Tractor Forum banner

1 - 8 of 8 Posts

·
Registered
Joined
·
317 Posts
Discussion Starter · #1 ·
Changing the spark plugs on Allis,the one in the Number 3 hole left the threads but the rest came out. I did an out standing job breaking a screw extractor off in there so now I have threads and a screw extractor in there. Now I need to pull the head, was wondering if I should continue to try and back the threads out with a new screw extractor??? Or should I try to screw it in to get them out??
Or just stop fooling with it and drill it out and retap the threads? I can drill to the correct size before it is tapped farily easy.

:D Find a new head? mine or the tractor:D :D :D :D ??????

:D Al
 

·
Premium Member
Joined
·
1,394 Posts
Well i f you broke of a screw extractor they can be a real bi%&h to drill, even with a drill press and ideal conditions....Usually it takes a carbide or cobalt drill and lots of pressure. When you say you left the threads, I assume you mean the plug itself left its threads in the cylindr head, and not the lower metal portion of the plug i broken. Big problem with thin sections and screw extractors is that they wedge if its too thin and actually get tighter the more you try and remove ythe broken part if it does not have substantial wall thickness left. If it was just the thrads I would have run a chasing tap in the hole. I think it can probably be remidied as long as you have access...don;t know about the extractor though, sa its just way too much mass to knock into the cylinder and then you would never be able to retrive it without removing the head. Metal shavings are not a problem as a little grease on a stick and some air usually gets most out, so tapping to clean up the threads is usually not a problem, and then just turn it over a bit without any plugs at all in it to allow the movement of the pistons to blow out the trash....If the heads threads are gone, you can always install a helicoil, again no need to remove head....


Tell me more about the broken extractor...........Is it the wedge with left hand sprial, or just a tapered square with flutes on the edges, or ???? HOw much of the extractor itself is in the plug hole and does any of it extend out the the top. Its possible to weld the shank end of a bolt to it, and turn it the opposite way in a lot of cases, but you have to be pretty steady with the welder. Stick or mig or better yet TIG would work. Usually extractors will break free by bumping with a drift punch in the direction (RH) to loosen them, and then finish turning it out with a needle nosed pliers....
 

·
Registered
Joined
·
289 Posts
If you can get the extractor out, I would recommend a combination of heat and penetrating oil on the remaining piece of the spark plug. I would get that piece red hot and soak it with the penetrating oil a few times then gently try another easy-out while it's still hot. If you have to pull the head, you should be able to knock out the extractor from the inside of the head using a hammer and punch.
 

·
Registered
Joined
·
518 Posts
alleyyooper if u can get it out with no problems n able to retap it you are in good shape i would try n get the extractor and the piece of plug out by soakin it and a little bit of heat
 

·
Registered
Joined
·
317 Posts
Discussion Starter · #5 ·
Thanks for the comments. Had already decided the head needed to come off so I had more room to work in there. Kill another bird with the same stone by doing a valve job at the same time if needed.
The extractor I know will come out by driveing from the reverse side as it is a straight flute job.

I like coca cola for loosing set up things. Dad taught me that one many years ago. Had a hub that wouldn't come off an axel even under 10 tons of pressure and heat. After socking for two days I slid it off bare handed.
:D Al
 
1 - 8 of 8 Posts
Top