A8 auto problems

[siwil1]

My co director has a '99 (3.7 i believe) A8 and is having probs with the Auto transmission, It appears to be thumping into gear and the seems to drop and stick in a lower gear.

It appears to resolve itself for a while when ignition is switched off then on again.

I recommended he had the fluid changed to see if that helped but unfortunately it hasnt.

I did try a search but didnt seem to be working so sorry if a common question.

Any ideas or is it a costly new box?

[AndyS2]

A new box will probably be more that the car is worth, check here for a ood used one:-

http://www.a8parts.co.uk/