TB7 - Technical Bulletin 7

Power Steering Conversion

  • HQ-HZ power steering box

    Fitting power steering was a popular option for HQ vehicles already known for their heavy steering, even with the 6 cylinder engine installed.

    Power steering was almost a necessity for V8 engined vehicles..

    Converting to power steering is a relatively easy task but there are a couple of traps to be avoided.

    Important: All models fitted with power steering used the HQ steering arms which are shorter. From the HJ model onwards, longer steering arms were used to reduce steering effort. Using these steering arms makes the steering excessively light.

    Other factors affecting steering effort are tyre width, tyre grip and castor/camber settings.

    The components necessary for the conversion are:

    • Power steering pump with mounting bracket to suit engine
    • Power steering box with pitman arm
    • Steering shaft power steering flexible joint
    • Suitable multi vee crank pulley
    • Suitable length fan belt
    • 3/8” ID High pressure hose from steering pump to steering box
    • 3/8” ID Low pressure return hose
    • 2 hose clips for LP hose
    Power steering pump fitted to Rover V8 using custom bracket
    Steering pump fitted to Rover V8 using custom bracket

    The original drag link and steering idler support and idler arm are retained.

    Important: Pitman arms fitted to steering boxes came in two versions:
    Part No. 2809281, 20:1 ratio 180mm long (approx.) and
    Part No. 9935627, 25:1 ratio 185mm long (approx.).

    Use the shorter arm as the steering will be too light, even with a V8 fitted, due to the Cheetah weight distribution being close to 50/50.

    Once the conversion is completed and the pump filled with suitable oil, turn the wheels fully lock to lock with the engine running to dispel any air in the system.

    If the wheel alignment has already been set, it would be advisable to get it re-checked. If a different length pitman arm has been used, it will be necessary to have the wheel alignment reset.