how to remove jammed screw

[steve_ma]

I did a dumb thing and somehow one of the screws on the stock throat plate wont come out. I have tried liquid wrench since yesterday....maybe it will cooperate after work today. The phillips head is nearly shot so I haven't got many tries left. I have no experience removing screws with destroying the hole. In theory, I guess I can tap into it in reverse and get it out that way. Can someone clue me in on what I need to do this or any other thoughts? Thanks for the help.

Also, if you happen to know the thread count, screw size off hand that would be helpful.

[eccentrictinkerer]

I've had pretty good luck using an abrasive disk in a Dremel tool to cut a deep slot in what's left of the screw.

You will probably cut into the adjacent plate, but at least you'll have the screw out!

[x00018]

The screw extractors from Sears work great.

[pelligrini]

I've had mostly good results with the screw out system. link

[Tom Slick]

you need an impact screwdriver



http://www.motorcycle.com/how-to/how...rews-3440.html

[Daryl]

Use a high-wattage soldering gun right on the screw. It won't get hot enough to melt the aluminum but will cause it to expand larger than the screw. After it is hot, then use the extractor.

[master53yoda]

Use a high-wattage soldering gun right on the screw. It won't get hot enough to melt the aluminum but will cause it to expand larger than the screw. After it is hot, then use the extractor.

This sounds odd at the first read due to heating the screw and the aluminum but aluminum expansion is way higher then that of iron and the hole gets bigger twice as fast as the screw does it works great. with aluminum nuts or bases it will release a screw that has galled sometimes. I have done it on my outboard motor bolts a few times.

I also have had good luck with the screw extractors. after every thing is removed you may want to run a tap down the aluminum threads and clean out any galling I also use a bit of never seize on some aluminum screws if I'm having this kind of trouble repeatedly, never seize has some clean up problems so don't use it if you don't have to. I do use it on all my outboard motor bolts though

[cgallery]

This sounds odd at the first read due to heating the screw and the aluminum but aluminum expansion is way higher then that of iron and the hole gets bigger twice as fast as the screw does it works great.

But, as the aluminum expands, won't the hole get smaller? And as the steel screw expands, won't it get larger?

I'd think heating the thing up would lock it tighter.

[master53yoda]

think about what happens to aluminum pistons in cast iron sleeves if you don't allow a little warm up time on diesel engines specifically you can seize them up because the aluminum piston gets bigger faster then the sleeve does. If you expand the metal around the screw it enlarges the hole not shrinks it. Heating a bearing allows it to fall on the shaft. the same applies here. try it and see.

[jackellis]

I did hte same thing and used a dremel to essentially cut off the screw head and then remove the shank with vise grips. Just took a little paint off the throat plate.

Replacement screws are available at your local hardware store. I forget the size but I had no trouble finding some.

[pelligrini]

But, as the aluminum expands, won't the hole get smaller?

Draw something in CAD then scale it up slightly, the hole gets bigger.

[cgallery]

If you expand the metal around the screw it enlarges the hole not shrinks it.

Won't the heated aluminum will expand in all directions, including towards the hole?

This was discussed here some time ago and I think the expert consensus was that the hole gets smaller when the material around it expands.

[LCHIEN]

But, as the aluminum expands, won't the hole get smaller? And as the steel screw expands, won't it get larger?

I'd think heating the thing up would lock it tighter.

Think of a thin ring. What expands most when it gets hotter? The circumference expands. This results in a equal amount of diameter expansion since C= 2 Pi D. If you do a finite element expansion, (in layman's terms, treat everything as a bunch of tiny pieces whose group behavior dictates the behavior of the large piece), that's what it'll do.

[Tom Slick]

This mad scientist demonstrates it well

http://www.youtube.com/watch?v=XMIsc5PbTiM

[MilDoc]

The screw extractors from Sears work great.

Gotta agree with that. Just make sure to follow instructions precisely.