Manufacturer communication — 2006 GMC YUKON DENALI XL

• Applies to 2013 and prior GM passenger cars and light duty trucks.

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  2013 and Prior GM Passenger Cars and Light Duty Trucks

• The most common ride concern involving tire radial force variation is a shake on smooth roads at highway speed, 105-115 km/h (65-70 mph).

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  The most common ride concern involving tire radial force variation is highway speed (105-115 km/h (65-70 mph) shake on smooth roads.

Possible causes

• Tire related smooth road highway speed shake has three causes - imbalance, out of round and tire force variation - which are not necessarily related; all three must be addressed.

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  Tire related smooth road highway speed shake can be caused by three conditions: imbalance, out of round and tire force variation. These three conditions are not necessarily related. All three conditions must be addressed.

Steps to confirm (in the document’s order)

1. With the vehicle raised, centre the wheels on the hub: loosen all wheel nuts, hand-tighten them while shaking the wheel, then torque to specification with a torque wrench, not a torque stick.

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   With the vehicle raised, ensure the wheels are centered on the hub by loosening all wheel nuts and hand-tightening all nuts first by hand while shaking the wheel, then torque to specifications using a torque wrench, NOT a torque stick.

2. On the EVA, 35 to 50 Hz typically indicates a first order propshaft vibration (see bulletin 08-07-30-044); 10 to 20 Hz generally indicates a tire/wheel vibration.

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   A reading of 35 to 50 Hz typically indicates a first order propshaft vibration. If this is the situation, refer to the latest version of Corporate Bulletin Number 08-07-30-044. Generally, a reading between 10 and 20 Hz indicates a tire/wheel vibration and if this is the reading obtained, continue using this bulletin.

3. Flat-spotting vibration may come and go above 72 km/h (45 mph) during the first 10 minutes; if vibration continues after 10 minutes of driving above 72 km/h (45 mph), flat-spotting can be ruled out.

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   Tire flat-spotting vibration may come and go at any speed over 72 km/h (45 mph) during the first 10 minutes of operation, if vibration continues after 10 minutes of driving at speeds greater than 72 km/h (45 mph), tire flat-spotting can be ruled out as the cause for vibration.

4. Check each assembly on a calibrated off-car dynamic balancer; if any assembly calls for more than 1/4 ounce on either rim flange, remove all weights and rebalance as close to zero as possible.

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   If any assembly calls for more than ¼ ounce on either rim flange, remove all balance weights and rebalance to as close to zero as possible.

5. Guide values for assembly radial force variation: P-Metric tires on light trucks 24 lbs (11 kg) or less, LT-tires on light trucks 35 lbs (16 kg) or less.

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   P-Metric tires on light trucks 24 lbs (11 kg) or less LT-tires on light trucks 35 lbs (16 kg) or less

Repair

1. If the radial runout of an assembly exceeds 0.040 in (1.02 mm), match mount the tire to the wheel to get below 0.040 in (1.02 mm).

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   If one or more of the tire/wheel assemblies are more than 0.040 in (1.02 mm), match mount the tire to the wheel to get below 0.040 in (1.02 mm).

2. If match mounting on in-spec wheels still gives values above the guide, tire replacement may be necessary; replacing tires at lower values probably condemns good tires.

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   If match mounting tires to in-spec wheels produces assembly values higher than these, tire replacement may be necessary. Replacing tires at lower values will probably mean good tires are being condemned.

Caution

• Before measuring tires on force variation equipment, the vehicle must be driven at least 24 km (15 mi) to remove any flat-spotting.

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  Before measuring tires on GM approved tire force variation measurement equipment, the vehicle MUST be driven a minimum of 24 km (15 mi) to ensure removal of any flat-spotting.

• On the balancer, always centre the wheel on the pilot bore with the proper cone/collet; never use the hub-cap bore, which is not a precision machined surface.

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  Be sure to choose the proper cone/collet for the wheel, and always use the pilot bore for centering. Never center the wheel using the hub-cap bore since it is not a precision machined surface.