Buick Encore: Description and operation

All seasons tires descriptio

Fig. 16: Identifying All Seasons Tire Marking

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:

• Correct tire pressures
• Correct wheel alignment
• Proper driving techniques
• Tire rotation

The following factors increase tire wear:

• Heavy cornering
• Excessively rapid acceleration
• Heavy braking

METRIC WHEEL NUTS AND BOLTS DESCRIPTION

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

• The wheel/nut has the word Metric stamped on the face.
• 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.

• M = Metric
• 12 = Diameter in millimeters
• 1.5 = Millimeters gap per thread

P-METRIC SIZED TIRES DESCRIPTION

Fig. 17: Identifying P-Metric Sized Tire Marking

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:

• The wheel exhibits excessive runout.
• The wheel is bent.
• The wheel is cracked.
• The wheel is severely rusted.
• The wheel is severely corroded.

NOTE: Air leaks caused by porosity on aluminum wheels are repairable.

WARNING: If you are replacing the wheel(s), the wheel stud(s), the wheel nut(s) or the wheel bolt(s), install only new GM original equipment parts.

Installation of used parts or non-GM original equipment parts may cause the wheel to loosen, loss of tire air pressure, poor vehicle handling and loss of vehicle control resulting in personal injury.

• The wheel leaks air.

CAUTION:

The use of non-GM original equipment wheels may cause:

• Damage to the wheel bearing, the wheel fasteners and the wheel
• Tire damage caused by the modified clearance to the adjacent vehicle components
• Adverse vehicle steering stability caused by the modified scrub radius
• Damage to the vehicle caused by the modified ground clearance
• Speedometer and odometer inaccuracy

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

• The wheel has elongated bolt holes.
• 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

CAUTION: Do not heat wheels in an attempt to soften them for straightening or repair damage from striking curbs, etc. Do not weld wheels. The alloy used in these wheels is heat-treated and uncontrolled heating from welding affects the properties of the material.

CAUTION: The use of tubes in tubeless tires is not a recommended repair due to the fact that speed ratings are greatly reduced.

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:

• Vehicle handling concerns
• Poor fuel economy
• Shortened tire life
• Tire overloading

Inspect the tire pressure when the following conditions apply:

• The vehicle has been sitting at least 3 hours.
• The vehicle has not been driven for more than 1.6 km (1 mi).
• 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:

• A hard ride
• Tire bruising
• Rapid tread wear at the center of the tire

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

• A tire squeal on turns
• Hard steering
• Rapid wear and uneven wear on the edge of the tread
• Tire rim bruises and tire rim rupture
• Tire cord breakage
• High tire temperatures
• Reduced vehicle handling
• High fuel consumption
• Soft riding

Unequal pressure on the same axle can cause the following conditions:

• Uneven braking
• Steering lead
• Reduced vehicle handling

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

Tires and wheels description and operation

Balancing Tires

There are two types of tire and wheel balancing: static and dynamic.

Static balance is the equal distribution of weight around the wheel. Assemblies that are statically unbalanced cause a bouncing action called wheel tramp. This condition may eventually cause uneven tire wear.

Fig. 18: Tire And Wheel Balancing Diagram (1 of 2)

Dynamic balance is the equal distribution of weight on each side of the centerline so that when the assembly spins there is no tendency for it to move from side to side. Assemblies that are dynamically unbalanced may cause wheel shimmy.

Fig. 19: Tire And Wheel Balancing Diagram (2 of 2)

General Balance Precautions

Remove all deposits of foreign material from the inside of the wheel.

WARNING: Stones should be removed from the tread to provide accurate wheel balancing and to avoid operator injury (from stones becoming dislodged while wheel is in motion) during the procedure.

Inspect the tire for any damage. Balance the tire according to the equipment manufacturer's recommendations.

Wheel Weights

If more than 85 grams (3.0 ounces) are needed to static balance the wheel, split the wheel weights as equally as possible between the inboard and the outboard flanges.

Balancing the assemblies with factory alloy wheels requires the use of special nylon-coated, clip-on wheel weights. These weights are designed to fit over the thicker rim flange of the alloy wheel. Install these weights with a plastic-tipped hammer.

Adhesive wheel weights are also available. Use the following procedure to install adhesive wheel weights

Fig. 20: Identifying Wheel Weights

Adhesive Wheel Weight Installation

1. Clean the wheel by sanding it to bare alloy where the wheel weight will be installed.
2. Use a clean cloth or paper towel saturated with a mixture of half isopropyl alcohol and half water to wipe the place where the wheel weight will be installed.
3. Dry the area with hot air. The surface of the wheel should be warm to the touch.
4. Warm the adhesive backing on the wheel weights to room temperature.
5. Remove the tape from the back of the weights. Do not touch the adhesive surface.
6. Apply the wheel weight and press it on with hand pressure
7. Secure the wheel weight with a 70-110 N (16-25 lb) force applied with a roller.

Tire Chain Usage

Due to limited tire-to-body clearance on certain vehicles, recommendations for tire chain use are published in the Owner's Manual. When tire chains need to be used, most current General Motors vehicles require SAE Class "S" tire chains. These may also be designated as 1100 Series, type PL tire chains. These chains are specifically designed to limit the "fly off" effect which occurs when the wheel rotates.

Be sure that only fine-link chains are used which do not add more than 15 mm (0.590 in), including the lock, to the tread surface and the inner sides of the tires. Manufacturers of tire chains have a specific chain size for each tire size to ensure a proper fit when the chain is installed. Be sure to purchase the correct chains for the tires on which they are to be used. Use rubber adjusters to take up any slack or clearance in loose chains.

Use of chains may adversely affect vehicle handling. When tire chains are installed, follow these precautions:

• Adjust speed to road conditions
• Avoid sharp turns
• Avoid locked-wheel braking

To prevent chain damage to the vehicle, install the chains on the front tires as tightly as possible. Tighten them again after driving 0.4-0.8 kilometer (0.3-0.5 mile). The use of chains on the rear tires is not recommended because they may contact the vehicle and possibly damage it. If chains must be used on the rear tires, be sure there is sufficient clearance between the chains and the body. Do not exceed 70 km/h (45 mph) or the chain manufacturer's speed limit, if lower. Avoid large bumps, potholes, severe turns and any other maneuvers which could cause the tires to bounce. Follow any other instructions of the chain manufacturer which do not disagree with the above instructions.

TREAD WEAR INDICATORS DESCRIPTION

Fig. 21: View Of Tread Wear Indicators

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 AND EQUIPMENT

SPECIAL TOOLS

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