Periodic Maintenance Procedures
Wheel/Tire Damage Inspection
Remove any imbedded stones [A] or other foreign parti-
cles [B] from tread.
Visually inspect the tire for cracks and cuts, and replace
the tire if necessary. Swelling or high spots indicate inter-
nal damage, requiring tire replacement.
Visually inspect the wheel for cracks, cuts and dents dam-
If any damage is found, replace the wheel.
Tire Tread Wear, Abnormal Wear Inspection
As the tire tread wears down, the tire becomes more sus-
ceptible to puncture and failure. An accepted estimate is
that 90% of all tire failures occur during the last 10% of tread
life (90% worn). So it is false economy and unsafe to use
the tires until they are bald.
Measure the tread depth at the center of the tread with a
depth gauge [A]. Since the tire may wear unevenly, take
measurement at several places.
4.5 mm (0.18 in.)
6.4 mm (0.25 in.)
1 mm (0.04 in.)
(AT, CH, DE) 1.6 mm (0.06 in.)
2 mm (0.08 in.)
(Up to 130 km/h (80 mph))
3 mm (0.12 in.)
(Over 130 km/h (80 mph))
If any measurement is less than the service limit, replace
the tire (see Tire Removal/Installation in the Wheels/Tires
Some replacement tires may adversely affect han-
dling and cause an accident resulting in serious in-
jury or death. To ensure proper handling and sta-
bility, use only the recommended standard tires for
replacement, inflated to the standard pressure.
Most countries may have their own regulations a mini-
mum tire tread depth: be sure to follow them.
Check and balance the wheel when a tire is replaced
with a new one.
PERIODIC MAINTENANCE 2-27