News

Citroën Diravi rack and pinion

The Citroën Diravi rack and pinion we sell for quite some time now. Recently, we have revisited one again for a satisfied customer. It is a very complex rack and pinion and, at the time it was designed, very advanced and progressive. This rack and pinion can be classified as the first variable assisted power steering wherein the degree of power steering  being speed dependent.

Diravi is the name Citroën has given to its variable assisted power steering, which was designed in the early 70's. This was the first commercially available variable assisted power steering and has been used in several cars, such as Citroën SM, Citroën CX and Citroën XM, but also in the Maserati Quattroporte II and Maserati Khamsin.

How does as Citroën Diravi rack and pinion works

The name, Diravi, is an acronym for Direction à rappel asservi what literally means power steering with controlled return. The steering wheel is connected to the rotary valve which consists of two hydraulic actuator controllers; which are completely mechanical. One of the hydraulic actuator controller is responsible for the hydraulic pressure at certain steering situations and the other is responsible for the steering force that depends on the travelling speed of the car and steering angle. The piston of the rack and pinion is not directly mechanically connected to the steering wheel in normal operation. The wheel rotation is purely controlled by the hydraulic actuator controllers by hydraulic pressure.

Citroën Diravi rack and pinion in components
Citroën Diravi rack and pinion

Rocker shaft repair

We often see that the outgoing rocker shaft (where the pitman arm is connected) is corroded by age. We can fix this!

Axis repair
Mercedes W109 rack and pinion