CLUTCH
GEARBOX
DRIVESHAFTS
263
SPEEDOMETER
ALL TYPES
An E.E.C. decree of
25 June 1976
, regulates the speed displayed by the speedmeter in relation to the actual speed travelled.
This decree stipulates :
- The speed indicated by a speedometer must never be lower than the actual vehicle speed.
- Between the speed displayed
«SD»
and the speed travelled
«ST»
, there must always be the following relationship :
ST < SD < 1.10 ST + 4 Kph
Example : For an actual speed of
100 Kph
the speed displayed by the speedometer may be between
100
and
114 Kph
.
The speed indicated by the speedometer may be influenced by :
- The speedometer.
- The tyres fitted to the vehicle.
- The final drive ratio.
- The speedometer drive ratio.
Any of these components can be checked without removing them from the vehicle. (See information note
N° 78-85 TT of 19 October 1978.
NOTE :
Before replacing the speedometer, check the conformity of the following points :
- The tyres fitted to the vehicle.
- The gearbox final drive ratio.
- The speedometer drive ratio.
