I have a volvo v70 estate auto year 2000. I recently had the car serviced and the oil in auto box replaced with new oil. I was driving home from Marbella. when I heard a judder and warning light came on service transmission, shortly after that I lost gears and managed to coast in to a service layby. I let auto box cool down and after 4.5 hours I checked the level the dipstick showed box was full to the top of the stick. I have now had car taken to a garage close by and they checked oil level and confirmed it was overfilled. they then drained off 4 litres of oil which was cooked and dark in colour, they then tried running engine and gears no luck, they then put back 1 litre of oil and dipped the box showing the level was on the cool level of stick. the garage who serviced car are now disputing the video evidence I have and the 3 litres of overfill oil.
My question : what damage can overfilling auto box do to the box. your help appreciated. David

 

If the shop that you used the second time drained 4 liters of oil out of the transmission, then it was not overfilled. That's the approximate quantity of oil that comes out of those transmissions when you pull the drain plug.

If the oil that was drained was dark and burned, then that is because the remaining oil in the transmission was already toast.

Your transmission is nearly 20 years old. Have it rebuilt and go on with life. It was on its way out before you changed the oil.

You should apologize to the original shop.