General safety requirements - Wheels, Tyres and Hubs

Objective:

To ensure that road wheels and tyres are of a suitable type and condition and that they provide the necessary load
carrying capacity, speed rating and control of the vehicle.

1. Check wheels and rims :

a) Any wheel or rim:

• is loose
• is cracked
• is buckled
• has pieces of casting missing
• has elongated stud holes
• has weld repairs not in accordance with relevant
industry practice.

b) Any wheel contacts unrelated vehicle components
at any point through its full range of travel.

c) Spindle nuts and washers are missing, cracked,
stripped or broken.

d) Spiders have cracks across a spoke, hub or web area.

e) Wheels are not compatible with hubs.

f) Excessive end-play in hubs.

g) Wheels rotate freely.

h) Leakage hubs seals.

2. Check wheel/rim fasteners :

a) Wheel nuts and bolts do not have a thread
engagement length at least equal to the thread
diameter (except where specified by the vehicle
manufacturer), or the fitting of the wheel nut does
not match the taper of the wheel stud hole.

b) Check that any hub shouldn't missing, cracked, stripped or broken wheel mounting nuts, studs or bolts.

c) Spacer plates are used between hub and wheels,
except where fitted by the vehicle manufacturer.

d) Any item that is fitted to the tyre, rim or wheel (other than tyre pressure monitoring or inflation) which is not technically essential to the vehicle, protrudes from any part of the vehicle so that it is likely to increase the risk of bodily injury to any person.

3. Check retaining rings :

a) Lock or side rings shouldn't be incorrectly seated, sprung,
mismatched, bent, broken or cracked.

4. Check tyres :

a) Check tyre air inflation at frequent intervals or in every trips.

b) Tires (including sideways) should not have deep cuts, chunning, Bumps, protrusions, exposed cords or other signs of Body failure.

c) Check tyre wear pattern in every trip, and go for wheel alignment diagnosis,if uneven or more tyre wear seen. 

d) The vehicle should be fitted with a OEM front wheel (i.e. rim and tyre) or recommended with OEM standards.

e)Any tyre should be of a type constructed for unrestricted road use.

f) The speed rating of all tyres should be of at least 100km/h or the vehicle’s top speed, whichever is the lesser, unless a lower rating has been specified by the manufacturer.

g) The tyres on an axle should have same carcass construction (e.g. cross ply, radial ply or bias belted).

h) Dual tires should not contact each other.

i) notice that Any tyre on a vehicle should not contact the body, chassis, frame, braking, steering and suspension components at any point through its full range of travel.

j) Tyres should always be compatible with the rim to which they are fitted.

©️ 2019 A2s Truckinfo.

Effects of worn front axle suspension components!

Worn front end suspension components = Unusual Tyre wear = Higher fuel consumption.

In this post you will get to know how front end suspension components affect the following parameters!

1. Cause improper front end alignment.
2. Increase tyre wear.
3. Reduce fuel economy and increase operational costs.

Normal Tyre Conditions: 

Gradual tyre wear is normal; flat and even tyre wear is a sign of correct alignment, tyre balance, and proper inflation.

Alignment Purpose:

Alignment compensates for slight normal front suspension tolerance and component wear in king pins, bushings, tire rod ends, steering gear, and springs that sag.

Lubrication:

Regular lubrication prevents or defers wear to these components. Not only it's important to lubricate the front suspension at correct intervals, but it is also very important to use the correct type of lubricant.

Misalignment Indicators:

Tyres with even the slightest edge wear, cupping, or spotty wear are exhibiting signs of misalignment. This misalignment may be a result of either poor alignment settings or worn parts that create a misaligned front suspension.

Tyre Wear:

Heavy, spotty, cupped or irregular tyre wear are signs of components of king pins, bushings, tie rod ends, steering gear, pitman arms, idler arm, shock leakage, or wheel bearings that are out of specification. Below Figure, identify each type tire wear problem.

Energy Savings:

Tyre scrub, a lateral force that pushes the tyre sideways, adds to the rolling resistance of the vehicle. As a result, more energy is required to move the vehicle in its intended path of travel. Tyres are constructed from petroleum stock; therefore, if tyres wear out prematurely, natural resources are wasted.

Balance:

Tyre and wheel balance compensates for static and dynamic unbalance of wheels and tyres. Unbalanced tyres bounce and lose contact with the road. The "heavy side" of the tyre comes in contact with the road and small excessive amounts of the rubber are rubbed off.

Improper Inflation:

Improper inflation, too low or too high, may also result in excessive tyre wear. Underinflating wears out the edges of the tyre and adds to tyre drag. Fuel is wasted due to increased drag. Overinflation wears the tyre in the center. The illustrations below portray road contact and wear patterns when tyres are:

Many heavy truck operators and technicians ignore minor suspension and tyre wear problems. Traditionally, tyre cost has been insignificant to the overall cost of operation. Since the trucking industry has become increasingly more competitive, small incremental costs can begin to reduce an operator's profit margin. Tyre scrub results not only in worn tyres, but also in decreased fuel economy. Technicians must demonstrate to customers superior knowledge of methods that can lower operating costs.

©️ 2019 A2s Truckinfo.

Importance of Rear Axle Alignment on heavy Trucks

A properly aligned front end has long been established as a necessity for long tyre life, handling ease, and driving safety, as well as a factor in achieving optimum fuel economy

However, until recently, little attention has been focused on the alignment of the rear axle. A misaligned rear axle may result in:

a) Reduced tyre life;
b) Difficulty in driving;
c) An unsafe vehicle;
d)Less than optimum fuel economy.

According to our studies, "It has proven that 80% of  Multiaxle trucks are operating misaligned, and over 90% of the trucks they pull have serious alignment problems." The majority look like those in Figure 2.

A misaligned rear axle causes excessive tyre-to-road drag and creates undesirable lateral forces.

Figure 1 illustrates correct tandem axle alignment.
Figure 2 illustrates some possible axle alignment conditions.

Even new trucks need rear axle alignment. 

Studies also cite that up to 70% of new vehicles need some form of rear axle alignment. In a study of around 1500 trucks, those with proper rear axle alignment vehicle having 10-20% more tyre life and having fuel saving upto 5%.

According to recent studies conducted, Additional real axle drag and scrub contributes to even more fuel loss and decrease in tyre life. "Sixty percent of steering axle tyre wear is caused by drive axle misalignment."

All heavy trucks and trailer units should have their rear axle alignment checked and adjusted periodically or when any abnormal tyre wear appears. Rear axle alignment should be checked after any collision repair. Minor shifts in the frame-to-suspension mounts may cause significant shifts in both front and rear axle alignments. To align the front axle will only fix half the problem.

Below figure illustrates various effects on fuel consumption. Drag and tyre rolling resistance accounts for the single largest segment of fuel consumption - 42.2%. Any action taken to reduce rolling resistance, such as proper alignment, can and will reduce fuel consumption.

It is possible for a given truck to have reciprocal rear axle misalignment conditions. If this were the case, it may not exhibit any poor driving characteristics. However, tyres will still wear and fuel economy will be decreased.

Tyre Wear usual suspects:

Rear axles usually have little or no camber and toe requirements.

Heavy trucks rear axles use no caster alignment correction.



©️ 2019 A2s Truckinfo.

Wheel Alignment Angles

To correct the Wheel alignment, a technician will adjust the angles of the wheels so they’re set exactly to the vehicle manufacturer’s specifications.

The ways vehicle alignment is measured  : 

There are several ways that alignment (sometimes called ‘tracking’) is measured and corrected. These angles are known as the caster, camber, Kingpin inclination, toe and thrust:


Caster : compares the steering axis to the vertical axis, when the vehicle wheel is viewed from the side.

Camber : measures the vertical tilt of the wheels, when the vehicle is viewed from the front.

Kingpin  Inclination : It is also known as Steering Axis Inclination(SAI) and is the imaginary line drawn through the kingpin as viewed from the front.

The purpose of SAI is to provide an upper suspension pivot location that causes the spindle to travel in an arc when turning, which tends to raise the vehicle

Toe : measures whether the front of a pair of wheels turns in or out, viewed from the front.

Thrust : the imaginary line drawn perpendicular to the rear axle's centreline.

Signs you need wheel alignment : 

It’s not always clear whether a problem points to wheel misalignment or another issue with a vehicle. Here are the main vehicle alignment symptoms to watch out for:

Vehicle pulls to the left or right :

This is often the first sign that drivers notice. Very slight pulling or drifting to the side is normal, as roads aren’t perfectly flat and there will be some crowning in the road surface. But driving straight should feel easy, without much need for steering.

Steering Wheel Wobbles :

If you can feel vibrations in your hands, there can be a range of reasons. It may be a symptom of bad wheel alignment, but not necessarily. Steering wheel Wobbles may also indicate worn parts or tyre imbalance.

Abnormal or rapid tyre wear :

The wear on your tyres is a good clue to the general health of your vehicle. Unusual wear, such as focused on the inside or outside, will give a trained technician a picture of how the weight is distributed through the vehicle. Perhaps there’s a tilt at the top of the tyre or excessive wear on the outside edge, showing that vehicle realignment is needed. You can see a diagram of tyre wear patterns, and probable causes.

If you’ve tuned into any of these signs, it’s time to have your vehicle alignment checked.

What causes vehicle alignment issues?

Alignment problems will occur naturally over time with the ordinary ‘wear and tear’ of vehicle parts and as a result of aging. They can also be caused by a particular event, like impact with a nasty pothole or bang up a high curb. It’s common to have an alignment problem after an accident, and if you have the suspension raised or lowered to adjust the ride height, the wheels will need the vehicle realigned to make sure it fits the vehicle maker’s specifications.


Checking out an alignment problem :

Wheel alignment issues won’t go away. If you ignore them or delay a visit to a garage, you may experience more problems and face bigger, unnecessary costs. When camber and toe (alignment) specifications drift outside the manufacturer’s limit, it can quickly lead to:

• Premature wear of tyres and steering and suspension parts – which is expensive
• Undue stress on the whole suspension system – which is damaging
• Poor handling and road holding – which is dangerous

Note : For heavy commercial vehicle, Only Toe and Thrust can be adjusted through wheel alignment service, other angles are fixed but that angles can also be adjusted by different mechanical works.

©️ 2019 A2s Truckinfo.

Myth of Wheel Alignment

Wheel alignment requires only when tyre wear taking place or when some suspension/steering repair work would be done i.e. it's not a regular or interval alignment service .

Which is extremely wrong concept, The reality is that wheel alignment is an regular basis service that is very much requires for your vehicles performance-To increase tyre life, fuel savings and to increase the related(suspension/steering) parts & components life of your vehicle.

Ultimately it's a cost of tyre that costs you more.

©️ 2019 A2s Truckinfo.

Why need Wheel Alignment ?

We need a wheel alignment service for vehicles because it is directly connected to the overall performance of the vehicle as your vehicle performance is primarily measured in terms of fuel economy, driveline efficiency, and tyre life. And the wheel alignment service for your vehicle lets you control the tyres life and fuel consumption. We will discuss further how this happens.

https://www.instamojo.com/shubh0453/wheel-alignment-case-study-eu/

What is Wheel Alignment?

• Wheel alignment is a process of repositioning the suspension and steering parts and components for normal wear and effects of replacing parts.

• Correct wheel alignment should be checked after parts replacement and periodically during the life of the vehicle.

• Technically, Wheel alignment is a series of angles that position the tyres in relation of the vehicle's body, road, and the other tires.

• A properly aligned vehicle is one in which all wheels are aimed in the same direction.

How can Wheel Alignment benefits your operations?

As we can see that in over the road transportation, the main operating expenses in our vehicle are fuel and tyres. Both  are typically perceived as hard to control.
periodically checking of wheel alignment is the most effective way to control tyre costs and can optimise fuel consumption as well.
By focusing on this two parameters (i.e. fuel and tyres)we can achieve lot of savings.
Problems created by misalignment:

• Excessive tyre wear

• Increased fuel consumption caused by increased rolling resistance 

• Increased expensive auto repair 

• Unsafe vehicle handling characteristics 

• Premature suspension component wear

• Driver fatigue and driver retention 

©️ 2019 A2s Truckinfo.

Samsung Galaxy M30 (Gradation Blue, 4GB RAM, Super AMOLED Display, 64GB Storage, 5000mAH Battery)