Oct 6, 2021

Knocking noise from steering rack – what’s behind it? Let expert explain

Steering rack failure: how to detect

Almost every driver knows that the unusual sounds in the front part of a car, when driving the uneven road, are caused by the steering failure.And you know that the steering is the vehicle element that affects the driving safety. So the failure has to be eliminated without delay.

Where does the noise come from – the question you have to answer first. When you drive it may seem that it’s the steering rack that knocks, however, it also can be the tie rod as well as the tie rod end, in particular, the ball joints. Well lubricated and without moisture under the dust boot, the ball joints commonly serve for a long time. And if the visual inspection confirmed the integrity of tie rod end dust boots the source of sound, apparently, is in the steering rack.

The unusual sounds in the steering rack are commonly caused by two reasons:

  • Wear of the couple ‘gear-rack’.
  • Wear of the end bushing.

Gap in the couple ‘gear-rack’

During the car operation the teeth are being worn, and it results in the big gap between toothed rack and the driving gear. In addition, the steering rack bar may be worn as well as plunger/guide seat.

Initially, to eliminate the wear effects, you can adjust the gap between gear and rack by the tightening of the guide nut. This procedure can be carried out without dismounting of the steering rack from a car – depending on the car model configuration. At the same time, the repair quality will be higher if the steering rack is dismounted. Commonly, to tighten the guide nut, you will need the special tool. And in case of the excessive wear, the steering rack will have to be dismantled - to replace the non-serviceable parts.

End bushing wear

The typical defect of the steering system and the most common reason for the steering rack knocking – wear or failure of the end bushing that aligns the steering rack bar.

The high loads and the driving the bad roads causes the wear. To determine it, you can balance up and down the right and the left bar ends of steering rack. If you clearly hear the knocking, the replacement of the end bushing is required. The early diagnostics enables the replacement only of the end bushing not the steering rack assembly.

Equipment for steering rack diagnostics

For accurate diagnostics the steering rack is dismounted from a car. Then, to determine the real failure reason, use the special equipment – tester MS502M that will check the technical condition of HPS rack and identify the failure. For a complete diagnostics of EPS racks and columns as well as of EHPS pumps with any control protocol, the controller MS561 is required.

Master Service company develops and manufactures the equipment – under trade mark MSG Equipment - for the diagnostics of steering units. Besides, there are the test benches and testers for the diagnostics of starters, alternators, air conditioning system, shock absorbers, hybrid car batteries and other equipment in the product range offered to car service centers and car repair shops.

Visit our website servicems.eu to find out more about the equipment specifications or call +38 (057) 728 49 64.


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