Cotal (English)

Cotal (English)

ERK automobiles specializes in Cotal gearboxes and has many years of experience.

Operation of Cotal gearbox

A Cotal gearbox is four speed and electrically operated. It is operated by means of magnetic coils. A Cotal gearbox consists of two zones. Each zone consists of a disk comprising magnetic coils which is either rotating or stays fixed. In between them is a planetary gear system. The planetary gear system is connected to the rear axle. Gear change is obtained by operating the gear handle. According to a specific pattern the magnetic coils are energized allowing the planetary gear system to set a higher or lower gear. Depending on the chosen gear the planetary system rotates or stays fixed as a result of being attracted by the rotating or the stationary magnetic coil disk.

Cotal gearboxes exist in various types and are labeled with the letters MK followed by a number representing the number of mkg torque. Most common are:

  • MK12
  • MK15
  • MK20
  • MK25
  • MK30
  • MK33
  • MK35
  • MK38

Cotal gearboxes can be found in:

  • Delahaye
  • Delage
  • Hotchkiss
  • Salmson
  • Bugatti
  • Ford Comete
  • Peugeot
  • Citroen

Most common complaints are:

  • Skidding in the gear
  • The gear does not engage
  • Screeching gear box

This may indicate:

  • Worn magnetic coils, gears or ball bearings
  • Defective oil pump
  • Defective solenoids

Cotal defective gearboxes are professionally restored by ERK automobiles. At each revision the ball bearings and oil pump will be replaced. Planetary gears with too much slack get new oversized pins and needle bearings. The surfaces of the magnetic coils are treated. A defective coil can be rewound so that the Cotal gearbox operates again as it should.