If the diameter difference between dual rear tires exceeds the limit, the appropriate maintenance action is to:

• A. Continue operation
• B. Replace or re-seat tires to bring within tolerance
• C. Inflate one side to match
• D. Ignore and monitor

Answer: (B)

When dual rear tires show a diameter difference outside the allowed limit, the action needed is to bring the tires into tolerance before operation. A significant diameter mismatch means the two tires won’t rotate at the same rate, causing uneven loading, vibration, excessive heat, and uneven wear. This can stress the rims and create a high risk of tire failure or wheel damage in dual-tire setups. Re-seating can fix mounting or bead-seat issues and bring the diameters into spec; if re-seating cannot achieve the required tolerance, replacing one or both tires is necessary to restore a matched pair. Options like inflating one side to match or simply continuing to operate or ignoring the issue do not address the underlying mismatch and pose serious safety hazards.