Heavy Equipment Technician

Wheels, Tires and Hubs

Suspension, Wheels and Systems First Period Module 190102d Objectives

1. Identify common wheel types and mounting designs..

2. Explain tire construction, care and maintenance in relation to design..

3. State the safety procedures required when handling tires and wheels.. Objectives

4. Perform wheel removal, inspection and installation..

5. Explain wheel balancing..

6. Diagnose wheel and tire faults. Objective One

Identify common wheel types and mounting designs. Wheel Types: Spoke Wheels: Spoke A spoke wheel is a Wheel heavy casting, and may be called a spider or a Dayton Wheel..

Spoke wheels are Brake mounted with two Drum bearings on the axle shaft, and may have three, five or six spokes..

The brake drum is bolted to the spider. Wheel Types:

Spoke Wheels: Continuous Side Ring Multi piece rims are Rim Base typically composed of a rim base, a solid Split Lock continuous side ring Ring and a split lock ring.. Rim Clamp & Sometimes referred to Nut as a de-mountable rim. Wheel Types: Spoke Wheels: Brake Drum Rim and tire assembly are attached to the Continuous spider studs by wedge Side Ring shaped clamps and Spoke nuts. Wheel Rim Base Split Lock Ring Rim Clamp & Nut Wheel Types: Spoke Wheels: May have a sight glass and lubricant filler plug on a non driving wheel..

When dual tires are located on one wheel, a spacer is used in between the two tires to prevent them from contacting each other. Spacer Wheel Types: Spoke Wheels: Spacer Types Corrugated Corrugated Spacer Channel Spacer

Spacer width adjusts the depth of rim clamps. Ensure that a minimum of two to three threads passes the face of the retaining nut. Wheel Types: Disc Wheels: Also known as a Bud wheel.

Disc wheels are composed of a rim and disc that are welded together, and may use a removable side ring and locking ring, for easier tire assembly..

Usually uses tubeless tires. Wheel Types: Inboard Brake Drum Disc Wheels: Brake Disc Wheel Drum Stud Bolt Wheel An inboard Brake Hub Drum mounting is located to the rear Spindle of the wheel hub. Adjusting The hub is separate Nut from the wheel, Washer unlike the spoke Wheel wheel’s hub which Bearings Wheel is part of the wheel. Hub Seal Wheel Types: Outboard Brake Drum Disc Wheels: Disc Brak An Outboard Brake Wheel e Drum mounting is Stud Bolt Wheel Drum located at the front Hub of the wheel hub. Adjusting Nut Spindle

Washer Wheel Hub Seal Wheel Bearings Wheel Types:

Stud Piloted Disc Wheels: Head Type Stud piloted disc wheels have Wheel Stud cone shaped recessed stud holes, and the hub is mounted and centered by the studs and cone shaped wheel nuts..

It is critical that the tapered Taper portion of the nut enters the tapered stud hole of the disc wheel, or the wheel will come loose. Wheel Nut Wheel Types: Stud Piloted Disc Wheels: When dual wheels are Taper Inner used, a special nut is Wheel required to secure the inside wheel and provide a threaded surface for the outer wheel nut.. Taper Hub The special nut has two tapered shoulders to center the inner wheel and outer wheel, and is also threaded to act as a stud for the outer wheel and nut. Wheel Types: Nut Threads Hub Piloted Disc Wheels: Nut Body Uses the center section of the hub itself, to center the Flange wheel or wheels.. Disc Wheels

The nuts are for clamping the wheel to hub only.

Hub Wheel Types: Caution: Hub Piloted Stud Piloted Stud Piloted Wheel Wheel Wheels

Flange Hub Hub Cone Nut Nut Use proper hardware for mounting wheels. Aluminum wheels are thicker and need longer mounting studs. Objective Two Explain tire construction, care and maintenance in relation to design Tube Type Tires

Side Ring Flap

Locking Disc Ring Wheel Tube & Valve Stem Tire Tube type tire installations can involve many components as well as multi-piece rims, matching of component parts is critical. Tubeless Type Tires Very common. Tire

Fewer parts simplifies tire installation, reduced service time (required for careful matching of wheel and rim components) which reduces cost. Disc Wheel & Valve Stem Off-road Tires: Tread Breakers Off-road tires, either tube or tubeless, are Inner Tube designed to withstand heavy loads and shocks during operation.. Cord Side Body Walls Breakers may be made Flap of shredded steel for Rim Assembly added puncture protection and strength. Tube Type Tires Off-road Tires: Tread Breakers Off-road tires may Cord Body travel at relatively low speeds as Inner compared to an Bead Flange on-road tire, but their cargo weight is Side Rim Walls enormous.. Bead Outer O-ring Seat Flange Seal Band Tube Type Tires Off-road Tires

Caterpillar 797 truck carries 360 tons of payload plus the weight of the truck, for a total of about 615 tons on 6 tires. Off-road Tires

Directional tires (usually identified by direction of rotation arrow) are often used for better traction as well as their self cleaning tread ability.. Tires for motor grader application may have the same tread design for steering and traction.

Front tires treads may be mounted in the opposite direction to the rear, for steering stability. Solid Type Tires Some equipment may use solid type tires, where ride quality is not as important as load carrying capacity. Tire Tread Design

Rib Block Design Design

On-highway steering and trailer axles usually use the rib design, while most driving axles use the block design, because of its better traction ability.. Tire Tread Design

Tread design is basically for traction under different conditions, such as rain, snow and mud etc..

With new technology in tire design, compound mixtures and tread designs are becoming very specialized, especially in the automotive area, but is also spinning off into the on-highway heavy duty truck area. Tire Construction Two types of tire construction:

1. Bias Ply Tire

2. Radial Tire Bias Ply Tire: Have internal plies or cords overlapping at an angle, which makes for a strong but stiff tire.

The number of plies or cords give the tire its load carrying capacity. Cords

The plies or cords are made of rayon, nylon or polyester, the casing or body is made of natural or synthetic rubber and a bead of steel cable. Bias Ply Tire: The ply arrangement is the same in the sidewall as well as the tread area.

Thickness of plies in the Bead sidewall causes friction Side movement within the Wall plies, which builds up heat, eventually resulting Plies in tire failure.

Tread Bias Ply Tire: The ply arrangement is the same in the sidewall as well as the tread area.

Thickness of plies in the Bead sidewall causes friction Side movement within the Wall plies, which builds up heat, eventually resulting Plies in tire failure.

Tread Bias Ply Tire: The stiffness of a bias ply allows for little or no sidewall flexing.

This lack of flexing may cause the loss of tread contact with the road causing instability and loss of traction.

Bias ply tires are best suited for low speed and lower load operation. Tire Construction Radial Ply Tire: Reinforcing Belts Radial ply tires use steel in the body cords (plies) and steel reinforcing belts..

The plies are laid at 90° to the bead, for good flexibility..

Steel belts help to protect the tire from road hazards. Tire Casing Radial Ply Tire: Advantages:

Minimum movement between the plies generates less heat. Bead The flexibility in the Plies sidewall of the tire also allows for better Flexibility traction and control.

Belts Tread Radial Ply Tire: Advantages:

Less rolling resistance increases fuel economy. Reduces shock loads, resulting in less wear on steering components and enhances ride quality.

Higher speed and load capability.

Less repair costs due to puncture resistance. Tire Sizing

Tire size 10.00R20

10.00 is the Section Width of the tire in inches..

20 is the rim diameter in inches that the tire fits on. Tire Matching Single Tires:

Matching tires increases tire life. It reducing uneven loading and steering problems, such as pulling to one side. Tire Matching Tire manufactures allow a maximum difference in size on the same axle of:

Maximum Circumference Maximum Diameter Difference Difference

A B A B

A – B = ¾” (19.1 mm) A – B = ¼” (6.4 mm) Tire Matching Dual Tires:

When the same axle has a dual tire arrangement the sizing is also critical..

The specifications for dual tires is the same as for single tires.. Tire Matching Dual Tires: Straight Edge Remove weight off the tires to ensure accuracy..

String Gauge If vehicle load is evenly distributed, matching tires ensures equal tire loading and longevity. Tire Matching Dual Tires:

Exaggerated On a four wheel axle assembly, if a single tire is larger than the others (but still within allowable limits), install largest tire on outside wheel to compensates for crown of the road. Tire Care Under-inflation: Causes abnormal tire Under- deflection, heat build-up and inflation tire shoulder wear..

Over-inflation: Causes harsher ride, transmits more shock loads to steering Over- and suspension components, inflation and tire centre wear. Tire Care Proper Inflation:

Results in proper tire to road contact for traction, braking, safety and Proper even tire wear.. Inflation

Caution Ensure a clean and dry air supply for inflation, to prevent internal wheel and tire damage. Tire Care Tire Rotation: Extends tire life..

Washing tire will make inspection easier, and also removes dirt, oil, and grease, preventing rubber deterioration..

Follow manufacturers recommended pattern. Objective Three State the safety procedures required when handling tires and wheels. Safety Precautions Potential paths for explosive forces.

Release all air from the tire, before removing side ring, lock ring, or a tire assembly from a vehicle, for service work. Safety Precautions Release tire air pressure by the valve core to approximately 40 psi, then remove valve core. In cold temperatures, moist air may freeze the valve stem opening closed, ensure no air pressure by inserting a wire into the valve stem.

Disassemble wheel/rim assembly as per manufacturer’s instruction, using proper tools to prevent personal injury and damage. Safety Precautions

Sprung Side Ring

Cracks

Broken Side Ring Wheel Nut Damage Clean components and visually inspect tire, rim, wheel and mounting components for signs of overheating, cracks, distortion and damage. Safety Precautions

Following manufacturer’s instructions regarding matching parts, ensure use of proper pieces that match rim. Safety Precautions

Always use a safety cage.

Use a clip-on air chuck on an extended hose with a remote inflate/deflate mechanism when inflating a tire, in case deflation is necessary.

Visually inspect to ensure that the tire beads and side ring or lock ring are properly seated. Safety Rules Never add air to a tire that was run while flat, or at 80% or less of recommended air pressure..

It Must be disassembled and inspected for damage..

Never hammer or pry on any type of tire that is partially inflated..

Never assemble mismatched tires and wheel / rim assemblies. Safety Rules

Lubricate tire and rim assembly with rubber lubricant, and with no valve core in the valve’s stem, inflate tire to maximum of 40 psi pressure..

If tire bead does not seat, deflate tire .. unseat bead .. apply lubricant .. square up tire .. retry.. Safety Rules

Off-load inflated tires with care, damaged components may cause the assembly to fly apart. Safety Rules Valve Stem Rim 1. Loosenin g the 4. Valve stem bead. installation. 2. Forcing the bead into 5. Work the the rim lower bead onto the well. rim.

3. Prying the rim out of the tire. 6. Work the upper bead onto the rim. Safety Rules

Bead breaking equipment is easier and safer when servicing a rim attached to the machine..

In off-road applications the rim may have more components, so matching parts correctly is critical. Safety Rules When removing and installing tires, smooth clean tools prevent rim and tire damage..

Work carefully when installing side rings and lock rings.. Safety Rules

Cleanliness prevents abrasive materials entering the tire and reducing tire life..

Use lubricant when installing tire..

Always use a restraining device when removing the tire. Safety Rules Pry Bar Flanges Bead Seat Lock Ring Slot (Side Ring) Band Toe 5° Bead Seat Band, Taper Ring Rim Base Gutter Notch for Lock Ring Driver O-ring Gasket Lock Ring Driver Tubeless Valve Hole Locator – Demountable Rim Only

Cross section of a five piece rim assembly. Safety Rules

Occupational Health and Safety Regulations

General Hazard Requirements Document

Read it Objective Four Perform wheel removal, inspection and installation Axle Hub Mounting Outer Dead Axle: Wheel Wheel Nut Bearing Disc Wheel hubs are Wheel supported by two Wheel wheel bearings.. Stud Axle Spindle The wheel hub rotates Hub around a stationary Hub Brake spindle that is Cap Inner Drum attached to the axle.. Wheel Bearing Steering axles and trailer axles are usually dead axles. Live Axle Hub Mounting Outer Wheel Bearing Outer Wheel Inner Wheel Outer Wheel Nut Wheel Stud Axle Shaft Axle Housing Drive Axle Stud Brake Drum

Hub Inner Wheel Bearing

Live axles are usually drive axles.. Live Axle Hub Mounting The hub is supported by two wheel bearings that rotate on the axle housing..

Hub Spindle

Axle Axle Shaft Housing

Outer Wheel Inner Wheel Bearing Bearing

The hub is driven by the axle shaft, through the center of the axle housing. Axle Hub Removal

A removable brake drum style of axle hub, with drum pilot and wheel pilot notches.. Pilot Pad

Wear proper breathing mask, the brake dust Drum may contain asbestos. Wheel Pilot Pilot Hub and bearings must be kept free of dust, dirt, and lubricated properly when installing. Axle Hub Removal Dowel Wedge Nut Axle Shaft Flange

Flat Washer Clearance Most axle shafts are retained by split tapered dowel wedges, Do Not remove nuts until dowel wedges are loose. Axle Hub Removal 1. To remove the axle shaft, first loosen all axle shaft nuts only a few turns..

Axle Shaft Nuts

2. Strike the center of the axle shaft with a large hammer and drift to loosen the tapered dowels, then remove nuts, dowels and axle. Axle Hub Inspection

Hub cleanliness Stud Nut is essential for component Brake Drum longevity.. Mounting Studs

Inspect all parts Axle Shaft for serviceability.. Mounting Studs

Install lubricated bearing assembly and seal in the hub, to prepare for installation onto the axle housing spindle. Axle Hub Inspection Clean all spindle mounted parts with non-petroleum based product..

Shiny spots on spindle’s bearing mounting surface may be caused by bearing creep..

Normally bearing creep allows the bearing’s inner ring to slowly turn on the spindle to prevent spot loading of the bearing. Axle Hub Inspection Spalling damage.

Clean and inspect bearings for spalling before reusing. Axle Hub Inspection The ends of the studs may be stamped with “L” or “R”, to designate left or right hand thread.

Crack damage may be caused by improper stud installation.

Crack Axle Hub Inspection Replace When wheel studs break in service, its usually because of over tightening.

Always replace the studs on either side of the broken Serrations stud as well.

When replacing wheel studs, ensure proper length, style and thread direction. Clipped Head Axle Hub Installation Using proper steel Seal tools, install lubricated Bearing bearing cup, and seal Centering in the right direction. Tool

Do not use brass tools, Outrunner they chip easily and Adapter Plate contaminate the assembly process. Outrunner Handle Axle Hub Installation

Hub retaining devices such as adjustment nuts and locking devices should be properly set. Axle Hub Installation Fill the hub cavity with recommended lubricant, before axle installation.

Some hub assemblies are equipped with see through sight glass, for lubrication oil level identification. Axle Hub Installation

On flange style wheel nuts, use two drops of oil between the flange and the hex.. Oil On a dual wheel assembly, ensure spacer is of the correct width for the application. Stud Rim Spacer Clamp Axle Hub Installation Nut Assembly Typical wheel mounting Flange arrangement.

Single (front)

Nut Assembly Flange Dual (rear) Axle Hub Installation Typical Wheel Tightening Patterns 1 1 6 9 2 3 4 4 7 3 4 6 5 3 8 1 5 2 5 2 10 Torque in three steps, 1/3, 2/3, and full torque, according to manufacture’s torque specification..

Recheck torqued wheel nuts after 100 – 150 km. Objective Five Explain wheel balancing. Wheel Balancing Wheel balancing is required to maximize tire life and to eliminate unnecessary vibrations..

Two main types of wheel balance problems can exist.. 1. Static Unbalance.. 2. Dynamic Unbalance..

Wheel balancing is accomplished by using a computerized machine.. Few shops have hand type balancers. Static Balance Problems Bounce: Is a heavy spot in the center of the tire which causes the Heavy wheel to bounce, tramp or Spot hop.. Centreline of Static unbalance may cause Spindle localized tire tread wear, shock absorber failure, poor braking and steering, because of loss of tire to road contact. Dynamic Balance Problems Shimmy: Is a heavy spot off center of the tread, which causes a Heavy shimmy or wiggle. Spot

Dynamic unbalance may Centreline of cause tire wear (scuffing), Spindle steering tie rod component failure, as well as steering problems. Runout Radial Runout Lateral Runout Check Wheel Check Wheel Lateral Radial Runout Runout

Check Total Check Radial Runout Total Lateral Runout

Using a roller tip dial indicator, check for total radial and lateral runout. Static Tire Balancing Light Side (bubble not centered) Balancer Cone

Disc Tire Wheel Centre Side View (exaggerated) Top View

Cone Type Static Wheel Balancer Static Tire Balancing Corrective Weights: Add Balance Weights Here

Heavy Spot At 180° opposite the heavy spot, place one half of the required weight on each side of the rim, Dynamic Tire Balancing Can be done on or off the vehicle depending on type of wheel balancer device used.

Cleanliness of the wheel and tire assembly is critical for accurate balancing.

If balancing larger, lug type tire assemblies, balance one side first, then the other side. May be more accurate and less time consuming. Dynamic Tire Balancing Corrective Weights: Add Balance Weights Here

Heavy Spot

Always recheck tire balance after adding recommended balance weight. Objective Six Diagnose wheel and tire faults. Introduction Leading End

Front Rear Axle Axle

Trailing End

Rear axle housing out of alignment can cause tire scuffing and pulling to one side. Tire Damage Tire damage is most often caused by human error, such as overloading, excessive speeds and operating off-road..

Tire damage may also be caused by:

ℴ Suspension damage..

ℴ Incorrect alignment settings..

ℴ Improper matching of tires..

ℴ Road hazards (rocks, nails, pot holes, etc). Tire Damage Tire damage may also be caused by:

Under-inflation Over-inflation Tire Damage Feathered Edge

A worn tie rod generally causes a feathered edge. (Affects Toe) Tire Damage Damaged Bias Ply Punctures can affect tires differently depending on their construction design.

Sizing tires correctly on each axle, ensures even Damaged loading of the individual Radial tires. Wheel / Rim Damage

Chording –Flat spot on a wheel caused by heavy loads and impacts, which reduces the air retaining ability of the wheel or rim. THE END