Rotational noise from rear?

[thegfb]

A rotational 'click' noise has appeared at the rear of my S1 FHC 3.8. It only manifests itself after 15 miles or more of motorway or fairly high speed A road driving. It doesn't seem to be brake linked as it doesn't disappear if I touch the brake pedal. The car runs on standard size wheels with Avon Turbospeed tyres so I don't think it's a tyre rubbing issue though as I don't have a car lift I can only jack the car and, of course, the wheels drop so I can't check if there's any rubbing. Anyway it doesn't seem to related in any way to whether the suspension's compressed or not as it is at it's most audible if I sit in the car and roll at low speed and listen with the car door open.

Any ideas?

[christopher storey]

It might be advisable to check your wheel spokes . Run the wooden handle of a fairly substantial screwdriver over them, and listen for any which sound dull. Also have a look to see that none are missing !

[thegfb]

I replaced the wheels fairly recently with new painted items from MWS (think they look better on a very early car) but, nonetheless, I will check as per Christopher's suggestion (thank you very much for your response).

If it's not that might it be diff linked? Or perhaps one of the UJs?

I know it's almost impossible to be definitive without seeing the car but any further hints which might take me in the right direction would be much appreciated.

[Heuer]

Have you put limited diff additive into the rear axle or used the correct fluid with additive?

[christopher storey]

With new wheels my suggestion of loose spokes seems unlikely . Is it once per wheel rotation, or once per propshaft rotation i.e. about 3.3 clicks per wheel rotation ( assuming you have the 3.31 final drive ) ? And have you checked those pestilential UJ covers at the outer end of the driveshafts - they are forever moving and touching something as they rotate - I abandoned mine as a result