-recess identifies a metric cross-recess screw. For best results, use a Type 1A cross-recess screwdriver, or equivalent, in Posidrive® recess head screws.

GM Engineering Standards and North American Industries have adopted a portion of the ISO-defined standard metric fastener sizes. The purpose was to reduce the number of fastener sizes used while retaining the best thread qualities in each thread size. For example, the metric M6.0 X 1 screw, with nearly the same diameter and 25.4 threads per inch replaced the English 1/4-20 and 1/4-28 screws. The thread pitch is midway between the English coarse and fine thread pitches.

Scheme 4

The most commonly used metric fastener strength property classes are 9.8 and 10.9. The class identification is embossed on the head of each bolt. The English, inch strength classes range from grade 2 to grade 8. Radial lines are embossed on the head of each bolt in order to identify the strength class. The number of lines on the head of the bolt is 2 lines less than the actual grade. For example, a grade 8 bolt will have 6 radial lines on the bolt head. Some metric nuts are marked with a single digit strength identification number on the nut face.

The correct fasteners are available through GM SPO. Many metric fasteners available in the aftermarket parts channels are designed to metric standards of countries other than the United States, and may exhibit the following

1. Lower strength
2. No numbered head marking system
3. Wrong thread pitch

The metric fasteners on GM products are designed to new, international standards. The following are the common sizes and pitches, except for special applications

1. M6.0 X 1
2. M8 X 1.25
3. M10 X 1.5
4. M12 X 1.75
5. M14 X 2.00
6. M16 X 2.00

Prevailing Torque Fasteners

Prevailing torque fasteners create a thread interface between the fastener and the fastener counterpart in order to prevent the fastener from loosening.

All Metal Prevailing Torque Fasteners

These fasteners accomplish the thread interface by a designed distortion or deformation in the fastener.

Nylon Interface Prevailing Torque Fasteners

These fasteners accomplish the thread interface by the presence of a nylon material on the fastener threads.

Adhesive Coated Fasteners

These fasteners accomplish the thread interface by the presence of a thread-locking compound on the fastener threads. Refer to the appropriate repair procedure in order to determine if the fastener may be reused and the applicable thread-locking compound to apply to the fastener.

Scheme 5

A prevailing torque fastener may be reused ONLY if

1. The fastener and the fastener counterpart are clean and not damaged
2. There is no rust on the fastener
3. The fastener develops the specified minimum torque against its counterpart prior to the fastener seating

Metric Prevailing Torque Fastener Minimum Torque Development

English Prevailing Torque Fastener Minimum Torque Development

Thread Inserts

General Purpose Thread Repair Kits.

These kits are available commercially.

Repair Procedure

1. Determine the size, the pitch, and the depth of the damaged thread. If necessary, adjust the stop collars on the cutting tool and tap to the required depth.
2. Drill out the damaged threads. Clean out any chips.
3. Lubricate the tap with light engine oil. Tap the hole. Clean the threads.
4. Thread the thread insert onto the mandrel of the installer. Engage the tang of the insert onto the end of the mandrel.
5. Lubricate the insert with light engine oil, except when installing in aluminum and install the insert.
6. If the tang of the insert does not break off when backing out the installer, break the tang off with a drift.

Registered and Non-Registered Trademarks

Listed below are Registered Trademarks (®) or Non-Registered Trademarks (™) which may appear in this service manual.

Registered and Non-Registered Trademarks

Instrument Panel Compartment Door Lock Cylinder Coding

The internal lock cylinder only uses 4 of the 8 cut positions, 5-8. The tumbler positions are on both sides, are not self-retaining, and are not snap in.

1. Hold the instrument panel (I/P) cylinder assembly (4) so the side with the tumbler spring pocket located closest to the head of the cylinder is facing up. This side of the cylinder uses left tumbler.
2. Insert the tumbler spring (6) into each of the 2 spring pockets of the cylinder assembly. This side uses left tumblers.
3. The first tumbler (5) to be loaded (closest to the head of the cylinder) will be the fifth key cut position, which is the fifth number in the key code. Install the tumbler in the slot over the spring. Install the remaining tumblers following the key code and same process, pressing the tumblers in place until they are secure.
4. Rotate the cylinder assembly. Insert the tumbler spring (6) into each of the spring pockets of the cylinder assembly. This side uses right tumblers.
5. The first tumbler (5) to be loaded will be the sixth key cut position, the sixth number in the key code. Install the first tumbler in the slot over the spring. Install the remaining tumblers following the key code and same process, pressing the tumblers in place until they are secure.
6. Inspect for correct loading of the tumblers by inserting the key into the cylinder. All tumblers should drop flush with the lock cylinder body diameter.
7. Insert the sleeve (3) into the cylinder, the inner sleeve slot must be oriented to the head cylinder side. Rotate the sleeve until the slot match with the tab.
8. Insert the retainer spring (2) into the pocket and the tumbler retainer (1) over the spring. Make sure the tumbler retainer is properly seated and cannot pull out.
9. Lightly lubricate the outside surface in the tumbler area of the lock body and down the key slot using the provided grease. Insert and extract the key 5 times to lubricate the keyway.
10. When the key is removed, the lock should stay together.
11. Insert the key and function the lock 3 times to distribute the grease inside the sleeve.
12. Verify the key position for inserting the lock into the I/P compartment door.

Front Side Door Lock Cylinder Coding (Free Wheeling)

Special Tools

BO-49753 Assembly Tool

Scheme 6

The door lock cylinder uses 8 of the 8 cut positions. The tumbler positions are staggered from side to side, 4 on one side and 4 on the other, are not self-retaining, and are not snap in.

1. Hold the door lock cylinder (1) so the side with the 4 tumbler spring pockets faces up, pocket nearest to the cylinder head.
2. Insert the tumbler springs (2) into the 4 spring pockets. This side uses left tumblers.
3. Install the tumbler (3) for key cut position one in the slot nearest to the front of the lock cylinder. Install the remaining tumblers, key cut positions 3, 5, and 7, following the key code and same process. Press the tumblers in place until they are secure.
4. Check the correct loading of the tumblers by inserting the key into the cylinder. All tumblers should be flush with the lock cylinder body.
5. Turn the cylinder so the side with the 4 tumbler spring wells faces up. This side uses right tumblers.
6. Insert the tumbler springs into the 4 spring pockets.
7. The first tumbler closest to the front of the lock cylinder to be loaded will be the second key cut position, the second number in the key code. Install the remaining tumblers for the key cut positions 4, 6, and 8. Press the tumblers in place until they are secure.
8. Check the correct loading of the tumblers by inserting the key into the cylinder. All tumblers should be flush with the lock cylinder body.
9. Insert the key and lightly lubricate the cylinder body diameter and tumbler surfaces and a small amount in the head of the cylinder using the supplied grease.
10. Insert the sleeve (4) onto the cylinder assembly.
11. Insert the clutch (5) and driver (6) onto the cylinder (1).
12. Load the cylinder into the BO-49753 assembly tool so that the clutch (1) indexes with the notch in the opening of the tool (2).
13. Load the assembly tool with the lock cylinder into a vice and tighten the vice ONLY enough to hold the tool and lock the cylinder in place.
14. Insert the roll pin (7) into the driver (6) and install it using a 1/16 inch pin punch.
15. Insert the buffer (8) in the case (9), verify the buffer is properly seated.
16. Install the free wheel pin (11) in the sleeve (4) and clutch (5) and insert the assembly into the case (9).
17. With the lock cylinder assembly installed in the case (9), install the retainer (10) and stake the retainer in place using a small punch and hammer to peen the case material onto the exposed ends of the installed retainer (10).
18. Insert the key into the lock and function the lock to check for proper assembly and smooth operation.

Scheme 7

The door lock cylinder uses 8 of the 8 cut positions. The tumbler positions are staggered from side to side, 4 on one side and 4 on the other, are not self-retaining, and are not snap in.

1. Hold the door lock cylinder (1) so the side with the 4 tumbler spring pockets faces up, pocket nearest to the cylinder head.
2. Insert the tumbler springs (2) into the 4 spring pockets. This side uses left tumblers.
3. Install the tumbler (3) for key cut position one in the slot nearest to the front of the lock cylinder. Install the remaining tumblers, key cut positions 3, 5, and 7, following the key code and same process. Press the tumblers in place until they are secure.
4. Check the correct loading of the tumblers by inserting the key into the cylinder. All tumblers should be flush with the lock cylinder body.
5. Turn the cylinder so the side with the 4 tumbler spring wells faces up. This side uses right tumblers.
6. Insert the tumbler springs into the 4 spring pockets.
7. The first tumbler closest to the front of the lock cylinder to be loaded will be the second key cut position, the second number in the key code. Install the remaining tumblers for the key cut positions 4, 6, and 8. Press the tumblers in place until they are secure.
8. Check the correct loading of the tumblers by inserting the key into the cylinder. All tumblers should be flush with the lock cylinder body.
9. Insert the key and lightly lubricate the cylinder body diameter and tumbler surfaces and a small amount in the head of the cylinder using the supplied grease.
10. Insert the sleeve (4) onto the cylinder assembly.
11. Insert the assembly into the case (5).
12. With the lock cylinder assembly installed in the case (5), install the retainer (6) and stake the retainer in place using a small punch and hammer to peen the case material onto the exposed ends of the installed retainer (6).
13. Insert the key into the lock and function the lock to check for proper assembly and smooth operation.

Scheme 8

The ignition lock cylinder uses 8 key cut positions, 1-8. The ignition cylinder tumblers (3) are located on alternate sides of the cylinder (5). They are not snap-in and are not self-retaining. It follows the key code with the first tumbler being the first depth of the key code, closest to the head of the key.

1. Hold the ignition cylinder assembly (5) so the side with the tumbler spring pocket located closest to the head of the cylinder is facing up.
2. Insert the tumbler spring (7) into each of the 4 spring pockets of the cylinder assembly. This side of the cylinder used left tumblers.
3. The first tumbler (3) to be loaded will be the first key cut position, which is the first number in the key code. Install the tumbler in the slot over the spring. Install the remaining right tumblers following the key code and same process, pressing the tumblers in place until they are secure.
4. Rotate the cylinder assembly. Insert the tumbler spring into each of the spring pockets of the cylinder assembly. This side of the cylinder used right tumblers.
5. The first tumbler (3) to be loaded will be the second key cut position, the second number in the key code. Install the first tumbler in the slot over the spring. Install the remaining left tumblers following the key code and same process, pressing the tumblers in place until they are secure.
6. Inspect for correct loading of the tumblers by inserting the key into the cylinder. All tumblers should drop flush with the lock cylinder body diameter.
7. With the key in the cylinder assembly insert the round connector (6), insert the retainer spring (2) in the retainer slot located in the cylinder assembly. Insert the retainer (1) lining it up in the slot over the spring. Depress the retainer and hold.
8. Insert the cylinder into the sleeve (4) as shown in the print. Make sure the actuator stays located properly in the cylinder.
9. When the key is removed, the lock should stay together.
10. Lightly lubricate the outside surface in the tumbler area of in the lock body and down the key slot using the provided grease. Insert and extract the key 5 times to lubricate the keyway.
11. Insert the key and function the lock 3 times to distribute the grease inside the sleeve.
12. Verify the key position for inserting the lock into the column.

Rear Compartment Lid Lock Cylinder Coding

The door lock cylinder uses 8 of the 8 cut positions, 1-8. The tumbler positions are staggered from side to side, 4 on one side and 4 on the other, are not self-retaining, and are not snap in.

1. Hold the cylinder (5) so the side with the 4 tumbler spring pockets nearest the cylinder head faces up. This side uses left tumblers.
2. Insert the tumbler springs (8) into the 4 spring pockets.
3. Install the tumbler (6) for key cut position one in the slot nearest to the front of the lock cylinder. Install the remaining tumblers, key cut positions 3, 5, and 7, following the key code and same process. Press the tumblers in place until they are secure.
4. Check the correct loading of the tumblers by inserting the key into the cylinder. All tumblers should be flush with the lock cylinder body.
5. Turn the cylinder so the opposite side spring pockets faces up. This side uses the right tumbler.
6. Insert the tumbler springs into the 4 spring pockets.
7. The first tumbler closest to the front of the lock cylinder to be loaded will be the second key cut position, the second number in the key code. Install the remaining tumblers for the key cut positions 4, 6, and 8. Press the tumblers in place until they are secure.
8. Check the correct loading of the tumblers by inserting the key into the cylinder. All tumblers should be flush with the lock cylinder body.
9. Insert the key and lightly lubricate the cylinder body diameter and tumbler surfaces and a small amount in the head of the cylinder using the supplied grease.
10. Install 2 springs (4) into the 2 spring pockets in the head of the lock cylinder.
11. Holding the tumblers snap the shutter assembly (3) onto the cylinder.
12. Insert the cylinder into the case assembly (7) and install the cap (2) and the gasket double (1) around the cap.
13. Add the torsion spring (9).
14. Insert the rod clip (11) in the lever (10) and place it in the cylinder assembly.
15. Insert the E-clip (12) to securely hold the lever to the cylinder.
16. Insert the key into the lock and rotate it to check for proper assembly and smooth operation.

Lifting and Jacking the Vehicle

Note. The use of a LOW PROFILE LIFT ARMS SYSTEM may be required to avoid unwanted contact with the vehicle's body and structure depending on lifting equipment used. Refer to the manufacture's recommendation for their applications of low profile lift arms system for their lifting equipment.

Scheme 9

Vehicle Lifting- Frame Contact Lift

Front Lift Pads

When lifting the vehicle with a frame-contact lift, place the front lift pads on the rocker outer panel weld flange, as shown

Rear Lift Pads

When lifting the vehicle with a frame-contact lift, place the rear lift pads on the rocker outer panel weld flange, as shown.

Vehicle Jacking

Note. When you are lifting a vehicle with a service jack, block the wheels at the opposite end from which you are lifting. Use jack stands to provide additional support.

Front of Vehicle

When using a service jack under the front of the vehicle use one of the following locations

Place the service jack pad in the same location as shown for the front lift pads.

Rear of Vehicle

Note. Place jackstands ONLY under strong and stable vehicle structures.

Place the service jack pad in the same location as shown for the rear lift pads.

See also:
• Engine Identification (LAF, LEA, or LUK)
• Engine Identification
• Transmission Identification Information
• Transmission Identification Information
• Safety Glasses Warning