ah ! resulting in 'knocking noises' !!  RR Sport Supercharged Vesuvius Orange 4.2 V8 First edition

Prefer RR Vouge S/C but they don't do Orange !

^^^ Yep........but I don't know if they swing that much while driving...... FF 4.4 V8 Soooo looking forward to this bad boy
Ex 2006 RRS SC - garbage
Ex 2016 135i M Sport - dream car
Ex 2003 RS6 Avant - piece of cr*p
Ex 2014 320d X Drive, M Sport Touring - ok I guess
Ex 2007 RRS TDV8 - bloody loved it
EX 2007 FL2 XS - not so bad

They are indeed Harmonic Dampers and are designed to swing as it were.

James  Follow us on Twitter: @GrangeBarnetJLR

This is an old topic

I don't think they actually get close to hitting anything actually in use Mike

2014 Facelift Discovery

If you can't wrap them,how about putting some wire around it and fastening that to a suitable point to reduce the swing thus stopping it banging.

mine hit the rear bumper. Like I said, I think the HST bumper is larger and so nearer to these weights. I've jammed a cloth up there at present until I can think of a better solution  RR Sport Supercharged Vesuvius Orange 4.2 V8 First edition

Prefer RR Vouge S/C but they don't do Orange !

Mine had two extra ones fitted under warranty to stop a rattle ,these ones are at the front of the sill behind the front mudflaps,except the dealer fitted them the wrong way around !!
So I reversed them and then they replaced the anti roll bar bushes which fixed the rattle.
As previously stated these harmonic vibration dampers are fitted to alter the frequency at which a component resonates where the original vibration frequency coincided with a common road/engine speed etc.
Pretty much everything solid ,especially big panels, on the car has a frequency at which it will start to resonate, these devices just make the component resonate at a different time that is hopefully outside the operating range of everything else.
Vehicle manufacturers employ NVH (noise,vibration,harshness) engineers to come up with fixes like this to make the cars smoother and quieter.
If you took them all off obviously it would make the car lighter but you would then get some odd and surprising vibrations and noises.
To demonstrate the concept hold a guitar in front of a hi fi speaker with your favourite piece of music playing and closely observe the strings, if its in tune you will see them individually vibrating in time with the music,if you then fret whichever string you can see vibrating the vibration of that string will stop.
Because you have changed the pitch of the string.
Same principle ,except on a car they just hang a big lump of steel off the part that is resonating.
Right ho,boring head off now and back to work.

DRDILL wrote:

Mass dampers, they are mounted with rubber so have some resistance, is the rubber on yours worn so swinging too loose?

well, this is the only thing I can think of. the trouble is 'have you seen where they are located?' It'd be a total nightmare to remove them to change the mount rubbers  RR Sport Supercharged Vesuvius Orange 4.2 V8 First edition

Prefer RR Vouge S/C but they don't do Orange !