So THAT'S what it was!

[Nick Salmon]

On the way back home from Beaulieu the Ruby had been going beautifully. Near Andover, as I went onto the overrun down a hill there was a sudden repeated banging which we could feel through the floor. It was not engine or gearbox but seemed to be in vicinity of the propshaft and it was speed related. I found that it lessened in intensity when coasting but was awful if using engine braking to slow down. Looked around underneath, tugged at propshaft, torque tube etc. Could not see anything amiss. Decided to gently continue and in the end made it home without further problem.

This morning I went to investigate. There was way too much grease around the torque tube anchor which led me to suspect it as the root of the issue. But I just could not see anything amiss...until I took a photo. Can you see what it is yet???

(The next question - does anyone have a replacement they can flog me please?)

   

[Robert Foreman]

Looks like the anchor has snapped in two. 
  If it is the early Ruby type I have one here you can have.

[Nick Salmon]

Yes, that's exactly it.  Many thanks Robert.

[Reckless Rat]

Ouch!

[Ivor Hawkins]

Crikey, never seen one of those break, do you think the supercharger and the nitrous oxide injection, just proved too much for it?

[Nick Salmon]

You may well be correct Ivor!!!

[Nick Salmon]

Arrgh! Turns out the picture lied. The mount is in fact intact. Been under again this morning and can now see the 'break' is an optical illusion. So sorry to have led you up the garden path.

So now the hunt for the knock continues and I still cannot find anything obvious.

[Ruairidh Dunford]

It sounds like tooth damage on the pinion, or crown wheel.

You can inspect part of the crown wheel through the filler hole. Dump the oil and check for debris, too.

The pinion can be removed with the axle still attached to the car.

[David Stepney]

From the photos, the rear UJ looks not to be intact, although it might be the photo angle.

[Nick Salmon]

Diff oil (new before run to and from Beaulieu) filled with fine metal particles. Crown wheel teeth all damaged like this one. Oh dear.