Incorrectly Adjusted Steering Gear Plungers – Part 2

  Welcome back to Incorrectly Adjusted Steering Gear Plungers, part 2.

For those who have not read part 1, follow the link below to learn about the issues the adjustment of plungers cause on a vehicle.   Incorrectly Adjusted Steering Gear Plungers – Part 1

In this article we will discuss when and how adjustments need to be made to steering gear plungers.

What will cause Incorrectly adjusted steering gear plungers?

Many day to day maintenance activities such as a draglink end replacement will force the need to adjust the steering gear plungers.

Adjustable Draglink

Replacing a draglink end / draglink or Adjusting a draglink could lead to Incorrectly Adjusted Steering Gear Plungers

The need to adjust is due to changes in the relative position between the steering gear piston and the steering axles straight ahead position, the draglink end will note be in exactly the same position as the old one, which changes the relative position between steering gear piston and the steering axle straight ahead position. This problem is also present when a steering gear is replaced, front axle caster is adjusted, draglink adjusted / replaced  or the front suspension replaced/reset or any similar change.

How to check the adjustment of your steering gear plungers

Checking the adjustment of your steering gear plungers could not be simpler. Begin with the engine running at an idle with the steering wheels on the ground, i.e. normal road conditions. Get someone else to turn the steering wheel full lock first to the right , once full lock is reached have them maintain a slight pressure on the steering wheel so the system is held in position.

While the steering wheel is at full lock to the right measure the gap at the right axle lock stop, it should be 3mm or 1/8″, if it is any more you are loosing valuable lock, any less you risk all of the problems we discussed in Part 1. Once complete repeat the process for the left hand lock stop.

Lock Stops - Courtesy HFB70 Service Manual

Lock Stop or Axle Stop Clearance Courtesy HFB70 Service Manual


A handy hint is to have a 3mm or 1/8 ” gauge made up (think thick feeler gauge), if you can insert the gauge into the gap without it being able to rattle then the system is correctly adjusted, if you can rattle the gauge you should adjust the plungers to achieve more lock. If you can’t insert the gauge at all you have less than 3mm gap and should adjust the plungers to prevent damage to your power steering system.

How to adjust Incorrectly Adjusted Steering Gear Plungers

There are two main types of steering gear plungers, manual and automatic plungers. Both automatic and manual steering gear plungers can become incorrectly adjusted.  Automatic plungers are a whole story in themselves which we will leave to another article.

When adjusting manual plungers the first challenge is to identify which plunger is active on RH lock and which is active on LH lock. First measure and record the lock stop gap for both Left Hand Lock and Right Hand Lock following the method used earlier to check if you needed to adjust at all (ideally record it when you checked).

Steering Gear Plunger

Lock Nut Style Adjustable Plunger

Once you have the taken the measurement pick one plunger (pick the one which needs adjusting), adjust it in 4-5 turns and re-measure both LH and RH lock stop clearance’s, the lock with a different clearance relates to the plunger you have changed.

Continue to adjust the plungers, checking the lock stop clearance until a lock stop gap of 3mm or 1/8″ exists. Repeat the process with the other plunger and the remaining lock stop gap. Always complete these measurements with the engine running at idle and a slight pressure on the steering wheel to keep the system on the relevant lock stop. The result will be a vehicle with maximum LH and RH steering lock, minimum chance of a pump which regularly goes into relief, and minimum chance of mechanical damage to steering system components. This will reduce unplanned maintenance and wear and tear on your vehicle.

, , , , ,

No comments yet.

Leave a Reply