Stumped - excessive noise from the front axle

[corned]

I have been stumped by some noise coming from the front end for a few weeks now.

Yesterday I had both front bottom ball joints on each rear track control arm renewed, plus both front wheel bearings.

This has eliminated the slight knocking from the front (ball joints) and significantly reduced the rumbling whine (bearings), but there remains a noise which I can't identify.

The known facts are as follows:

It's definitely the front.
It's definitely not the bearings.
The front brake pads are getting pretty thin.
The tyres are in good condition and about 40% worn.

It could be the tyres causing the noise, but I would like to know if others have had noise from their Falken FK452's? I have them all round, but the fronts have about 14,000 miles on them; the rears about 5,000. The alignment was done by WIM about 3 months ago, so I doubt it is noise from the tyres 'scrubbing'.

Could the thin brake pads cause such noise? Does SBC hold them so close to the disc that a thin pad makes some noise?

Or is it (as I suspect most likely) in the tyres? If so, does anyone else have experience of noisy FK452s?

Or could it be something else completely that I have not thought of? Again, any ideas are welcome.

I plan to swap the front tyres to the rear this weekend, just to see if the noise follows them (or not). Process of elimination, etc.

I open it to the floor...

 

[Sp!ke]

ARB bushes?

 

[corned]

Thanks, Spike. Hmm - not confident on that one, but thanks for the suggestion.

I forgot to say that the noise increases in pitch/frequency as road speed increases. I suppose it's not too dissimilar to bearing noise, but 'smoother' if you get my meaning?

 

[BlackC55]

Are the tyres feathered?

 

[corned]

Not at all. WIM did a good job! (And so did I - I don't do door handle-scraping cornering often!)

 

[Sp!ke]

Ahh I thought you were saying it was a knocking noise.

What makes you so confident the wheel bearings are OK?

How are your disks - much of a lip to them?

 

[moonloops]

My CLK had various bits of worn suspension - ball joints I had replaced. What I was left with was a bearing type noise. It was the wear pattern on the tyres caused by balljoints.

Changed the tyres, noise gone. My snow tyres actually made less noise and had a softer ride than the weirdly worn michelins.

Hope that helps.

 

[Bellow]

It's definitely the front.

That's what I thought when I had my W123 and it transpired that the noise was from the rear! Deceptive...

And if from the rear, as it is speed related, the drive train could be the culprit.

For now though, I doubt that you are far off suspecting the tyres. They do get noisier as they wear, and the roads being cold still must be pretty unyielding.

Would altering the tyre pressure - both higher and lower - help identify or eliminate them as suspects? (Experimental runs only - safety first!)

 

[corned]

Ahh I thought you were saying it was a knocking noise.

What makes you so confident the wheel bearings are OK?

How are your disks - much of a lip to them?

Thanks, Spike. The bearings are brand new, so I hope they are absolutely silent now! At least one side was making a noise, which is why I had them changed in the first place. It's just that I am left with a little noise even after this work.

Discs have a slight lip, not >1mm, but pads are down to about 3mm.

 

[corned]

My CLK had various bits of worn suspension - ball joints I had replaced. What I was left with was a bearing type noise. It was the wear pattern on the tyres caused by balljoints.

Changed the tyres, noise gone. My snow tyres actually made less noise and had a softer ride than the weirdly worn michelins.

Hope that helps.

Thanks. I think tyres have to be the best bet. I'll soon know when I have swapped them around... I after I have done that I moght try a few drag starts for a while and see if the rear can wear them quiet again!

 

[corned]

That's what I thought when I had my W123 and it transpired that the noise was from the rear! Deceptive...

And if from the rear, as it is speed related, the drive train could be the culprit.

For now though, I doubt that you are far off suspecting the tyres. They do get noisier as they wear, and the roads being cold still must be pretty unyielding.

Would altering the tyre pressure - both higher and lower - help identify or eliminate them as suspects? (Experimental runs only - safety first!)

I can try tyre pressure changes. Good idea - thanks for the tip!

 

[flango]

The main reason I stopped using Falken was because of the very obtrusive road noise they gave out. Good tyre great grip and performance but bloody noisy. Hope that cures it Keith

 

[corned]

Me too!

It's funny. The noise is a lot less than before, and it is now different in sound, but it bugs me because there's still something there...

And it's very noticeable how much of a difference those new ball joints have made - front end feels a lot more solid. No crashing over lumps and bumps any more!

JAR Motorsport gets a from me! Thanks, Ian.

 

[wemorgan]

It might be worth checking that the undertray and engine cover are both securely fastened. Any fluttering at speed could cause a droning noise.

 

[corned]

Hmm - I hadn't thought along those lines!

Thanks Will, I'll check those out.

 

[kwakdonut]

Try the Kumho tyres possibly - I find them very quiet on mine

 

[corned]

Happily moving the fronts to the back took the remainder of the noise with them. And almost made it un-noticeable into the bargain. The rear axle must be better insulated against noise transmission into the body...

N.B. I would have added [SOLVED] to the thread but can't find any option to do that. I thought it was on the 'Additional Options' panel but it is not there, nor is it apparently anywhere else.

 

[wemorgan]

Nice result

re solved: It's usually in Thread Tools - near top right when viewing the thread.

 

[davidjpowell]

Interesting. Sounds like this would have solved one of the bug bears I had on our W211. Good result anyway!

 

[corned]

Thanks guys.

I'm not necessarily out of the woods though. What happens if the rears, now on the front, start making the same noise in 8,000 miles?

Hopefully, as moonloops suggested, the noise has been caused by odd tread wear factors due to the wonky ball joints - although nothing is apparent when looking at the tyres. We'll see...


Edit to add: Found the [SOLVED] thing, exactly where Will said it was. Thanks mate!