Think your wheel bearings are knackered? No its far simpler than that.

[aw1234]

I have a 2003 MCS and it has a droning sound from about 30mph upwards.

I have replaced all 4 wheel bearings and its still the same.

There is a lot posted on here about tyres causing the noise, so I took a closer look.

Its not in any way apparent but the droning is caused by a form of tyre wear called "saw teeth".

Essentially on the inside edges of your rear tyres, the tread blocks wear so they have a high leading edge. With the blocks rotating fast, at some speeds the resulting sound wave is inaudible. At others it creates a droning sound which sounds just like worn wheel bearings.

If you swap these wheels to the front, the noise will reduce 80%

If you replace the tyres (though they may not be that worn - mine still have 5mm of thread) the drone shall be banished forever.

Be especially aware of your dealer if they charge you for new tyres and wheel bearings!

You can dial out the saw tooth effect on cars with adjustable rear geo. My R53 MCS does not. If the sharp edges of the tread sections are pointing to the centre of the car, then there is too much toe-in. If they are pointed to the outside of the car then there is too much toe-out.

You'll only get the problem on the rear of a FWD car.

[ash_bash]

Useful thanks!

I've noticed my rear tires are scrubbing and now badly worn on the inside only.

I was told by a mechanic it 'could be' the control arm and/or bushes, is that right or is it just a suspension setup issue?

Thanks

Ash

Quote: Originally Posted by aw1234 (original)

I have a 2003 MCS and it has a droning sound from about 30mph upwards.

I have replaced all 4 wheel bearings and its still the same.

There is a lot posted on here about tyres causing the noise, so I took a closer look.

Its not in any way apparent but the droning is caused by a form of tyre wear called "saw teeth".

Essentially on the inside edges of your rear tyres, the tread blocks wear so they have a high leading edge. With the blocks rotating fast, at some speeds the resulting sound wave is inaudible. At others it creates a droning sound which sounds just like worn wheel bearings.

If you swap these wheels to the front, the noise will reduce 80%

If you replace the tyres (though they may not be that worn - mine still have 5mm of thread) the drone shall be banished forever.

Be especially aware of your dealer if they charge you for new tyres and wheel bearings!

You can dial out the saw tooth effect on cars with adjustable rear geo. My R53 MCS does not. If the sharp edges of the tread sections are pointing to the centre of the car, then there is too much toe-in. If they are pointed to the outside of the car then there is too much toe-out.

You'll only get the problem on the rear of a FWD car.

[Munich]

I experienced exactly the same problem with my Mini. At speeds over ca. 50kph there was a definite audible droning type noise coming from the left rear wheel area and was thinking exactly the same as you, that I needed new left rear wheel bearing.

However, before I got round to doing anything about it I had the car serviced and I needed new tyres all round. The dealer didn't mention anything about needing new wheel bearings and when I took the car back, the noise was gone.

What I wasn't aware of was the "name" of the problem, so thank you for that.

[srtoad4]

Getting new wheels/tires fixed all of the noises my car would make while accelerating. It used to make a shh-shh-shh noise that would go faster and faster as I sped up. I thought it was bad rotors and/or bearing. New wheels/tires fixed all the noises, and car is quiet as can be now! Didn't help that the old tires were from 2002!