The steering system used in the Holden HK, HT and HG models was designed to provide reliable control and stable road handling across a wide range of driving conditions. These vehicles used a recirculating ball steering gear along with conventional steering linkages and, in many models, a Saginaw hydraulic power steering system to reduce steering effort.
Although the design was robust and well proven, steering components can wear over time. Incorrect adjustments, worn linkages or problems within the power steering hydraulic system can lead to symptoms such as heavy steering, looseness in the steering wheel or abnormal pump noise. Understanding how the steering system operates and what faults commonly occur helps owners and restorers diagnose problems before major repairs are required.
Steering System Design
HK, HT and HG Holdens use an energy-absorbing steering column connected through a flexible coupling to a recirculating ball type steering gear. This design converts steering wheel rotation into movement of the pitman arm, which then operates the steering linkage and front wheels.
Key steering system features include:
• Energy absorbing steering column for improved safety
• Flexible coupling between steering column and steering gear
• Recirculating ball steering box design
• Adjustable steering gear lash
• Optional hydraulic power steering system using a Saginaw vane pump
Power steering systems use hydraulic pressure generated by a belt-driven pump to assist steering movement, reducing driver effort particularly during low-speed manoeuvring.
Common Steering Problems
Several faults can affect steering operation on HK-HG Holdens. These are generally related to wear in steering components, incorrect adjustments or problems in the hydraulic power steering system.
Typical steering complaints include:
• Excessive play or looseness in the steering wheel
• Hard steering requiring excessive effort
• Steering gear rattle or noise
• Poor steering return after cornering
• Power steering pump noise
• Hydraulic fluid leaks
Correct diagnosis requires identifying whether the problem originates in the steering gear, suspension components, or the hydraulic assist system.
Hard Steering
If steering effort becomes unusually heavy, several mechanical or hydraulic issues may be responsible.
Possible causes include:
• Low or uneven tyre pressure
• Insufficient lubricant in the steering gear
• Steering gear adjustment too tight
• Steering shaft coupling misalignment
• Incorrect front wheel alignment
• Air trapped in the power steering hydraulic system
• Low power steering fluid level
• Worn or damaged power steering components
Heavy steering may also occur if the drive belt operating the power steering pump is loose or slipping.
Excessive Steering Play
Excessive movement of the steering wheel before the wheels begin to turn is usually caused by wear in steering linkages or incorrect steering gear adjustment.
Common causes include:
• Loose or worn steering ball joints
• Loose pitman arm on steering shaft
• Worn steering linkage components
• Front wheel bearings incorrectly adjusted
• Excessive backlash in steering gear
Correct adjustment of the steering gear and inspection of linkage components normally resolves this problem.
Steering Gear Noise or Rattle
Noise or vibration from the steering gear often indicates incorrect internal adjustment or component wear.
Possible causes include:
• Insufficient lubricant inside the steering gear
• Excessive backlash between the ball nut and pitman shaft sector
• Loose steering gear mounting bolts
• Worn steering shaft bearings
It is important not to over-adjust steering gear lash in an attempt to eliminate slight steering noise, as excessive adjustment can lead to steering stiffness and premature wear.
Power Steering Pump Noise
Noise from the power steering pump can occur when air enters the hydraulic system or when internal components begin to wear.
Typical causes include:
• Loose drive belt
• Low hydraulic fluid level
• Air in the hydraulic system
• Restricted or damaged hoses
• Scored internal pump components
• Worn pump ring or rotor
Bleeding the hydraulic system and ensuring the correct fluid level is maintained will often eliminate pump noise.
Power Steering Fluid Leaks
Hydraulic fluid leaks can occur at several points within the system.
Common leak locations include:
• Reservoir overfilled
• Air trapped in fluid causing overflow
• Loose or damaged hose fittings
• Damaged O-rings or seals
• Cross-threaded or improperly tightened fittings
Hydraulic connections must be correctly tightened and damaged seals replaced to prevent fluid loss and maintain correct steering operation.
Steering System Specifications
The HK-HT-HG steering system uses a recirculating ball type steering gear with the following general specifications:
• Steering gear type — recirculating ball
• Steering ratio (standard) — 20.0 : 1 gear ratio / 23.6 : 1 overall
• Optional fast ratio — 16.7 : 1 gear ratio / 19.8 : 1 overall
• Number of balls in steering gear —
• 20:1 ratio: 50 balls
• 16.7:1 ratio: 54 balls
• Steering gear lubricant capacity — approximately 9 fluid ounces
• Steering gear lubricant specification — GMH CG.1
• Worm shaft bearing preload — ¼ to ¾ lb pull at 7 inch radius
• Pitman shaft lash adjustment — 1¼ to 1¾ lb pull at 7 inch radius through no-lash range
Power steering equipped vehicles use a Saginaw vane-type hydraulic pump with operating pressures approximately:
• V8 engines — 1000 to 1100 psi
• Six cylinder engines — 540 to 670 psi
These pressures provide the hydraulic assistance required for smooth steering operation while maintaining road feel.
While this guide helps identify common steering system problems, the Holden workshop manuals available from Car Manuals Direct include the original specifications, adjustment settings and repair procedures used by Holden mechanics when these vehicles were new.