Tires & Wheels Cadillac Escalade GMT900

Fastener Tightening Specifications

Adhesives, Fluids, Lubricants, and Sealers

Scheme 1

Inspection Procedure

1. Inspect the front tire wear.
2. Inspect the rear tire wear.
3. Rotate the tires if any of the following conditions exist: The amount of time or mileage since the last tire rotation matches the maintenance schedule. The outer tread blocks are worn more than the middle tread blocks (1). The outer tread blocks are worn more than the inner tread blocks (2). The middle tread blocks are worn more than the outer tread blocks (4).
4. Measure the wheel alignment if any of the following conditions exist: The tread blocks have feathered edges (3). The outer tread blocks are worn more than the inner tread blocks (2). The inner tread blocks are worn more than the outer tread blocks (2).
5. Inspect the struts or the shock absorbers if the tire tread exhibits a cupped appearance (3).

Scheme 2

Tire waddle is a side to side movement at the front of the vehicle and/or the rear of the vehicle. Tire waddle can be caused by the following conditions

1. A steel belt not being straight within the tire
2. Excessive lateral runout of the tire
3. Excessive lateral runout of the wheel

The tire waddle is most noticeable at a low speed of about 8-48 km/h (5-30 mph). Tire waddle may appear as ride roughness at 80-113 km/h (50-70 mph). Tire waddle may appear as a vibration at 80-113 km/h (50-70 mph).

1. Raise and support the vehicle with safety stands. Refer to «Lifting and Jacking the Vehicle»(/cadillac/escalade/gmt900-2006-2014/remont/ignition-switchsteering-lock/#general-information__lifting-and-jacking-the-vehicle) .
2. Perform the following preliminary inspection: Mark the tire with a crayon in order to note the start and the stop position. Rotate each tire and wheel by hand. Inspect the tire for bulges or bent wheels. Replace as necessary.
3. Use tire substitution in order to identify the faulty tire. Perform the following steps for a tire substitution check: Use a comparable tire in order to replace each tire, one at a time. Test drive the vehicle. If the problem is tire or wheel related, you will eliminate the problem when you remove the faulty tire from the vehicle.

Wheel Mounting Surface Check

Replace any wheels that are bent or dented, or have excessive lateral or radial runout. Wheels with runout greater than specified may cause objectionable vibrations.

1. Thoroughly clean the wheel mounting surface with a clean shop towel and denatured alcohol, or equivalent.
2. Use a straight edge 203-229 mm (8-9 in) long. Place the straight edge on the wheel inboard mounting surface. Try to rock the straight edge up and down within the mounting surface.
3. For aluminum flat-mount wheels, repeat the procedure in step 2 on at least 3-4 different positions on the inboard mounting surface. If you can rock the straight edge, the mounting surface is bent and you must replace the wheel.
4. Inspect the mounting wheel/nut holes for damage caused from over-torquing the wheel/nuts. Inspect for collapsed wheel/nut bosses. Inspect for cracked wheel bosses.
5. For steel wheels, repeat the procedure in step 2 on at least 3-4 different positions on the inboard mounting surface. The outer mounting ring is designed to be raised slightly above the inner mounting ring. If you can rock the straight edge, the mounting surface is bent and you must replace the wheel.
6. Inspect the mounting wheel/nut holes for damage caused from over-torquing the wheel/nuts. Inspect for collapsed wheel/nut bosses. Inspect for cracked wheel bosses.
7. Replace the wheel if the wheel is bent.
8. Replace the wheel if the wheel/nut boss area is cracked.

Identify steel wheels with a 2 or 3-letter code stamped into the rim near the valve stem. Aluminum wheels have the code, the part number, and the manufacturer identification cast into the back side of the wheel.

Radial Tire Lead/Pull Correction

Aluminum Wheel Porosity Repair

1. Remove the tire and wheel. Refer to «Tire and Wheel Removal and Installation»(/cadillac/escalade/gmt900-2006-2014/remont/wheel-tire-system/#tires-wheels__tire-and-wheel-removal-and-installation) .
2. Inflate the tire to the manufactures specified pressure as stated on the tire.
3. Submerge the tire/wheel into a water bath in order to locate the leak.
4. Inscribe a mark on the wheel in order to indicate the leak areas.
5. Inscribe a mark on the tire at the valve stem in order to indicate the orientation of the tire to the wheel.
6. Remove the tire from the wheel. Refer to «Tire Dismounting and Mounting»(/cadillac/escalade/gmt900-2006-2014/remont/wheel-tire-system/#tires-wheels__tire-dismounting-and-mounting) .
7. Use number 80 grit sandpaper to scuff the inside of the rim surface at the leak area.
8. Use general purpose cleaner to clean the leak area.
9. Apply 3 mm (0.12 in) thick layer of adhesive/sealant to the leak area. Refer to «Adhesives, Fluids, Lubricants, and Sealers»(/cadillac/escalade/gmt900-2006-2014/remont/wheel-tire-system/#tires-wheels__adhesives-fluids-lubricants-and-sealers) .
10. Allow for the adhesive/sealant to dry.
11. Align the inscribed mark on the tire with the valve stem on the wheel.
12. Install the tire to the wheel. Refer to «Tire Dismounting and Mounting»(/cadillac/escalade/gmt900-2006-2014/remont/wheel-tire-system/#tires-wheels__tire-dismounting-and-mounting) .
13. Pressurize the tire to 276 kPa (40 psi).
14. Submerge the tire/wheel into a water bath in order ensure the leak is sealed.
15. Inflate the tire to the specified pressure as stated on the tire placard.
16. Balance the tire and wheel. Refer to «Tire and Wheel Assembly Balancing - Off Vehicle»(/cadillac/escalade/gmt900-2006-2014/remont/oem-general-information/#vibration-symptoms-diagnosis-and-correction__tire-and-wheel-assembly-balancing) .
17. Install the tire and wheel. Refer to «Tire and Wheel Removal and Installation»(/cadillac/escalade/gmt900-2006-2014/remont/wheel-tire-system/#tires-wheels__tire-and-wheel-removal-and-installation) .

Aluminum Wheel Refinishing Guidelines

Evaluating Damage

Note. Inspect the wheel for corrosion, scrapes, gouges, etc. Damage MUST NOT be deeper than what can be sanded or polished off. Inspect the wheel for cracks. If cracks are found, discard the wheel. ALL wheels with bent rim flanges must not be repaired or refinished. The re-machining and the re-clear coating of aluminum wheels is not recommended in the dealer environment due to concerns of repair durability. Do not use any re-machining process that removes aluminum. This could affect the dimensions and function of the wheel.

Aluminum Wheel Refinishing General Recommendations/Options

1. Painted aluminum wheels use a primer, color coat, and clearcoat procedure. If the paint is damaged, refinishing is possible. As with polished wheels, all original coatings must be removed first. Media blasting is recommended. (See option number 1).
2. If the clearcoat is damaged, it is possible to refinish with clearcoat only, however, the required refinishing process cannot be performed in the dealer environment. Refer to «Repair Option Number 2 - Outside Companies»(/cadillac/escalade/gmt900-2006-2014/remont/wheel-tire-system/#tires-wheels__repair-option-number-2-outside) .
3. Re-plating of chrome-plated aluminum wheels is not recommended.

Repair Option Number 1

Material Required/Information Resources

1. The Paint Manufacturer's Color Book
2. Refer to the latest GM Approved Refinish Materials Booklet (GM 4901 MD-2005) for specific products for aluminum refinishing.
3. To access the booklet, go to www.gmgoodwrench.com. Click on GM Collision Parts. Click on GM Technical Repair Information, select Paint Shop.
4. A Color Compatibility chart is also at this site defining what colors are used on what models.
5. Refer to specific Paint Manufacturers for refinish procedures and process pertaining to "Aluminum Refinishing". The procedure requires the wheel surface to be plastic media blasted to remove old paint or clearcoat.

General Color Selection

1. If the wheels being painted were previously clearcoated aluminum, and a painted aluminum look is desired, using Corsican Silver WAEQ9283 for a fine "aluminum-like" look, or Sparkle Silver WA9967 for a very bright look. Body color is another option to the customer that may also be used.
2. Some specific colors may be recommended on certain models.
3. If painting wheels that were previously clearcoated aluminum, it is recommended that all 4 wheels and their center caps be refinished to maintain color uniformity.

General Refinishing Procedures - Removal

1. Remove the wheels from the vehicle. The tires may remain mounted on the wheels.
2. Remove the balance weights and mark their locations on the tire.
3. Remove excess grease, etc. from the wheels with wax and grease remover.
4. Have the wheels plastic media blasted to remove the clearcoat.
5. Clean and mask and paint the wheels.

General Refinishing Procedures - Installation

1. Unmask the wheels.
2. Clean all wheel mounting surface of any corrosion, overspray, or dirt.
3. Install NEW coated balance weights at marked locations.
4. Install wheels on vehicle.

Repair Option Number 2 - Outside Companies

1. Some outside companies are offering wheel refinishing services. One such company, Transwheel Corporation (800-892-3733), provides this service with GM guidelines. Other companies may also exist.
2. Any process that re-machines or otherwise remanufactures the wheel should not be used.
3. The wheel ID must be recorded and follow the wheel throughout the process to assure that the same wheel is returned. The refinisher must permanently ID stamp the wheel and warrant the painted/clearcoated surfaces for a minimum of one year or the remainder of the new vehicle warranty, whichever is longer.
4. Paint and/or clearcoat must not be present on the following surfaces, the nut chamfers, the wheel mounting surfaces and the wheel pilot hole.
5. A refinishers responsibility includes inspecting for cracks using the Zyglo system or the equivalent. Any cracked wheels must not be refinished. No welding, hammering or reforming of any kind is allowed. A plastic media blast may be used for clean up of the wheel. Hand and/or lathe sanding of the machined surface and the wheel window is allowed. Material removal, though, must be kept to a minimum.

Tire and Wheel Removal and Installation

Special Tools

1. J 41013 Rotor Resurfacing Kit
2. J 42450-A Wheel Hub Resurfacing Kit

Removal Procedure

1. Raise and support the vehicle. Refer to «Lifting and Jacking the Vehicle»(/cadillac/escalade/gmt900-2006-2014/remont/ignition-switchsteering-lock/#general-information__lifting-and-jacking-the-vehicle) .
2. Remove the wheel center cap, if equipped.
3. Remove the wheel center cap nuts, if equipped.
4. Remove the wheel nuts.
5. Remove the tire and wheel assembly.
6. If the tire and wheel assembly is difficult to remove or cannot be removed, perform the following steps: Apply a small amount of penetrating oil to the wheel nuts, and the center hub. Allow a few moments for the penetrating oil to work. Loosen each wheel nut 2 complete turns. Lower the vehicle. Rock the vehicle from side to side. Repeat the procedure if necessary.
7. If the tire and wheel assembly still does not loosen, perform the following: Start the engine. Allow the vehicle to move forward, and quickly apply the brakes. Repeat this procedure in reverse. Repeat this procedure if necessary.
8. With the tire and wheel assembly loose, raise and support the vehicle.
9. Remove the tire and wheel assembly.
10. Using a wire brush or wire wheel, clean the rotor to the wheel or brake drum to wheel hub contact area.
11. Where possible, use the J 41013 to clean the contact areas of the wheel to brake rotor or brake drum.
12. Using the J 42450-A , clean the surface around the wheel studs.
13. Clean the threads of the wheel studs. If the threads are damaged, replace the wheel stud. For the front wheel stud replacement, refer to «Wheel Stud Replacement»(/cadillac/escalade/gmt900-2006-2014/remont/suspension-front/#front-suspension-system) . For the rear wheel stud replacement, refer to «Wheel Stud Replacement»(/cadillac/escalade/gmt900-2006-2014/remont/suspension-rear/#rear-suspension-system) .
14. After cleaning all the contact areas, use brake clean or denatured alcohol to remove all the penetrating oil, dirt and debris from the wheel nuts, brake rotor or brake drum.
15. Inspect and clean the contact area of the wheel. Refer to «Wheel Mounting Surface Check»(/cadillac/escalade/gmt900-2006-2014/remont/wheel-tire-system/#tires-wheels__wheel-mounting-surface-check) .

Installation Procedure

1. Install the tire and wheel assembly.
2. Hand start the wheel nuts.
3. Using the proper size socket and the torque wrench, tighten the wheel nuts in the proper sequence. Refer to «Fastener Tightening Specifications»(/cadillac/escalade/gmt900-2006-2014/remont/wheel-tire-system/#tires-wheels__fastener-tightening-specifications)
4. Install the wheel center cap, if required.
5. Install the wheel cap nuts, if required.
6. Remove the support and lower the vehicle.

Tire Repair

Scheme 3

Repairable area on a radial tire.

Note. NEVER repair tires worn to the tread indicators 1.59 mm (2/32 in) remaining depth. NEVER repair tires with a tread puncture larger than 6.35 mm (1/4 in). NEVER substitute an inner tube for a permissible or non-permissible repair. NEVER perform an outside-in tire repair (plug only, on the wheel). Every tire must be removed from the wheel for proper inspection and repair. Regardless of the type of repair used, the repair must seal the inner liner and fill the injury. Consult with repair material supplier/manufacturer for repair unit application procedures and repair tools/repair material recommendations.

Three basic steps for tire puncture repair

1. Remove the tire from the wheel for inspection and repair.
2. Fill the injury (puncture) to keep moisture out.
3. Seal the inner liner with a repair unit to prevent air loss.

External Inspection

1. Prior to demounting, inspect the tire surface, the valve and the wheel for the source of the leak by using a water and soap solution. Mark the injured area and totally deflate the tire by removing the valve core.
2. Demount the tire from the wheel and place the tire on a well-lighted spreader.

Internal Inspection

1. Spread the beads and mark the puncture with a tire crayon.
2. Inspect the inner tire for any signs of internal damage.
3. Remove the puncturing object, noting the direction of the penetration.
4. Probe the injury with a blunt awl in order to determine the extent and direction of the injury.
5. Remove any loose foreign material from the injury.
6. Punctures exceeding 6.35 mm (1/4 in) should not be repaired.

Cleaning

1. Clean the area around the puncture thoroughly with a proper liner cleaner, clean cloth and a scraper. This step serves to remove dirt and mold lubricants to insure proper adhesion and non-contamination of the buffing tool.
2. Refer to information on the product or manufacturer's Material Safety Data Sheet and follow guidelines for handling and disposal.

Clean the Injury Channel

1. Use a proper hand reamer, carbide cutter or drill bit to ream the puncture channel from the inside of the tire in order to clean the injury.
2. Remove steel wires protruding above the liner surface to prevent damage to the repair unit.
3. Consult your repair material supplier for recommended reaming tool(s).

Fill the Injury

1. It is necessary to fill the injury channel to provide back up for the repair unit and to prevent moisture from entering the tire fabric and steel wires.
2. For combination repair/plug units skip this step. Cement the injured channel and fill the injury from the inside of the tire with the repair plug per repair material manufacturer's recommendations. Without stretching the plug, cut the plug off just above the inside tire surface.
3. Consult your repair material supplier for proper repair material selection.

Repair Unit Selection

1. Center the repair unit over the injury as a reference and outline an area larger than the unit so that buffing will not remove the crayon marks.
2. Remove the repair unit.
3. DO NOT overlap previous or multiple repair units.
4. Consult your repair material supplier for proper repair unit selection.

Buffing

1. To prevent contamination and preserve the outline, buff within the marked area thoroughly and evenly with a low speed buffing tool using a fine wire brush or gritted rasp.
2. Buff to a smooth velvet surface (RMA #1 or #2 buffed texture).
3. Use caution not to gouge the inner liner or expose casing fabric.
4. Remove any buffing dust with a vacuum cleaner.
5. Consult your repair material supplier for a proper buffing tool.

Scheme 4

Apply chemical cement according to the repair material manufacturer's procedures.

Scheme 5

The tire must be in the relaxed position when the repair unit is installed. Do not spread the beads excessively.

Two-Piece Plug and Repair Units

1. If applicable, install the repair unit so that the alignment is correct.
2. Center the repair unit over the injury and stitch down thoroughly with the stitching tool, working from the center out.
3. Being careful not to stretch the plug material, cut the plug flush with the outer tread.

Combination Repair/Plug Units

1. Pull the plug through the injury until the repair just reaches the liner. Stitch down thoroughly.
2. Follow the repair material manufacturer's recommendations for further installation instructions. Consult your repair material supplier for the proper stitching tool.

Scheme 6

Some run flat tires may require more than 275 kPa (40 psi) to seat the bead. In such a case, a tire safety cage must be used. Consult the tire manufacturer for its individual repair policy.

Final Inspection

1. After remounting and inflating the tire, check both beads, the repair and the valve with a water and soap solution in order to detect leaks.
2. If the tire continues to lose air, the tire must be demounted and reinspected.
3. Balance the tire and wheel assembly. Refer to «Tire and Wheel Assembly Balancing - Off Vehicle»(/cadillac/escalade/gmt900-2006-2014/remont/oem-general-information/#vibration-symptoms-diagnosis-and-correction__tire-and-wheel-assembly-balancing) .

For additional tire puncture repair information, contact

Rubber Manufacturers Association (RMA)

1400 K Street, N.W., Suite 900

Washington

DC

20005-2403

Telephone: 202-682-4800

E-mail: informa.org

Website: www.rma.org

Tire Dismounting and Mounting

1. Remove the valve core from the valve stem.
2. Deflate the tire completely.
3. Use the tire changer in order to remove the tire from the wheel. Follow steps 4-7 to remove the tire from the wheel.
4. When separating the tire bead from the wheel, position the bead breaking fixture 90, 180 and 270 degrees from the valve stem.
5. Position the wheel and tire so the valve stem is at the 7 o'clock position relative to the head. The tire iron or pry bar can be inserted when prying the outer tire bead up and over the mounting/dismounting head.
6. Position the wheel and tire so the valve stem is again at the 7 o'clock position relative to the head. The tire iron or pry bar can be inserted when prying the inner tire bead up and over the mounting/dismounting head.
7. Remove all residual liquid sealant from the inside of the tire and wheel surfaces. If any tire sealant is noted upon tire dismounting on vehicles equipped with TPM, replace the tire pressure sensor. Refer to «Tire Pressure Indicator Sensor Replacement (Snap In Style)»(/cadillac/escalade/gmt900-2006-2014/remont/warning-system/#tire-pressure-monitoring-system) .
8. Use a wire brush or coarse steel wool in order to remove any rubber, light rust or corrosion from the wheel bead seats.
9. Apply mounting lubricant to the tire bead and the wheel rim. Refer to «Adhesives, Fluids, Lubricants, and Sealers»(/cadillac/escalade/gmt900-2006-2014/remont/wheel-tire-system/#tires-wheels__adhesives-fluids-lubricants-and-sealers) .
10. Position the rim so the valve stem (1) is at the 7 o'clock position relative to the head (2). This will protect the sensor when the bottom bead seats.
11. Using the tire machine, rotate the tire/wheel assembly clockwise when transferring the tire bead to the inside of the wheel rim. Ensure that the valve stem (1) is at the 7 o'clock position.
12. After the bottom bead is on the wheel, reposition the wheel and tire so that the valve stem (1) is at the 7 o'clock position relative to the head. This will protect the sensor while mounting the tire bead to the outside of the wheel.
13. Use the tire changer in order to install the tire to the wheel.
14. Inflate the tire until it passes the bead humps. Be sure that the valve core is not installed at this time.
15. Install the valve core to the valve core stem.
16. Inflate the tire to the proper air pressure.
17. Ensure that the locating rings are visible on both sides of the tire in order to verify that the tire bead is fully seated on the wheel.

Tools Required

J 39544-KIT Torque Socket Set

In order to equalize wear, rotate the tires at the specified intervals. Refer to Maintenance Schedule (North American Emissions) . In addition to scheduled rotation, rotate the tire and wheel assemblies whenever you notice uneven tire wear.

Radial tires tend to wear faster in the shoulder area, particularly in front positions, due to design. Radial tires in non-drive locations may develop an irregular wear pattern that can generate tire noise. This especially makes regular tire rotation necessary.

1. Raise and support the vehicle. Refer to «Lifting and Jacking the Vehicle»(/cadillac/escalade/gmt900-2006-2014/remont/ignition-switchsteering-lock/#general-information__lifting-and-jacking-the-vehicle) .
2. Remove the center caps from the wheels, if equipped.
3. Remove the tire and wheel assemblies. Refer to «Tire and Wheel Removal and Installation»(/cadillac/escalade/gmt900-2006-2014/remont/wheel-tire-system/#tires-wheels__tire-and-wheel-removal-and-installation) .
4. Rotate the 4 wheels and tires as shown.

1. Install the tire and wheel assemblies. Refer to «Tire and Wheel Removal and Installation»(/cadillac/escalade/gmt900-2006-2014/remont/wheel-tire-system/#tires-wheels__tire-and-wheel-removal-and-installation) .
2. Install the center caps, if equipped.
3. Lower the vehicle.
4. Check the tire pressure. Refer to the tire placard and adjust the tire pressure as necessary.
5. Perform the tire pressure sensor learn procedure, if equipped. Refer to «Tire Pressure Indicator Sensor Learn»(/cadillac/escalade/gmt900-2006-2014/remont/warning-system/#tire-pressure-monitoring-system) .

Tire Hoist Secondary Latch Mechanism

1. Rotate the hoist shaft counterclockwise until approximately 15 cm (6 in) of cable (1) is exposed.
2. While holding the latch pin (3), fully depress the latch button (2) and release the secondary latch from the hoist assembly. Some side-to-side and/or up-and-down movement may be necessary to disengage the latch mechanism.
3. Continue rotating the hoist shaft counterclockwise in order to lower the hoist the rest of the way.
4. If this does not release the secondary latch, the spare tire hoist will need to be replaced. See the following procedure.

1. If the vehicle is equipped with a spare tire stowage lock cylinder, open the spare tire lock cover on the bumper and using the ignition key, remove the lock.
2. Rotate the hoist shaft counterclockwise in order to lower the spare tire to the ground. Continue to rotate the shaft until the spare tire can be pulled out from under the vehicle and removed. If the spare tire does not lower to the ground, the secondary latch is engaged causing the tire not to lower.
3. If the secondary latch is engaged and the cable end is visible, perform the following procedure: Tighten the cable by rotating the hoist shaft clockwise until you hear 2 clicks or feel it skip twice. You cannot overtighten the cable. Loosen the cable by rotating the hoist shaft counterclockwise 3 or 4 turns. If the spare tire can be lowered, repeat steps 1 and 2 to see if the spare tire can be removed. If the spare tire cannot be lowered, rotate the hoist shaft counterclockwise until approximately 15 cm (6 in) of cable is exposed. Raise and support the vehicle. Refer to «Lifting and Jacking the Vehicle»(/cadillac/escalade/gmt900-2006-2014/remont/ignition-switchsteering-lock/#general-information__lifting-and-jacking-the-vehicle) . Place a transmission jack, or equivalent, under the spare tire. Position the center of the transmission jack under the secondary latch release button at the center of the spare tire. Arrange the arms of the transmission jack so they will support the tire after it has been released. Raise the jack until the spare tire stops moving upward and is firmly held in place, releasing the secondary latch. Lower the tire. If the spare tire is hanging by the cable, rotate the hoist shaft counterclockwise until the tire is low enough to remove.
4. If the secondary latch is engaged and the cable end is NOT visible, perform the following procedure: Raise and support the vehicle. Refer to «Lifting and Jacking the Vehicle»(/cadillac/escalade/gmt900-2006-2014/remont/ignition-switchsteering-lock/#general-information__lifting-and-jacking-the-vehicle) . Place a transmission jack, or equivalent, under the spare tire. Position the center of the transmission jack under the secondary latch release button at the center of the spare tire. Arrange the arms of the transmission jack so they will support the tire after it has been released. Raise the jack until the spare tire stops moving upward and is firmly held in place, releasing the secondary latch. Lower the tire and remove it from the jack.
5. Raise and support the vehicle if it is not already raised. Refer to «Lifting and Jacking the Vehicle»(/cadillac/escalade/gmt900-2006-2014/remont/ignition-switchsteering-lock/#general-information__lifting-and-jacking-the-vehicle) .
6. Depress the tabs, remove the guide shaft from the hoist collar, and slide the shaft toward the bumper.
7. Remove the collar from the hoist.
8. Remove the bolt.
9. Remove the hoist from the bracket.
10. Remove the spare tire hoist shaft guide from the bumper.

1. Install the spare tire hoist shaft guide to the bumper.
2. Install the hoist to the crossmember.
3. Install the bolt and tighten to 40 N.m (30 lb ft).
4. Install the collar to the hoist.
5. Install the shaft to the hoist.
6. Install the spare tire to the hoist.
7. Rotate the hoist shaft clockwise until the spare tire is in position and the hoist clicks 2 times or it skips twice. You cannot overtighten the cable.
8. Remove the safety stands.
9. Lower the vehicle.
10. Install the spare tire stowage lock cylinder.

Scheme 7

Most GM vehicles are equipped with steel belted all-season radial tires as standard equipment. These tires qualify as snow tires, with a higher than average rating for snow traction than the non-all season radial tires previously used. Other performance areas, such as wet traction, rolling resistance, tread life, and air retention, are also improved. This is done by improvements in both tread design and tread compounds. These tires are identified by an M + S molded in the tire side wall after the tire size. The suffix MS is also molded in the tire side wall after the TPC specification number.

The optional handling tires used on some vehicles now also have the MS marking after the tire size and the TPC specification number.

General Description

The factory installed tires are designed to operate satisfactorily with loads up to and including the full rated load capacity when these tires are inflated to the recommended pressures.

The following factors have an important influence on tire life

1. Correct tire pressures
2. Correct wheel alignment
3. Proper driving techniques
4. Tire rotation

The following factors increase tire wear

1. Heavy cornering
2. Excessively rapid acceleration
3. Heavy braking

Metric Wheel Nuts and Bolts Description

Metric wheel/nuts and bolts are identified in the following way

1. The wheel/nut has the word Metric stamped on the face.
2. The letter M is stamped on the end of the wheel bolt.

The thread sizes of metric wheel/nuts and the bolts are indicated by the following example: M12 x 1.5.

1. M = Metric
2. 12 = Diameter in millimeters
3. 1.5 = Millimeters gap per thread

Scheme 8

Replacement tires should be of the same tire performance criteria (TPC) specification number. This will ensure the same size, the same load range, and the same construction as those originally installed on the vehicle.

Replacement Wheels Description

Replace the wheel if any of the following conditions exist

1. The wheel exhibits excessive runout.
2. The wheel is bent.
3. The wheel is cracked.
4. The wheel is severely rusted.
5. The wheel is severely corroded.
6. The wheel leaks air.

Replace the wheel, the wheel studs and the wheel/nuts, or the wheel bolts if applicable, if any of the following conditions exist

1. The wheel has elongated bolt holes.
2. The wheel/nuts, or bolts if applicable, loosen repeatedly.

Steel wheel identification is stamped into the wheel near the valve stem.

Aluminum wheel identification is cast into the inboard side of the wheel.

Steel Wheel Repair Description

You can repair porosity in aluminum wheels. If leaks are found in a steel wheel, replace the wheel with a wheel of original equipment quality.

Tire Inflation Description

When you inflate the tires to the recommended inflation pressures, the factory-installed wheels and tires are designed in order to handle loads to the tire's rated load capacity. Incorrect tire pressures, or under-inflated tires, can cause the following conditions

1. Vehicle handling concerns
2. Poor fuel economy
3. Shortened tire life
4. Tire overloading

Inspect the tire pressure when the following conditions apply

1. The vehicle has been sitting at least 3 hours.
2. The vehicle has not been driven for more than 1.6 km (1 mi).
3. The tires are cool.

Inspect the tires monthly or before any extended trip. Adjust the tire pressure to the specifications on the tire label. Install the valve caps or the extensions on the valves. The caps or the extensions keep out dust and water.

The kilopascal (kPa) is the metric term for pressure. The tire pressure may be printed in both kilopascal (kPa) and psi. One psi equals 6.9 kPa.

Inflation Pressure Conversion (Kilopascals to PSI)

Tires with a higher than recommended pressure can cause the following conditions

1. A hard ride
2. Tire bruising
3. Rapid tread wear at the center of the tire

Tires with a lower than recommended pressure can cause the following conditions

1. A tire squeal on turns
2. Hard steering
3. Rapid wear and uneven wear on the edge of the tread
4. Tire rim bruises and tire rim rupture
5. Tire cord breakage
6. High tire temperatures
7. Reduced vehicle handling
8. High fuel consumption
9. Soft riding

Unequal pressure on the same axle can cause the following conditions

1. Uneven braking
2. Steering lead
3. Reduced vehicle handling

Refer to the Tire Placard for specific tire and wheel applications and tire pressures.

Scheme 9

The original equipment tires have tread wear indicators that show when you should replace the tires.

The location of these indicators are at 60 degree intervals around the outer diameter of the tire. The indicators appear as a 6 mm (0.25 in) wide band when the tire tread depth becomes 1.6 mm (2/32 in).

Special Tools

Illustration Tool Number/ Description J 39544-KIT Complete Torque Socket Set - 10 Pieces

Scheme 10

See also:
• Lifting and Jacking the Vehicle
• Vehicle Leads/Pulls
• Wheel Alignment Measurement
• Tire and Wheel Assembly Balancing - Off Vehicle
• Wheel Stud Replacement
• Wheel Stud Replacement
• Tire Pressure Indicator Sensor Replacement (Snap In Style)
• Maintenance Schedule (North American Emissions)
• Fastener Caution
• Tire and Wheel Removal and Installation
• Tire Dismounting and Mounting
• Adhesives, Fluids, Lubricants, and Sealers
• Repair Option Number 2 - Outside Companies
• Wheel Mounting Surface Check
• Fastener Tightening Specifications