Now then, now then....

When I went to buy my 850R, everything seemed fine. The seller had stated that the engine and gearbox were both "in excellent order with no clunks, rattles or smoke".

Soon after purchase however, I noticed a significant "clunk" when shifting the auto box from one direction to the other - particularly noticeable when putting it in reverse. It's sometimes also noticeable at low speed when I take-up or ease-off on the throttle. Otherwise, the box seems to be running fine in all settings.

I've checked the ATF level. I've even taken the somewhat odd precaution of pumping out 5L of ATF fluid and replacing with new (as I didn't have time or money to do a full change) I reasoned that some new would be better than none.

The paperwork that came with the car shows that the box was rebuilt (at a cost of £1578) in December 02, at 51k, after a persistent fault code from the speed sensor, which it says had been "worn away by a fault in the gearbox. (I suspect a previous owner was "reamed"!)

I'm no mechanic (but I'm learning fast) and am hoping it's just play in a CV joint, or some other linkage - and not the box failing again? Car had 124K when bought - now 131K.

What say you good people?