hi, i recently had trouble with my gearbox on my 98 2.8 auto galaxy, the problem i had was it was messing about around 40 mph going in and out of top gear so i put it in a garage and asked them to change the atm fluid. all seamed great until friday, i was on a trip a the a12 essex when i noticed it was not going into top gear again, i see a parking lay by so i went to pull over and the car went down another gear or 2 so i knocked it out of gear and stopped. i noticed a burning smell and when i popped the bonnet there was smoke from burning oil then i noticed a puddle under the car. the AA picked up the moter and took me home saying the box had gone and it could not be towed. whe i got home the AA man asked me if i would drive it into my parking bay which i did with out any problem. Then on saturday i thought id take a look using the guide i have found on here, when i checked the level it come out of the plug telling me that the garage had over filled i think, i did not drain it all in case i was looking at the wrong thing. i then took the car for a short drive and kicked down and things and all seamed ok. when i got back i noticed a little seep of oil from the front of the gearbox sump. My question is if i replace the oil and sump gasket and filter do i need to use a joining sealicone on the gasket? i am hoping that all that has happened is that the excess oil has blown the gasket and nothing else, unless any body can tell me anythiong else that may have been done along with it. thanks in advance mark