SECTION 06-102.00 06-102.00/ 1 2010SE16 PRECAUTIONS GENERAL SAFETY RULES TO BE FOLLOWED WITH WARNING: Inflated tires can be very dangerous. Accidents, even fatal, could result from the incorrect handling and operation of bus wheels and tires. It is therefore of utmost importance that the precautions described in this section be carefully applied by all concerned in order to avoid bodily injury and costly damage. Repairs on wheels and tires can be dangerous and may entail risk to life and limb if proper precautions and training have not been ensured beforehand in the use of proper tools and appropriate equipment. Some local authorities impose strict regulations regarding the disposal of used tires. Contact your local authority to determine the proper method of disposal. RULES FOR APPROPRIATE HANDLING OF WHEELS 1. ALWAYS WEAR SAFETY GLASSES, SAFETY GLOVES, AND A DUST MASK when mounting or dismounting wheels and tires. 2. DO NOT CUT OR NICK THE WHEEL. Handle the wheels on a wooden floor or a rubber mat. Do not use hammers except those made of plastic, rubber or leather. 3. MAKE SURE THE ENTIRE WHEEL ASSEMBLY IS CLEAN when changing wheels or tires, and before mounting the wheels on the hubs. Remove rust, dirt and other impurities from all surfaces. Manual or electric wire brushes, sandblasting or chemical baths may be employed. 4. ALWAYS EXAMINE THE TIRE to detect damage before mounting it. 5. MAKE SURE THE INSIDE OF THE WHEEL AND THE TIRE ARE DRY before mounting. 6. THE USE OF A NON-WATER-BASED LUBRICANT IS RECOMMENDED when mounting tire on rims. 7. THE AIR USED TO INFLATE THE TIRE MUST BE ABSOLUTELY DRY. A drier to eliminate humidity from compressor air is essential. 8. DO NOT OVERINFLATE. Use the recommended inflation pressures. 9. NEVER ADD AIR TO A TIRE THAT HAS ROLLED COMPLETELY FLAT OR AT LESS THAN 80% RECOMMENDED PRESSURE. 10. NEVER USE PARTS THAT SEEM INAPPROPRIATE. 11. NEVER USE PARTS THAT ARE NOT APPROVED BY THE MANUFACTURER. 12. WHEN REPLACING A TIRE, ALWAYS RETAIN THE SAME SIZE AND TYPE OF TIRE.
2010SE16 2 /06-102.00 RULES FOR APPROPRIATE HANDLING OF WHEELS (CONTINUED) 13. NEVER INFLATE A TIRE IF THE TIRE DOES NOT SEEM CORRECTLY SEATED ON THE WHEEL. 14. NEVER USE A PRESSURE HIGHER THAN THAT RECOMMENDED to seat a tire correctly on the wheel. 15. NEVER APPLY INFLAMMABLE OR EXPLOSIVE PRODUCTS TO A TIRE. 16. NEVER WELD ON OR NEAR AN ASSEMBLED WHEEL WITH AN INFLATED TIRE. Do not weld or apply any heat source to the wheel for any reason. 17. NEVER HAMMER OR INSERT COMPONENTS TO CORRECT A PROBLEM WHEN THE TIRE IS COMPLETELY INFLATED. If the tire is not correctly seated, deflate the tire and repeat the process. 18. REAR DUAL WHEELS SHOULD BE PLACED SUCH THAT THE VALVE STEMS ARE AT 180 FROM ONE ANOTHER. CAUTION: For information on vehicle hoisting, see section 18: Hoisting and Towing. Also, always, refer to your internal safety procedure and use appropriate safety equipment for your protection. GENERAL DESCRIPTION See Figure 1 Nova LFS vehicles are equipped with hub-mounted wheels. Front wheels are mounted singly. Rear wheels are mounted in a dual assembly. When applicable, central wheels, installed on articulated vehicles, are mounted singly (one wheel). The type of wheel used utilizes two-piece collared nuts where the flange mates with the disk surface. Each front wheel and outside rear wheel is held in place by 10 wheel nuts. When wheels mounted on hubs are employed, all bolts and nuts have right-hand threads. This type of wheel requires a dry torque. The use of a lubricant, like anti-seize, will increase the clamping force and accelerate stud fatigue. A conventional air valve is standard on all wheels. However, the inside wheels of the double rear wheel assemblies are installed with a valve extension to facilitate inflating the rear tires. Finally, a hubodometer is installed on the right rear wheel of the vehicle. MOUNTING THE WHEELS AND TIRES REMOVAL For procedures and recommendations regarding wheel and tire removal, see the wheel manufacturer's servicing manual. INSTALLATION See Figures 2 and 3. WARNING: For installation of central wheels on articulated vehicles, see Annex B at the end of this document. Be careful when installing single mounted front wheels and single mounted middle wheels on the articulated vehicle. The wheel and tire sizes are quite different. do not mix them up. See Annex B at the end of this document.
06-102.00/ 3 2010SE16 VALVE HUBODOMETER FLANGED NUTS VALVE EXTENSION REAR WHEEL 00552 FRONT WHEEL Figure 1 - Front and Rear Wheel Mounting WARNING: Improper parts and incorrect installation procedures could cause a wheel to fail in service. A serious, even fatal, accident could result. Follow all instructions for inspecting and installing rims/ wheels. For all wheel assemblies, use only wheel nuts recommended by the wheel manufacturer. Do not substitute parts. + NOTE: For additional information and procedures regarding the proper installation of wheels, see the servicing manual provided by the wheel manufacturer. Also, refer to the installation procedure recommended by the Technology & Maintenance Council (TMC) in the Recommended Maintenance Practices Manual. 10 1 8 FLANGED NUTS 644 ± 34 N M (475 ± 25 LB-FT) 3 6 5 4 7 2 9 VALVE STEM 11 ±1 N M (8 ±1 LB-FT) Figure 2 - Tightening Pattern Figure 3 - Torque Values
2010SE16 4 /06-102.00 TIGHTENING PATTERN FOR WHEEL NUTS Tighten the wheel nuts in sequence on opposite sides of the wheel using the following method. A suggested tightening sequence is shown in Figure 2. 1. Lightly tighten the nuts (following the suggested sequence), so that the wheel is concentric with the hub. this is important. If not, the wheel may be eccentric with respect to the hub. In this initial operation, tighten the nuts only to correctly place the wheel. 2. Tighten the nuts progressively in the order shown in Figure 2, using a torque wrench, until the recommended torque value is reached. See Figure 3. Do not tighten each nut completely all at once; switch from one nut to another, so that the wheel is tightened uniformly. Start with nut #1, then #2 and so on, until all ten nuts are tight. To maintain safe assembly on the wheel studs, Nova Bus suggests you verify that wheel nut threads are, at minimum, flush with the nut. 3. Maintain the recommended torque values of the nuts, as indicated in Figure 3, by means of planned periodic audits. Proper maintenance schedules and operating conditions of the fleet will determine the frequency of these verifications. See the heading retorque intervals in this section for additional details. To ensure correct tightening, a large-sized torque wrench should be used. If a pneumatic impact wrench is used, it must serve only for the initial tightening of nuts in order to place the wheel correctly on the hub and must be gauged regularly. The final tightening must be performed with a torque wrench to ensure that all nuts are tightened equally and not beyond the limits indicated in Figure 3. CLAMP LOAD Once a tire and wheel assembly has been installed on a vehicle, it goes through a period of settling in. During this period, the components of the clamped assembly, including dust, dirt, paint and/or corrosion on wheel faces and stud threads, settle or move, which can result in a loss of clamp load. The amount of clamp loss may depend on the condition of the components, the method of installation, the number of times the wheels have been installed using the same fasteners, etc. Even new wheel installations lose clamp load. To ensure a proper clamp load is attained, it is essential to retorque the wheel nuts so the tire and wheel assemblies remain attached to the vehicle. RETORQUE INTERVALS The industry recommends retorquing the wheel nuts between 50 to 100 mi (80 to 160 km) following tire and wheel installation on the vehicle. After that, it is recommended to check the wheel nuts at routine maintenance intervals or at maximum intervals of 10,000 mi (16,000 km). If the vehicle is subject to difficult operating conditions, the nuts should be checked daily, regardless of the distance travelled. ESTABLISHING A FLEET-SPECIFIC RETORQUING INTERVAL It is possible to establish a specific interval for a fleet or vehicle based on operating conditions and wheel torque history. To determine the adequate retorquing interval, it is necessary to determine the amount of torque loss that routinely occurs on wheel assemblies after installation. 1. Follow the recommended installation procedure. 2. Set final torque with a calibrated torque wrench. 3. Record the condition of the hardware using the Wheel nut torque check form. See Table 1. + NOTE: Before proceeding, replace any fasteners that are unserviceable. The condition of hardware will affect clamp load on the wheel. 4. Drive the loaded vehicle on a route where it can make several turns on entrance/exit ramps for a minimum of 5 mi (8 km) and return. The length of this short run may vary depending on individual fleet conditions, such as payload, age of equipment, road conditions, etc. A loaded vehicle is required. 5. Measure torque with a calibrated torque wrench and record data again. 6. A statistical sample or multiple checks should be made on a representative range of vehicles and operating conditions. If retorque values are abnormally low, remove the wheels to find and correct the problem. If retorque values are consistently low, review the assembly and maintenance practices. If the retorque value is below the acceptable torque range, retorquing is necessary and a retorque program is needed. If the retorque values are consistently within the required range for the wheel system, the retorque interval may be extended. 7. After a retorque interval has been established, it is recommended to continue to collect data periodically to ensure the program remains sound. This can be done by spot-checking on a regular basis, or by collecting data throughout the year. At least 30 randomly selected wheel ends should be included in the sample. + NOTE: To make sure the same nuts are checked during the retorque check, mark the nut that is on the righthand side of the valve stem and follow the same sequence used to apply installation torques.
06-102.00/ 5 WHEEL NUT TORQUE CHECK 2010SE16 UNIT # YEAR TORQUE REQUIRED INSTALLATION DATE MILEAGE CONDITION OF HARDWARE (studs / nuts) NEW GOOD FAIR POOR 1 Right Front INSTALLATION TORQUE 1 2 3 4 5 6 7 8 9 10 2 Left Front 3 Left Rear Inside 4 Left Rear Outside 5 Right Rear Inside 6 Right Rear Outside 7 8 Right Middle (Articulated vehicles only) Left Middle (Articulated vehicles only) 1 Right Front RETORQUE CHECK 1 2 3 4 5 6 7 8 9 10 2 Left Front 3 Left Rear Inside 4 Left Rear Outside 5 Right Rear Inside 6 Right Rear Outside 7 8 Right Middle (Articulated vehicles only) Left Middle (Articulated vehicles only) NUMBER BELOW TORQUE RANGE Table 1 - Wheel Nut Torque Check Form
2010SE16 6 /06-102.00 MAINTENANCE OF WHEELS + NOTE: To obtain the proper wheel maintenance instructions, see the manufacturer s servicing manual. Also, refer to the installation procedure recommended by the Technology & Maintenance Council (TMC) in the Recommended Maintenance Practices Manual. It is important to follow the proper procedures to help reduce overheating and to prolong the life span of the wheels. Examine wheels frequently for danger-free operation. During tire inspections or periodic maintenance checks, verify the rims and tires for the following conditions (particular attention should be paid to the front axle and frequently exposed areas): Missing valve caps. Missing, worn or loose wheel nuts. Broken studs. Replace the broken stud and the stud on each side of the broken one. Rust streaks extending from the bolt holes. Cracks in flange of wheel nuts. Wheel not mounted properly. Cracks or damage on any wheel component. Pitting or corrosion that has reduced the metal thickness. Wheel nuts must be kept tight. Ridges of dirt coming off the wheel nuts may indicate loosening. See the heading retorque intervals in this section for additional details. Also, check the rims, the bead seat, the rings and the assembly surface for damage. MAINTENANCE AND PROTECTION IN CORROSIVE ENVIRONMENTS Certain agents used for snow removal, such as salt, calcium, and other very alkaline materials, may cause damage to the wheels. It is sufficient to wash them (do not use highly alkaline cleaning products) to keep them in good condition for several years. However, if the air used to fill tubeless tires is not dry, the areas of the wheel beneath the tire casing can become severely corroded. When such conditions are encountered, the following wheel cleaning and protection practice is recommended: 1. Frequently steam-clean or clean with water from a highpressure hose. Use of a mild detergent will accelerate the cleaning process. 2. When the tires are removed, the entire wheel should be cleaned and examined. Bead seat and valve stem corrosion often are caused by trapped moisture that contains corrosive elements. 3. Mild corrosion should be removed thoroughly by wire brush and the rim protected with a coating of tire lubricant, such as Freylube or the equivalent. 4. Remove any severely corroded wheel from service. For more information concerning the protection of rims, see the wheel manufacturer s maintenance manual. TIRE MAINTENANCE One of the most important factors in vehicle operation is systematic and correct tire maintenance. The tires not only support the weight of the loaded vehicle, but also are integral parts of the drive train and braking systems. Therefore, tires must receive careful, systematic and regular maintenance, as with other operating units. Certain tires are not recognized for installation on certain disk-type wheels used on buses mentioned in this manual. For more information on this matter, see the tire manufacturer s manual. INFLATING TIRES For instructions, see the tire manufacturer s manual. For the recommended tire pressure, see the Nova Bus operator's manual.
TROUBLESHOOTING GUIDE 06-102.00/ 7 Problem Possible cause Remedy Abnormal tire wear. (Abnormal tire wear is any type of wear that results from a suspension or alignment problem, an internal tire fault, or driving on underinflated or overinflated tires, resulting in bumpy, directional, feathered or cupped wear patterns developing on the tread. Wheel wobbles. Tire and wheel related vibrations. (Run tires until warm to eliminate any flat spots following parking). Wanders/pulls. Sways/pitches. Front wheel shimmy. No recovery (Steering wheel does not return to center). a. Tire pressure incorrect. b. Worn suspension. c. Improper toe-in. d. Wheels, tires, or brake disks or drums out of balance. a. Bent wheel. b. Wheel bearings out of adjustment or damaged. c. Misaligned wheels. a. Improper balance of wheel/tire. b. A tire poorly seated on the rim. c. A heavy spot in the tire. d. A stiff spot in the tire. e. An out-of-round tire. a. Tires worn or improperly inflated. b. Wheel alignment incorrect. c. Hub bearing worn. d. Front or rear suspension parts loose or broken. e. Steering gear out of adjustment or broken. a. Tires improperly inflated. b. Stabilizer bar bent or broken. c. Shock absorber worn out. a. Tires worn or improperly inflated. b. Wheels out of balance. c. Shock absorber worn out. d. Wheel alignment incorrect. e. Hub bearings worn. f. Ball joints or bushings worn. g. Steering gear out of adjustment or broken. a. TIRES Worn or separated belt. b. FRONT END - Components - King pins - Tie rod ends - Drag link Front-end alignment not to specifications. - Excessive toe - Insufficient caster c. REAR END AND CENTRAL AXLE Axles out of alignment, or worn/bent suspension components. d. STEERING COLUMN Insufficient lubrication, or bent steering shaft. e. STEERING GEAR Restricted power steering, or out of adjustment/ failing steering gear box, bent or misaligned steering gear mounting bracket. a. Correct tire pressure. b. Inspect and replace worn suspension parts. c. If wear is in front tires, adjust toe-in. If wear is in rear tires check rear suspension for damage. d. Replace as necessary. a. Replace wheel. b. Adjust bearings. c. Check wheel alignment. a. Check for missing weights, mud or dirt packed in the back of the rim or debris embedded in the tread. Replace weights. Clean out any dirt or debris. b. Reseat tire on rim. c. Rebalance tire. d. Rebalance tire. e. Replace tire. a. Replace tire or inflate tires to proper pressure. b. Check wheel alignment. c. Replace hub bearing. d. Tighten or replace suspension parts. e. Adjust or repair steering gear. a. Inflate tires to proper pressure. b. Inspect stabilizer bar. c. Replace shock absorber. a. Replace tire or inflate tires to proper pressure. b. Balance wheels. c. Replace shock absorber. d. Check front wheel alignment. e. Replace hub bearings. f. Inspect ball joints and bushings. g. Adjust or repair steering gear. a. Replace tires. b. Replace worn or damaged parts. Ensure proper alignment. c. Replace worn or damaged parts. Ensure proper alignment. d. Ensure proper lubrication of components. Replace any damaged parts. e. Verify steering gear for proper functioning, and replace any damaged parts. 2010SE16 Table 2 - Troubleshooting Guide
2010SE16 8 /06-102.00 TROUBLESHOOTING GUIDE Problem Possible cause Remedy Wheel becomes detached. a. Loose wheel nuts. b. Over-torqued wheel nuts. c. Worn or cracked rims. (Cracking of a rim occurs most frequently due to overtorqued wheel nuts). d. Wheel bearing failure. (Contamination of the lubricant by road debris, water or other particles. Bearing damage occurring during installation or incorrect or substandard bearings installed). e. Spindle or spindle hardware failure. (The hub to spindle nut is cracked or damaged, cross-threaded, over-tightened or not safety locked. Road damage occurred, resulting in bent or weakened spindle. Prior bearing failure resulted in sufficiently high temperatures being applied to the spindle to weaken its ability to survive under service conditions). f. Tire and wheel imbalance. (Several reasons may account for a wheel imbalance. The loss of wheel weights, inconsistent tire inflation pressure, adhesions and accumulation of road accretions and internal tire ply delamination. Improper balancing or lack of balancing during routine wheel maintenance). g. Acceleration of the rate of component fatigue from vehicle weight and/or load factors. a. Ensure that wheel nuts or wheel-to-hub faces are contacting clean metal surfaces. Ensure recommended torque values and correct sequencing are employed. Ensure all stud threads are clean and in good condition. b. Replace all wheel nuts or studs that have been overtorqued. c. Conduct repairs immediately. d. Insufficient lubrication or the wrong type or grade of lubricant selected. An oil-filled component is leaking, has cracked or broken inspection cover or missing fill plug. e. Check for structural flaw in the material. f. Check wheel weights, Maintain proper tire pressures. Pressure clean wheels as part of regular maintenance. Verify integrity of tires. g. Increase inspection and routine maintenance scheduling. Table 2 - Troubleshooting Guide (Continued)
06-102.00/ 9 2010SE16 SECTION 06-102.00A ALCOA WHEELS WEAR AND REPLACEMENT OF RIMS Rim flange wear occurs at the rim edge near the contact area with the tire bead seat. This is due to the interaction between the tire sidewall and the wheel rim edge primarily as a result of tire sidewall flex during normal operation. This wear can be aggravated by dirt and grime in this contact area. Other contributing factors are the loads carried. Loads with a high center of gravity will tend to increase the lateral movement, resulting in increased sidewall flex and rim flange wear. Road conditions also contribute, in that secondary roads with many twists and turns will accentuate this lateral movement and bead flex. Rim flange wear can be reduced by using tires with stiffer side walls and ensuring that the tire pressure is within the manufacturer s recommendations for the loads carried. The Alcoa rim flange gauge (Figure A1) can be used to measure the flange of Alcoa wheels along with an interpretation guide. The gauge represents an amount of the wheel flange that can be worn out. At this point we require that the wheel be removed from service. Until this stage of wear is reached a file or grinder can be used to break any sharp edge that is generated on the inner edge of the wear area on the wheel flange. This will help prevent any damage to the tire sidewall. If the height of the flange prevents the gauge from resting flat against the bead seat, it is acceptable to keep the rim in service, as shown in Figures A2(i) and A2(ii). If the gauge sits firmly on the bead seat area and there is a gap between the flange and the gauge, then the wheel should be removed from service, as shown in Figures A2(iii) and A2(iv). (i) (ii) RIM GAUGE WHEEL RIM RIM ACCEPTABLE RIM GAUGE WHEEL RIM RIM ACCEPTABLE THIS GAP LARGER THAN THIS (iii) RIM NOT ACCEPTABLE ALCOA RIM FLANGE GAUGE RIM GAUGE DAYLIGHT IN THIS AREA INDICATES EXCESSIVE WEAR 02475 (iv) WHEEL RIM RIM NOT ACCEPTABLE Figure A1 - Alcoa Rim Flange Gauge Figure A2 - Interpretation Guide
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06-102.00/ 11 SECTION 06-102.00B MIDDLE WHEELS-ARTICULATED VEHICLE 2010SE16 INSTALLATION WARNING: For installation of middle wheels on articulated vehicles, ensure the correct orientation of the wheel during installation. If the wheel is installed the wrong way, it will bind on the underbody. There is a 34 mm offset toward the outside of the wheel. See Figure 1B. The Nova LFS articulated vehicle is equipped with a single wide tire on the middle axle. The tire information is listed below, together with data for conventional tires installed on the front and rear axles of a Nova LFS articulated vehicle. The installation of the single extra wide tire on the middle axle is no different than conventional bus tires installed on the front and rear axles. The same tools used for a conventional tire change are required for the extra wide tire. Mount the wheel with heavy two piece flange nuts (31mm hgt) as used on the drive axle wheels. See Figure 1B for torque value of wheel nuts. In order to ensure proper mounting of the extra wide tire, maintenance personnel are required to install these tires with the air valve accessible to the outboard side. Description Tire Size Tire Width Tire Weight Axle Positions Extra Wide Tire 385/55 R22.5 15 inches 145 lb (66 kg) Middle Low Floor Tire 305/70 R22.5 9 inches 133 lb (60 kg) Front and Rear Table 1B - Tire Data (Articulated Vehicle) TORQUE FLANGED NUTS TO: 475 ± 25 LB-FT (644 ± 34 N M) INBOARD OFFSET 34 + 2 mm HEAVY TWO PIECE FLANGE NUT AIR VALVE 8 ±1 LB-FT (11 ±1 N M) OUTBOARD MIDDLE WHEEL (ARTICULATED VEHICLES ONLY) Figure 1B - Middle Wheel for Extra Wide Tire on Articulated Vehicle
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