Mechanical odometers are usually maintenance-free and should be checked by a specialist approx. every 2 years.
In case of false indications or jerky running of the number rollers, avoid using excess oil or grease to make the odometer work again. Mechanical defects cannot be repaired in this way.
Read the operating instructions for the devices and avoid operating errors.
When changing the gearwheels, ensure good but not too tight engagement and rotate the gear before installing it in the device to check for ease of movement.
Stopping or jerky movements of the HALDA counter are usually due to wear of the gear wheel on the 10-position roller. This should then be replaced.
In oldtimers with the original speedometer cable, this may also be due to material fatigue of the speedometer cable core. This twists in itself and should be replaced.
Special attention should be paid to the HALDA - Twinmaster devices:
The Twinmaster with aluminum housing is not, like the newer HALDA - Twinmaster in plastic housing, equipped with 2 lateral adjusters, but only with one. Aluminium housing > 1 adjuster, plastic housing > 2 adjusters.
In order not to damage the unit and the drive, switch the Forward/Return button on both units to 0.
For the HALDA in the aluminum version with only 1 lateral adjuster, additionally set the drive button on the bottom right to the lower drive (turn to the left). This way you relieve the entire drive for the adjustment and avoid damages.
Electronic / partial electronic distance meters:
Electronic and partially electronic odometers are susceptible to false readings or failures due to voltage fluctuations and interference fields in the vehicle.
The following points should be observed during installation:
The sensor should not be installed in the immediate vicinity of magnetic fields or electrical systems.
These odometers should be connected directly to the battery if possible.
An intermediate voltage stabilizer is also helpful.
The ignition on the car should be radio interference suppressed.
If the connecting cables between sensor and odometer have to be extended, use cables with the same cross-section and resistance and ensure a good connection (soldered if possible).
Only if all these criteria are met can a reliable display of these devices be guaranteed.