Anything and everything Vitesse.

General Vitesse messages

My Vitesse is vibrating all through the car at speed over 65 miles an hour, which makes it uncomfortable for motorway driving.

Could you tell me the problem

Main suspects would either be wheels out of balance or propshaft out of balance.

Look in the mirror while driving alomg at night, if the vibration causes the lights of following cars to vibrate in a circular motion in the mirror looking like a little circle then it's the prop.

Also, if it's wheels out of balance the vibration may dispapear or reduce at higher speeds so try increasing the speed if you get to over say 85 mph and the vibration has only got worse again this may point to the prop more likely being out of balance than the wheels.

If the props out of balance then best bet is to rebuild with new UJs before getting rebalanced, or get a reconditioned prop which should already have new UJs and have been balanced.

[QUOTE]Look in the mirror while driving alomg at night, if the vibration causes the lights of following cars to vibrate in a circular motion in the mirror looking like a little circle then it's the prop.[/QUOTE]

Don't know if that helps Paul but you've just told me it's the prop out of balance on my 2000

The trick of looking in the mirror in the dark at car lights bbehind you to see if your prop is out of balance was something I learnt in a discussion at Stafford this year froma fellow GT6 owner who had a bad vibration. Aparantly the advice came from Adam Chignal originally, and it sounded logical to me.....

dont forget about the halfshafts at the rear they also cause vibration

hugh

All,
I don't doubt that someone noticed a circular image in their mirror and then found a propshaft out of balance.
But this is not diagnostic for a propshaft problem.

If you have two ocillating inputs into a system that can ocillate in two directions, then deepending on the frequency and amplitude of the inputs, you get a range of simple to complex outputs that are described as Lissajou figures. If you played with a Harmonograph as a child, you'll know these.
See: http://local.wasp.uwa.edu.au/pbourke/surfaces_cur...
Extend that to a system that has multiple vibration inputs, that can oscillate in three dimensions, and the possible outputs are very complex indeed.
See: http://www.lifesmith.com/lissajou.html
But a light reflected in a mirror will be seen as ocillating in only two dimensions.
The third becomes invisible and the rough circularity is what stands out.
The stronger the input, the greater the output, so what would otherwise be a slightly blurred, wobbly light, becomes a circle - but that input can be any powerful vibration.

The light circle in your mirror confirms that the vibration you feel is in your car, not just a rough road or a hangover.

John

Generally there is a second harmonic of the orignal vibration which should occur at twice the orignal revolutions.

In practical terms if the prop vibrates at say 40 MPH then disappears passed this speed it will reappear at 80 MPH. If yours starts at 65 MPH don't try to do 130 MPH to prove the point!

Most Vitesse prop vibration problems occur at around 45 MPH.

Past experience with all models of the Vitesse has show the major cause of vibration is due to the prop shaft being out of balance and worn u/j's or spine.

On the Mk11 due to the use of the Rotoflex coupler this can hide quite badly worn u/j's to such an extent that they are very close to failure before it is apparent there is a problem. So check the condition of both the coupler and the u/j's.

Another cause can be lose bolts holding the bellhousing to the back plate.

Has it got overdrive ? we chased a similar problem changing and checking all that rotated to no avail
it was a d type unit and resetting the planet gears and aligning the dots and etched marks as per the book solved it
just a thought Peter

Section : General

Vibration At Motorway Speeds

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Vibration At Motorway Speeds

Vibration At Motorway Speeds

Vibration At Motorway Speeds

Vibration At Motorway Speeds

Vibration At Motorway Speeds

Vibration At Motorway Speeds

Vibration At Motorway Speeds

Vibration At Motorway Speeds