Steering thunking... Augh!

[Tiger]

I spent alot of time trying to figure out where the thunking is coming from on steering system.

Both tie rods, center link and passenger lower control arm is changed just recently. Upper control arm is 4 years old.

When both wheel on the ground and wiggle the steering wheel, you hear and feel thunka thunka. With passenger side wheel up in the air and shake the wheel, you get thunka thunka... Try this on the driver side and no sound at all.

From inside on steering shaft near the floor, you can feel that thunka when you wiggle the steering.

I checked the upper control arms and no play when wiggling steering wheel.

So what is thunking? After I had the car aligned with steering components changed, the car was with no noise and play at all. And about a week later... monster pothole at moderate speed... bam! Got the thunka.

Any idea? I thought it is the idler arm, but not sure. I already have the part and will put it in someday. What would give away after hitting such a bad pothole? I checked every ball joints on the new center and tie-rods... doesn't seems to be any problem.

[ahlem]

About the only thing left to change is the idler arm. I just did mine a couple months ago. Not too hard of a job. You can observe them by putting the car up on jackstands and pushing against the backs of the tires and see if anything moves.

[Mr._Graybeard]

Ummm... strut mount?

[Tiger]

Strut mount?! Car is on ground and not moving... wiggling cause thunka... strut mount? Please explain.

[Jehu]

Uuuuhhh how about the Sway bar Linkage? I had a clunk chunk when goin g over bumpy pavement, changed that and all is quiet... sway bar links...ftw.

[632 Regal]

steering U-joint is next link down there... also check nut behind the wheel first link on other side. If both check out then steering box...

Thats my guess.

[Tiger]

That's new too... remember... car is sitting still in the driveway... and if you wiggle the steering wheel left right... thucka thunka. That thunka is strong on the center link... just hard to isolate where it is coming from... but then again, I didn't get underneath the car with that cover off... I was reaching in with car jacked up a little bit for more room ro reach in.

[Tiger]

Possible... will check that. I did check inside the car... steering flex disc is good... I tighened the nut to the shaft by the floor... tight... so I have to go under the car to check the U joint?

Mmm... I think I better stufy up more on this. I thought the gearbox shaft is sticking through the floor on the 540i.

[Ross]

Does it rattle over bumps? Ball joint(s).

[Mr._Graybeard]

Strut mount?! Car is on ground and not moving... wiggling cause thunka... strut mount? Please explain.


If the car's on the ground and not moving, and you work the steering, if the strut bearing or mount has failed the turning motion can load up the coil spring and even cause it to rotate in the strut, producing a thunking sound.

While moving, the failed mount can also rattle over bumps.

You hit a pothole. What would take the shock of a street impact?

[Tiger]

Mmm... makes sense... I was trying to figure out what took the brunt of the force... So by putting my hand on the strut tower, I should feel that thunking right?

[Mr._Graybeard]

Mmm... makes sense... I was trying to figure out what took the brunt of the force... So by putting my hand on the strut tower, I should feel that thunking right?

Look for any rotational movement of the coil spring while a helper turns the steering wheel. You might be able to see displaced parts in the strut mount as well, but the spring twisting is a dead giveaway.