I've been driving my VW Bora for 7 years. Has had its regular oil changes, tune-ups, tires and brake changes. I love my car and want to keep it perfect. For the last 6 months I have felt that the automatic gearbox abnormaly changes gears. This happens after 10-15 minutes of regular soft driving. It is ussualy felt when changing from 2nd to 3rd, or 3rd to 4th, sometimes the revs go up to 3k and then I hear and feel a strong hit. I took my car to the dealership and they told me that the gearbox is sealed and that noone takes a look at it, this also happned on a Grease Monkey store, they dont service VW auto transmissions. Should I be worried about transmission fluid or something? Is there any place thtat It can be looked at? I think I have read previously about sediments but it seems to me pretty strange that this kind of service is not included. Thank you for your comments. Edit: 86K kilometers or 53K miles.