Rounded bolt head

Went to drain transmission fluid and the drain plug rounded out. Must have been over torqued. Tried vise grips. Made it worse. Tried screwdriver and hammer. No effect. I guess you don’t have to have it out. Don’t want to make it to messy and spill the fluid all over driveway. Any help will be appreciated.

Year, make, model? Automatic or manual?

2003 chevy avalanche W/auto tranny The bolt head is reccesed the distance thehead is thick which makes it difficult to get a wrench on it. I had a socket and the edges of the head just rounded out.

Try a 6-point socket. It will hold much better than a 12-point.

Or drop the pan and have at the plug with a reverse drill bit and screw extractor.

Have you tried to use a socket the next size smaller (or maybe a next size smaller metric if this is standard) and tap it onto the the head of the bolt? Sometimes works for me, careful . . . tap it on carefully, and only a little smaller is enough . . get it on all the way too. Good luck! Rocketman

You weren’t using an American standard socket on a metric head by chance? Some will interchange but will not fit exactly and will round off bolt heads.
If the bolt head is not accessible to allow the use of a small pipe wrench then other methods such as welding a nut onto the bolt head, shaking it loose with an air chisel, etc. is about the only option.
If you’re attempting to chisel it loose with a screwdriver that seldom works since the screwdriver has too much give to it. You need a sharp chisel.

Didn’t you post in earlier about the dealer trying to sell you a trans flush? Anyway,the last thing you want to do is make a bad situation worse. Gonna replace filter? If Y, you’ve gotta remove pan anyway, so you could remove pan w/o removing drain plug. Get a wide drain pan and a transmission drain funnel to give a wide area to catch all the oil-will be atotal mess if you don’t. Obtainable at Pep,

Autozone. If necessary leave a few pan-to trans bolts loose w/others out and tap on side of pan w/wood block- hit block w/hammer- don’t go crazy. Eyeball old filter’s orientation, etc, so you can properly install new. Post back if you have more Q’s. Good luck and happy holidays!

Yeah Karl that was me posting about the filter earlyer. Gonna try it myself and the darn plug stripped out. Finally got it loose with hammer & screw driver and smaller socket (and a lot of cussing) that I drove on with hammer. After I drained it was not to hard to drop pan. Just bent shifter bracket out of the way. Got it back together and filled properly with no leaks. Saved a bunch of money. So glad I did not need the dealer. Thanks. This is one of the best foroms on the net bar none.

bwcarter-Fantastic! Just make sure you get it filled properly- my own car I let idle a good 45 minutes to make sure it’s really topped off. Yeah, this is a great forum and there’s techs here who know a lot more than me, too- you learn something new everyday. Thanks for posting back and happy holidays.

get large pan loosen up the bolts almost all the way out pry on sel and pan will drop to one side and fluid will drain not all of it. you can then drop it down from here. you can buy a new pan and put it on or fix the old one. you should may find toque spect and put the bolt in proper.