VW Golf manuals

Volkswagen Golf Service & Repair Manual: Saw-tooth wear

Saw-tooth wear is a stepped wear pattern on the individual tread blocks → Fig. that can cause increased tyre noise. The saw tooth is caused by uneven deformation of the tread blocks in the tyre's contact patch. Saw-tooth wear is more pronounced on non-driven wheels than on driven wheels.
New tyres are more susceptible to saw-tooth wear because of the greater elasticity of the high tread blocks. As the tread depth decreases, the tread blocks become more rigid and the tendency to wear in a saw-tooth pattern decreases.
   
Appearance of saw tooth
A -  Tread block of a new tyre; seen in direction of motion -arrow 1-, tread blocks are equally high in front and back.
B -  Development of saw teeth; seen in the direction of rotation -arrow 1-, tread blocks are higher in front -arrow 2- than in back.
C -  Seen in the direction of rotation -arrow 1-, tread blocks show greater wear in the front section of the “saw tooth”-arrow 3-.
Pronounced saw-tooth wear can lead to customers complaining about tyre noise.
Pronounced saw-tooth wear occurs under the following conditions:
toe values are too high
tyre pressures are incorrect
tread is coarse and open
tyres are fitted on the non-driven axle
very fast cornering.
non-directional tyres
In the event of saw-tooth wear, the direction of rotation of the tyre must be reversed. If saw-tooth wear is especially pronounced and tyre noise has increased, interchange the tyres diagonally. This will reduce the saw-tooth effect.
On front-wheel-drive vehicles, this effect is intensified by the greater wear on the front axle.
Tyre noise will be somewhat louder immediately after the tyres have been interchanged but will return to a normal level after about 500…1000 km have been driven.
Directional tyres
In the event of increased saw-tooth wear on the rear tyres – in particular on front-wheel drive vehicles – interchange the front and rear tyres. In the event of increased saw-tooth wear on the outer edges of the tyres on one axle, turn both tyres around on their rims. The left-hand wheel must then be fitted on the right side of the vehicle and the right-hand wheel on the left side.
 

Saw-tooth wear

Wear behaviour of high-speed tyres

These tyres are designed for very high speeds. When developing these tyres, good grip in wet conditions is the main objective. The tread compositions do not have the same wear resistance as T and H tyres for lower speeds.
The life expectancy of high-speed tyres is therefore considerably lower in comparable conditions of use.
   
Factors influencing the service life of tyres
The following factors influence a tyre's service life to varying degrees. Driving style: Speed ...

Measuring tread depth
  Note The tread depth is measured in the main tread channels. Do not measure at the TWIs (Tread Wear Indicators). ...

Other materials:

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Matching wheels and tyres
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Repairing threaded connections
Special tools and workshop equipment required     VAG 1331   Note The use of penetrating fluid, contact spray or grease etc. is prohibited since the missing ad ...

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