Wheels/Tires - Road Force Measurement Equipment
Shudder
A low-frequency vibration that is felt through the steering wheel or seat during light brake application.
Slap
A resonance from flat surfaces, such as safety belt webbing or door trim panels.
Slip Yoke/Slip Spline
The driveshaft coupling that allows length changes to occur while the suspension articulates and while the driveshaft rotates.
Squeak
A high-pitched transient sound, similar to rubbing fingers against a clean window.
Squeal
A long-duration, high-pitched noise.
Static Balance
The equal distribution of weight around the wheel. Statically unbalanced wheel and tire assemblies can cause a bouncing action called wheel tramp. This
condition will eventually cause uneven tire wear.
Tap
A light, rhythmic, or intermittent hammering sound, similar to tapping a pencil on a table edge.
Thump
A dull beat caused by two items striking together.
Tick
A rhythmic tap, similar to a clock noise.
Tip-In Moan
A light moaning noise heard during light vehicle acceleration, usually between 40-100 km/h (25-65 mph).
TIR
Total indicated run out
Tire Deflection
The change in tire diameter in the area where the tire contacts the ground.
Tire Flat Spots
A condition commonly caused by letting the vehicle stand while the tires cool off. This condition can be corrected by driving the vehicle until the tires
are warm. Also, irregular tire wear patterns in the tire tread resulting from wheel-locked skids.
