Knocking upto 10mph

**randall977** · 22-04-2009,12:33 PM

When I pull off slowly I get a knock from what feels like the front wheels (which I believe relates to the wheel revolution) upto about 10mph then it's fine after that. It feels like I am driving over a series of catseyes. If I pull off quickly it doesn't do it - it is mechanical - so not the tyres. The car is an 05 1.8T Cabrio Quattro - manual.

Any idea what could be causing it?

**dod1e** · 22-04-2009,12:54 PM

Could be the Constant velocity (CV) joint. If the rubber boot that covers it is compromised then the grease will escape and it wont be long before it starts knocking.

After that it could run for long enough, but even if you re-grease and fit a new boot, it will still knock for ever more.

If your boot needs changing then the CV joint needs to come off anyway so might as well replace.

**JohnyIre** · 22-04-2009,12:57 PM

This should be really obvious if you have the wheel turned one either all the way left or right and driving slowly. You should really hear the knocking then.

**randall977** · 22-04-2009,03:04 PM

So drive slowly turning on way then the other and see which one knocks the loudest? Will it be the CV on the side which I am turning - as in if I turn right and it knocks then it's the right CV? Thanks for your suggestions!

**JohnyIre** · 22-04-2009,03:13 PM

Originally Posted by randall977

So drive slowly turning on way then the other and see which one knocks the loudest? Will it be the CV on the side which I am turning - as in if I turn right and it knocks then it's the right CV? Thanks for your suggestions!

Not always. Basically when you have the wheel all the ways to one side you are making the CV joint turn as shaply as possible, and you have the best chance of finding out if this is the issue. If you do hear this knocking it should be loud enough that you can tell which side it comes from. Also, looking to see if the rubber boot is torn should help you see which side is in trouble.

**rhencullen1989** · 22-04-2009,03:15 PM

No, not exactly, as when you are on full lock both o/s and n/s front cv joints are at their extremes. I would personally doubt that it is a cv joint as these usually only "click" when on full lock i.e going into a parking space etc when they are worn (the clicking noise is the balls inside trying to ride up the grooves that they lie in)

Get some one to stand near to the front of the car when you pull away slowly and see if they can determine which side is making the noise. (don't run them over!)

Have you checked tyres, brakes etc?

**JohnyIre** · 22-04-2009,03:23 PM

Originally Posted by rhencullen1989

No, not exactly, as when you are on full lock both o/s and n/s front cv joints are at their extremes. I would personally doubt that it is a cv joint as these usually only "click" when on full lock i.e going into a parking space etc when they are worn (the clicking noise is the balls inside trying to ride up the grooves that they lie in)

Get some one to stand near to the front of the car when you pull away slowly and see if they can determine which side is making the noise. (don't run them over!)

Have you checked tyres, brakes etc?

Actually what I though. But good to eliminate the CV first. Could well be a brake issue.

**randall977** · 23-04-2009,08:32 AM

I have looked at the CV boots and they are perfect - and look original. I can't think how the brakes would cause the knock - it does literally feel like you are driving over cats-eyes or little ridges when you pull off. I surpose it's possible that there is a broken bearing in the front wheel???? Once the torque is increased the play disappears???

**rhencullen1989** · 23-04-2009,12:29 PM

Aah, so as well as hearing a "Knocking noise", you are also experiencing a sort of sensation as if you were driving over cats eyes?

Does it do this if you slowly roll down a hill starting from a standstill in neutral (if not, eliminates tyres/wheels/brakes etc.)

Possibly clutch related or drive shaft. (did you not have a drive shaft issue in a previous post?)

**randall977** · 23-04-2009,01:40 PM

Yes I do also have a problem with the front jumping (like driving over small ridges) when on hard lock - ie it does it when I take the car out of the garage - I was told it is probably the tyres scrubbing but more likely to be the same problem. I can live with it but right now I can get two complete L & R genuine front driveshafts for £150 (new) - so I could easily swap them. I don't want to if that's not the problem.