Firstfives.org

I have a parts car that I am trying to remove the output shaft from so I don't have to buy a new one ($450). The filister head screws are "really" locked in there and I am soaking the hell out of them with PB Blaster. They are 8 MM screws as far as I can tell? I tried breaking them free with a 3/8s socket wrench and pipe but no go. Wondering if an 8 mm impact socket would break them free? I don't want to round out the inside head of the fillister screw.
Any advice most appreciated.

Well i got the output shaft out.I got the filister head screws to move by putting a a floor jack under the breaker bar with the 8mm socket. Only rounded off two screw heads that I ended up cutting off. Are there no backyard mechanics on this forum or does everyone just take their car to the shop???

Nope, see to some of us rust is just a theoretical concept.

I have been known to resort to a Vice Grips on the head along with the socket at yards but I'm not sure that would have helped.

I think most of us work on our own cars.

What you did is what you needed to do. I would have used either an air impact wrench with a good tight fitting 8mm hex bit and cleaning out the inside hex first or even my old hit it with a hammer impact driver with a good 8mm hex bit. You could have used some heat. You could have used a chisel to hit the outside of the head tangentially to hopefully crack them loose. There are many ways to get the rusted stuck inside hex bolts off. I find the air/electric/ manual impact wrenches tends to be better to break stuck bolts loose than breaker bars and slow and steady leverage. I think I have stripped and snapped more things using hand tools than when using impact wrenches. No matter what the wrench, the most important thing is to have a good high quality tight fitting hex bit.

Walt B.
'80 528i

And the one ingredient we so seldom seem to have much of .... patience and time. Squirting penetrating oil repeatedly and over time makes a big difference. But who has time for that ????? I only learned this from necessity - I had only a few seconds a day to obsess over a stuck rusted bolt over the course of a week. A squirt here, a squirt there. Next think you know, you're talking real rotation. Of course I have a 4-foot length of pipe that slips handily over my 1/2" breaker bar.