There sure is a whirlwind of change blowing in the trucking and commercial tire industries.
A tornado is building as the economy improves and fleets get back on the highways. Capacity is shrinking, rates are firming and new truck and trailer sales are growing. Also, every puff of hot air coming out of Washington, D.C., is causing a cyclone of new regulations that are blowing across the country and are affecting commercial carriers, truckers—and ultimately you if you have any dealings with customers.
All of these escalating gale force winds are changing the way we all do business. You'll look back on this time in years to come and marvel that you lived through it without having a house fall on you.
One of the changes I know is happening is that more and more fleets are asking their tire dealers to do more to help them stay safe and profitable. They are looking to them to take on more responsibility for ensuring their tires are well maintained and meet safety regulations so their federal safety rating remains “Continue to Operate” rather than “Unfit,” shutting them down and putting them out of business.
This means that more trucking fleets will be outsourcing some of their on-vehicle tire inspections to commercial tire dealerships since, up to now, some of them haven't been doing such a great job on their own. They may contract with your company to inspect their vehicles on the weekends or in the evenings when the equipment has returned to the fleet's yard.
That means checking their tires for possible replacement or repair if they have low tread depths, cuts or snags, punctures or are flat. Wheels with cracks, broken studs, etc. can be replaced as well.
While you're at it, they'll want their tire air pressures adjusted as necessary.
Do your technicians know how to do an on-vehicle tire and wheel assembly inspection correctly and efficiently? It's basic stuff but it doesn't hurt to review it.
Inspection basics
The procedure for inspecting tires and wheels on a tractor-trailer unit is fairly simple.
However, it does take some practice to develop “good eyes” that are trained to recognize all the signs of problems that may be evident. It is also good to develop a routine to follow so that you get in the habit of doing these inspections the same way every time. This will prevent you from missing or forgetting to perform a part of the inspection.
Before beginning an on-vehicle tire/wheel inspection, here are some tools that you should carry with you:
* A calibrated air gauge;
* A tread depth gauge;
* A tire probe;
* Valve caps;
* Tire chalk/crayon;
* A pair of pliers;
* A 3/8-inch bulge gauge; and
*Clipboard with paper and pen/pencil.
To begin your inspection, start on the front driver's side of the truck at the left front steer tire and then work your way back around the vehicle to the right side, ending at the right front steer tire. (I like to start at the left side of the vehicle since the vehicle unit number is usually on that side and I can get the tractor mileage right off the bat if I need it, too.)
As you go around the vehicle, inspect the tires like this:
Bend down, stick your head under the vehicle to the left of the tire(s) and inspect the inside sidewalls of the tire(s) and their wheel(s)—three sidewalls for duals; both sidewalls of the inside tire and the inside sidewall of the outside tire.
Then look at the tread on the left side of the tire(s). Once this is done, check the tread on the top of the tire(s) as you move around to the right side of the tire(s). When you reach the right side of the tire(s), stick your head under the vehicle and inspect the inside sidewalls of the tire(s) and wheels and then the tread on the right side of the tire(s).
If you see any low spots, check them with a tread depth gauge. Move back in front of the axle end, squat and inspect the outside tire sidewall and take the pressures of the tires. While there, let your eyes circle and inspect the wheel, lug nuts and studs as well.
OK, that's the inspection process. Now what do you look for and what do you do if you find something wrong?
Tire conditions
Everyone talks about inspecting for “unserviceable tire conditions,” but do you know what they actually are? According to the Department of Transportation (DOT), no motor vehicle can be operated on any tire that has the following conditions:
1. Has body ply or belt material exposed in the tread or sidewall;
2. Has any tread or sidewall separation (indicated by bumps, bulges or knots);
3. Is flat or has an audible leak;
4. Has a cut that exposes ply or belt material;
5. Has a cold inflation pressure less than that being specified for the load being carried;
6. Has steer tires with tread depths of 4/32 inch or less;
7. All other tires with tread depths of 2/32 inch or less;
8. No bus can be operated with regrooved or retreaded tires on the steer axle; and
9. No truck or truck tractor can be operated with regrooved tires on the steer axle if the tires have a load carrying capacity equal to or greater than that of 8.25 x 20, 8 ply-rating tires.
The Commercial Vehicle Safety Alliance (CVSA), which comprises state inspectors who actually make roadside safety inspections, makes an exception to the No. 2 point above. Any tire with a bulge up to 3/8 inch due to a repair noted by a blue triangular patch on the sidewall is exempt from being put out-of-service and is OK to run.
The CVSA also has added another condition to its Out-Of-Service Criteria, stipulating that a tire is to be removed if it is so mounted or inflated that it comes in contact with any part of the vehicle. This includes any tire contacting its mate in a dual set.
Therefore, when inspecting tires look for cuts, snags, punctures, penetrating objects, cracks, weather checking deeper than 2/32 inch, separations, exposed or damaged cords, bumps, bulges, knots, etc. If any unserviceable tire condition is found, remove the tire. Check any repair-related bulge to make sure it does not exceed 3/8 inch with your bulge gauge. If it does, remove the tire for closer inspection.
Bulge gauges are used by placing the legs of the gauge on the sidewall of the tire. If there is space between the bulge and the gauge or the bulge just touches the gauge, the tire is serviceable. However, if the bulge prevents the legs of the gauge from touching the sidewall and the bulge exceeds 3/8 inch, the tire should be removed from the vehicle.
Also ensure that improper tires and tire sizes are not mixed on the same axle, such as bias ply with radial tires or low-profile tires with standard-profile tires. Remove tires that don't meet the fleet's maintenance policies or that have unserviceable conditions.
If tires are found that have been penetrated by objects, remove those objects with your pliers. Check for leaks by probing and applying water if needed. If the tire leaks, it must be removed for repair. If no leak is caused, the tire can remain in service.
If tires touch parts of the vehicle—such as broken spring hangers, bent mud flap brackets, broken trailer flooring or wheel wells—the vehicle must be repaired before it can be placed back into service. And if the damage to the tire is severe, the tire should be replaced as well. Make a note on your clipboard and be sure to advise your fleet customer that this vehicle has this equipment problem and is not roadworthy.
Tread conditions
Thoroughly check the tread for flat spots and use the tread depth gauge to measure the remaining tread. Always measure the tread depth of all the tires on the vehicle at the lowest spot of a major tread groove. Make sure you don't take the measurements on the treadwear indicators or wear bars. If the tread depth is below the fleet's specifications or DOT requirements of 4/32 inch on steer tires and 2/32 inch on all other tires, replace the tire.
Check for tires of a particular tread design in the wrong position and replace the tires according to the customer's policy.
If signs of cupping are evident on the tread, check the tire for mismatch. If you find dual tires that are mismatched by size and the fleet wants you to look for this problem as well, replace tires so that they match within 1/4-inch diameter (1/8 inch radius).
A crude down-and-dirty way of measuring mismatch is using 4/32-inch difference in tread depths between the two tires as a rough guide. (The use of a tire square is a more accurate way to measure mismatch, but most technicians don't carry one in their service trucks.)
In addition to dual tire mismatching, you will probably also find tires with wear patterns that can be caused by misalignment and loose or worn components. While these problems are not necessarily out-of-service conditions, they will rob the fleet of tread mileage and increase its tire costs. Therefore, make a note of these vehicles and advise the fleet that they need attention at their earliest opportunity.
Inflation pressure
Gauge each tire and while doing so check for valve caps, replacing missing or inoperable ones. Also inspect the condition of each valve stem. Any that are bent or damaged should be repaired or replaced as necessary.
If a tire's inflation pressure is within 20 percent of the fleet-specified air pressure, add air to correct the pressure. If the pressure of any tire is 20 percent or more below the fleet's desired inflation pressure, remove the tire for further inspection.
Do not reinflate the tire—it should be inspected to determine the cause of the leak. Remove any tire that is flat or has an air leak. If the pressure of a tire is above the fleet's targeted pressure and the tire is “cold,” bleed air from the tire to attain the correct inflation pressure. Never bleed air from “hot” tires since they will then be underinflated once they cool down.
Wheel conditions
Examine disc wheels for loose and missing lug nuts. Red rust streaks emanating from the nuts are usually a sign of looseness, as are variations in the number of stud threads that protrude beyond the nuts.
Variations in the number of visible stud threads also can be an indication of mismounted wheel-end components. Therefore, check for the correct torque and proper wheel alignment on the pilot pads of hub piloted wheel systems and then remove the rust streaks.
Replace lug nuts if missing and then retighten all the other nuts to the proper torque as well. The inner nuts on both sides of a broken inner cap nut also should be replaced.
Make sure that the correct nuts for the wheel system are being used, and inspect wheel bolt holes if you can for wear or damage.
Look for cracks in the washers of flanged cap nuts used in hub-piloted wheel systems. Replace the damaged nuts and tighten to the proper torque.
If you find a broken stud, replace it and the stud on each side of the broken one. If two or more studs are broken, replace all of them. If this type of work exceeds the fleet's expectations for your on-vehicle inspection service, make sure the fleet is informed of the vehicle's condition and knows this work must be done, or wheel-offs can occur.
Disc face exam
Look for cracks in the disc face, wallowed bolt holes and excessive corrosion that have reduced the metal thickness.
A general rule of thumb is that if the manufacturer stampings on the disc face are no longer legible, the wheel should be removed for further inspection.
Always replace any wheel that is cracked. Make sure you checked for cracks on both sides of the wheels and between duals when you had your head stuck under the vehicle.
If you find mismatched hand holes and are unable to check the pressure in the inside dual, reposition the dual wheels so that the valve stems are accessible and as close to 180 degrees apart as possible. Don't forget to check the pressure of the inside dual before you complete this work.
Also check to ensure that the wheel types are the same. They should all be stud-piloted or hub-piloted but they can never be mixed. Incorrect wheel types must be replaced.
Spoke wheels
Some customers may still use spoke wheels and demountable rims. Inspect those components for cracks in the spokes and mounting rings; bent flanges or rings; loose, missing or damaged nuts and clamps; bent, broken or stripped studs; distortions in the mounting rings and spacer bands; and incorrectly matched rim parts. Also check valve locators for slip damage and improper location.
If any of these conditions are found, the wheel and/or rim should be removed.
Sure, it seems like there's a lot involved in doing proper on-vehicle tire/wheel inspections. But they're a vital element of good truck tire maintenance and help ensure that safe vehicles operate on our highways.
By performing these inspections well, you can generate additional service revenue for your company and keep your fleet accounts in business and on the road. Do them poorly and the fleet will know—its safety rating suffers.
Ultimately, the forces that are gaining strength, taking the trucking industry by storm and changing how we all do business will be beneficial to everyone.