When Should Commercial Truck Tyres Be Replaced?

1. Tread depth

Tread depth is the most common reason to replace a truck tyre. Measure it with a tread depth gauge in the main grooves, at several points around the tyre and across its width. Do not measure on the tread wear indicator bars.

• Wear indicators (TWI): small raised bars in the bottom of the grooves. When the tread is level with them, the tyre is at its legal minimum and must be replaced.
• Steer tyres: many fleets replace steer tyres well before the indicators, then move them to a trailer or drive position if fleet policy allows. Grip and stability on the front axle matter most.
• Drive tyres: lose traction in wet conditions as the blocks wear down, so watch them closely before the rainy season.
• Trailer tyres: wear slowly but are prone to scrubbing and damage, so check them as often as the rest.

Pulling tyres while the casing is still sound also protects it, which matters if you retread.

2. Damage you can see

Take the tyre off and have it inspected if you find any of these:

3. Uneven wear

Irregular wear shortens tyre life and often points to a fault on the truck. Replace the tyre if the wear is severe, and fix the cause before fitting a new one:

• Both shoulders worn: underinflation or overloading.
• Centre worn: overinflation.
• One shoulder worn: wheel alignment, often on the steer axle.
• Cupping or flat spots: worn suspension, shock absorbers or wheel bearings, or wheels out of balance.
• One dual worn more than its partner: different pressures or mismatched tyres.

4. Pressure loss and vibration

A tyre that keeps losing pressure may have a slow puncture, a leaking valve, a damaged bead or a cracked rim. A truck that vibrates at speed may have a tyre with internal separation. Find the cause. If it is the tyre, replace it.

5. Age

Rubber ages even when the tread looks good, especially in hot sun. Low-mileage trucks, spares and trailers that stand for long periods are most at risk. Check the date code on the sidewall: a four-digit number such as 1224 means week 12 of 2024.

Many fleets inspect tyres closely once they pass five years and remove them by around ten years from manufacture, whatever the tread depth. Follow your tyre maker's advice and your fleet policy, and never fit an old spare to the steer axle.

A simple inspection routine

1. Daily walk-round: look for low tyres, cuts, bulges and stones between duals.
2. Weekly: check pressures cold and measure tread on the steer axle.
3. Monthly or at service: measure all tread depths, record them, and check alignment and wear patterns.
4. After a hard knock: such as a pothole, kerb or rock strike, inspect the tyre and rim before continuing.

Write down readings for each tyre and position. You will see which tyres are due soon and can plan replacements before they become breakdowns.

Plan replacements, do not wait for failures

A tyre that fails on the road costs much more than the tyre: recovery, lost delivery time, damage to the truck and, on a steer axle, the risk of an accident. Fleets that replace on schedule buy tyres at a planned time and price, and keep trucks earning. When you replace:

• Fit new tyres in matched pairs on duals and across each axle.
• Put the best tyres on the steer axle.
• Choose the right pattern for the position. See best truck tyres for long-distance haulage.
• Check rims for damage and fit new valves.

Replacement tyres from Proclassic

Proclassic Tyres supplies steer, drive and trailer tyres in all the main truck sizes, including 315/80R22.5, 385/65R22.5, 295/80R22.5, 12R22.5, 13R22.5 and 1200R20, with fitment and pressure checks at our branches and delivery across Zimbabwe. Send us the sizes and positions you need to replace and we will confirm stock and price on WhatsApp. See all sizes on our truck tyres page.