Incorrectly Adjusted Steering Gear Plungers – Part 1

 Incorrectly Adjusted Steering Gear Plungers could be damaging your steering system!

Often forgotten in the power steering gear are the lock relief valves or the lock limiting plungers. There are two main types of plungers, manual and automatic, they are both designed to relieve the hydraulic pressure in the steering system just prior to full lock, to avoid the power steering system reaching pump relief pressure, protecting the steering linkage system from damage all while maximizing the available steering lock.

Steering Gear Plunger

Lock Nut Style Adjustable Plunger

Avoiding pump relief pressure.

Hydraulic power steering pumps relieve at pressures in excess of 130 bar or 2000 psi. A pump operating in relief will generate high fluid temperatures because as much energy as a two bar electric radiator can be generated when a pump is relieving.

This over time this will cause a significant reduction in the life of the power steering system pump, gear and system hoses, increasing maintenance costs and unplanned vehicle downtime.

Protecting the Steering Linkages

When the power steering system is pushing against the mechanical stops due to Incorrectly Adjusted steering gear plungers it can exert as much as 3000 kg’s of force to the draglinks and other axle components.

This can cause undesired bending of the draglink and excessive stress on other components of the steering and axel system. This problem is multiplied on twin steer axel vehicles, when the between the axel draglink can be bent causing misalignment between the axels. This increases tire wear as the two sets of tires are no longer parallel to each other in the straight ahead position.

Overset Plungers

Incorrectly adjusted steering gear plungers or plungers which have not been correctly set to maximize the lock  whilst protecting the hydraulic pump and steering linkages may be causing uneven left and/ or  right lock and generally increasing the turning circle of the vehicle making it more difficult to drive.

Look out for part 2 of this blog for more information. Part 2

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