Why can there be knocking in the steering rack when turning?
Content
Knocking in the steering rack when turning the steering wheel indicates a malfunction of this mechanism and the need for urgent repairs. But, before you start repairing your car, you first need to accurately determine the cause of the defect, because the order of further actions and the list of spare parts required for repair depend on this.
Knocking in the steering rack when turning the steering wheel when the suspension is in full working order indicates problems with the steering mechanism, so the car requires urgent repair, and neglecting the symptoms can lead to an accident.
What can knock in the steering rack
If you checked the entire suspension and did not find the causes of knocks, and the sounds made come from the side of the steering device, then their causes may be:
- the fastening of the rail to the car body has weakened;
- worn bearings and gear teeth;
- worn plastic support sleeve;
- worn anti-friction spacer;
- worn toothed shaft (rack).
These reasons are common to all cars with rack and pinion steering, regardless of the presence or absence of any amplifiers (hydraulic or electric). If, with an absolutely serviceable suspension, something began to knock during a turn, then after the diagnosis you will find one of these reasons.
This is what the steering rack looks like
Loose steering rack to car body
Proper operation of the steering mechanism is possible only when the rack housing is securely attached to the vehicle body. During the turn, this node is affected by fairly high forces from the suspension, so where the bolts are not tightened, play appears, which becomes a source of knocks.
This is what one of the fasteners looks like
Worn bearings and gear teeth
In a rack and pinion steering mechanism, bearings hold a shaft with a drive gear located at an angle to the toothed shaft, which is called the rack.
To check if bearings or worn teeth are causing knocking when turning the steering wheel on machines with power steering or EUR, check the steering wheel play with the ignition off.
This is what worn gear teeth look like
To do this, look at any front wheel and with the movement of one finger turn the steering wheel left and right by 1–5 mm. If the resistance to turning the steering wheel does not appear immediately, then the reason for the knocking of the rack has been established - it is worn bearings or gear teeth. It is possible to more accurately determine the cause of knocking in the steering rack when turning the steering wheel only after dismantling and disassembling the unit.
Worn plastic bushing
This part is one of two sleeve bearings that keep the gear shaft in constant position relative to the pinion, allowing the rack to move only to the left or right. When the bushing is worn, the edge of the rack farthest from the steering wheel loses its fixation and begins to dangle, which is why the knock appears not only during the turn, but also when driving on uneven terrain.
Damaged and new support bushings
Worn anti-friction lining
The clamping mechanism is the second plain bearing that holds the rack toothed shaft, and also, to some extent, compensates for the vibrations that occur in the suspension during turning or driving over uneven areas. The main symptom that confirms this malfunction is the backlash of the toothed shaft on the driver's side. To check and confirm or deny the suspicion, hang the front of the machine, then wrap your hand around the gear shaft from the side of the steering wheel, move it back and forth and up and down. Even a barely noticeable backlash indicates that the lining (cracker) has worn off, which means that the car needs to tighten the rail. If the tightening did not work, then you will have to disassemble the mechanism and change the lining, as well as check the condition of the toothed shaft.
Anti-friction pads
Worn toothed shaft
It is not uncommon for aging machines, as well as vehicles that do not receive high-quality maintenance, the rack toothed shaft loses its round shape due to abrasion in one or more areas. The main sign of such a defect is play on the left and / or right side, so an inexperienced diagnostician may draw the wrong conclusion, deciding that the problem is in a worn plastic sleeve or a worn anti-friction lining.
During the repair, if the one who carries it out has enough experience, it will be found that in addition to these defects, the rail itself is also damaged, so you will have to remove the entire device in order to replace or restore the damaged element. If experience is not enough, then the problem will be revealed after the repair, because the backlash will not completely disappear, although it will become smaller, due to which the same knock will appear during the turn.
This is what the gear shaft looks like
What to do
Since the cause of the steering rack knock that occurs during a turn is some kind of defect in this device, the only way to get rid of it is to repair the unit. Articles will appear on our site that tell about various ways to repair the steering rack, as they come out, we will post links to them here and you can go there without a long search.
Conclusion
Knocking in the steering rack when turning the steering wheel indicates a malfunction of this mechanism and the need for urgent repairs. But, before you start repairing your car, you first need to accurately determine the cause of the defect, because the order of further actions and the list of spare parts required for repair depend on this.
