Steering knocking sound

[John Kenny]

Hi Guys,

When i turn the steering on my 07 saab 93 there is a knocking sound.

Any ideas what it might be?

Sounds like its coming from the steering rack or box?

[9-3 Aero]

You didn't specify good - or bad ideas (), so I'll elaborate a little on the issue, as it is of course hard pointing dead on towards the culprit.

There is one universal - and one joint on the steering linkage, which could be the cause of the problem. Then there are the joints where the left - and right drag link end fits to the steering swivel housing (to which the brake discs fits and the wheel bearing housings are).

The drive shafts have universal joints, protected from dirt by bellows. When the bellows go bad and dirt penetrates into the joints, or they are worn out, sound will be produced in sharp bends on even surfaces.

In the front wheel suspension is a bushing subject to wear, however would I believe a squeak is more likely being the sound when worn out.

There is issued a Technical Service Bulletin, cars affected within VIN range 31000001 - 71004117, with symptom description: "Knocking noise while turning the steering wheel, or banging noise when driving on uneven roads." Check the VIN of your 9-3 (given it is a 4D/5D, CV VIN range is different).

What you could do, is to raise the car, left - right front, one at a time, and wiggle the wheel horizontally and vertically to possibly narrowing the area where the culprit is hidden. The feeling should be tight and obviously with no "bumps". Pull the drag link ends and note for tightness.

When the 9-5 we had drove on a particular spot, uphill and in a right turn, a knocking sound was heard. It turned out to be a manufacture flaw; to little grease applied on the surfaces of the wheel bearing housing on the steering swivel.