Live axle knock

[Ralph Morgan]

On low speed, tight right hand bends, such as mini roundabouts, turning into side roads and the like, I can hear and feel a "clonk" from behind the driving seat in my Ital axled car. I've jacked it up and can't feel any slack in the suspension or hub, and nothing was picked up at the recent MOT, so I think it must be something within the axle itself.

 

Does anyone else have similar experience and/or suggestions as to the cause or solution?

[elie boone]

Your first check would be the central rubber bush under the diff, do a search and you will find plenty of info about the live axle knock.

 

[Ralph Morgan]

Thanks Elie,

 

Forgot to mention in my OP that I changed the A frame bush as a first stage in the investigation but it didn't get rid of the clonk.

 

Can't help thinking it's in the diff. It probably happens at higher speeds too but gets drowned out by other noise. My fear is that something will "let go" suddenly with unpredictable results

[virden]

Just a thought : have you checked the bushes in the trailing arms?

[Ivaan]

Is it just a single clonk, or multiple clonking?

 

Any relationship with wheel or prop speed?

[davedlr]

I had a knocking on my live axle after it had been overhauled - it turned out to be the handbrake cable had not been secured and was flapping about under cornering.

 

I hope your problem is as simple to solve...

[Dave H]

It could be the bearing moving on the half shaft. Once it has started to move it will progress quickly as the car acts like a giant slide hammer every time you corner.

 

It's been discussed on here, but not for a while here

 

Dave H

[Ralph Morgan]

Thanks for all the tips. I wondered about the radius arm bush but can't feel any movement. Perhaps I need to disconnect it one end to investigate further.

 

It's a single clonk, and only on right hand bends. I only notice it at low speeds (say, 10mph or so). I did wonder about the halfshaft bearing, but would have thought I'd find some end play in the hub, which I can't, a and the MOT tester didn't either..

 

I'll dig back through the archives. Thanks for the link Dave.

 

Edited by - Ralph Morgan on 11 Apr 2014 16:45:21

[elie boone]

To check the half shaft bearing rock the car from side to side, if there is any movement from the bearing on the half shaft you will feel it. Also check g.box & engine mounts.

[abbot]

If it is a problem with a floating shaft you will probably feel it as we'll. that is what triggered my curiosity when my shaft started to move on the bearing.

[Jochen]

Had the very same problem. Solved by changing the radius arms bushes.

Almost the same noise accrues if the bearings of the cardan joint get knocked out.

 

Hope i found the right technical terms...