Checking for tire wear patterns

Part 1. Preparation and safety

Objective

• Check tire for correct wear pattern and ensure there are no embedded foreign objects in the tread.

Personal safety

Whenever you perform a task in the workshop you must use personal protective clothing and equipment that is appropriate for the task and which conforms to your local safety regulations and policies. Among other items, this may include:

• Work clothing - such as coveralls and steel-capped footwear
• Eye protection - such as safety glasses and face masks
• Ear protection - such as earmuffs and earplugs
• Hand protection - such as rubber gloves and barrier cream
• Respiratory equipment - such as face masks and valved respirators

If you are not certain what is appropriate or required, ask your supervisor.

Safety check

• Make sure that you understand and observe all legislative and personal safety procedures when carrying out the following tasks. If you are unsure of what these are, ask your supervisor.

Points to note

• Some manufacturers supply an emergency rim assembly instead of a full-size spare. It is not intended for long-term use or high speed, but it must have adequate tread.

Part 2: Step-by-step instruction

1. Check for foreign objects and pressure
   Inspect the tires for embedded objects in treads and remove them, and look for signs of wear on all wheels, including the spare. Check the pressure in the tires.
2. Check tread wear depth
   Most tires have wear indicator bars incorporated into the tread pattern. Inspect the wear indicator bars. Tires should have at least one sixteenth of an inch, or two millimeters of tread remaining. The wear indicator bars are normally set at this depth. If the tread is worn down to that level or below, they are unserviceable and must be replaced.
3. Check tread wear pattern
   Check the wear patterns with the vehicle’s shop manual to indicate the types of wear that have occurred. Causes of uneven wear can include faulty shock absorbers, incorrect front alignment angles, and wheels out of balance. Uneven tread and bald spots can indicate over- or under-inflated tires and poor alignment.
4. Check tire for damage
   Inspect the sidewalls of the tires for signs of cracking from impacts with blunt objects. Carefully examine the tread area for separation. This is usually identified as bubbles under the tread area. Spin the wheel and see if it is running true. If it is wobbling as it rotates, report it to your supervisor.