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Technical reference page: 44

Frazier four wheel steering - retrofit kits
(Vehicles other than Frazier)

Main kit components (prices as of December 2000)

Proportional spool valve (c/w cables/fittings) £875
Electronic controller £320
Frazier control box, fitting & set-up instructions £330
Rotary sensors (2 @ £67.5) £135.00

Total £1660

Vehicle requirements

The above components are all required to control the steering system. The vehicle to which the system is to be fitted will require the following:

A rear steering axle fitted with a suitable hydraulic steering cylinder (We can calculate the size of ram required if necessary but would need the loaded axle weight, tyre sizes, track widths and various axle dimensions).

A continuous hydraulic oil flow of between 10 and 20 litres per minute at 2,000 psi (140bar) to the valve (dependent on ram size & travel)

A return hose from the valve directly to the hydraulic tank (1/2" & zero back pressure).

Hoses from the valve to the steering ram (3/8")

The two steering sensors normally connect to the top of one kingpin on each axle. A peg will be required protruding upwards from the centre of the kingpin to which the sensor is attached with a small drive coupling. A mounting bracket for the sensor will need to be fabricated and attached to the solid part of the axle. All the above will need to be well clear of the wheel. Alternative sensing arrangements are available if this is not possible.

A 12v power supply (fused 3 amp) direct from the battery

A 12v power supply (fused 3 amp) controlled by the ignition switch

A system can be fitted to remind the operator to switch to the roadwork position at high speeds. On some vehicles this can be done with a mechanical switch (e.g. a brake light switch) on the gear linkage so that it is activated when a certain gear is selected. Some vehicles may be fitted with an electronic speedometer that may have a programmable output at certain speeds. It is recommended that some sort of system be devised to give a 12v signal to the controller at speeds above 12 mph - The system must (for safety) be de-activated for all road work. A suitable electronic speedo can be supplied by Frazier if required at approx £275

For the "auto mode" to be utilised a 12v supply is required from the sprayer/implement controls when the sprayer/implement is switched off - a relay may need to be fitted.

Other parts & fitting

Frazier can also supply hydraulic hoses and fittings if required together with various hydraulic flow control and relief valves - additional valves may be required depending on the design of the hydraulic system on the vehicle - we can advise on this providing full details of the machines hydraulic system are supplied.

Frazier can supply a fitting service for the system and assuming the axle is fitted with the steering ram, hydraulic connections (as above) are available and there are no complications in fitting the sensors then as a guide this should take between 20 and 30 hours (£600 labour give or take a bit!)