Broken bolt problem - JD 850

[lizardman]

The bolt that holds the footrest to the frame of my JD 850 sheared off. I didnt hit anything. It just broke. In the process of trying to remove the broke bolt from the transmission housing on the frame, I have managed to break off an easy-out in the broken bolt. Drilling into a case hardened easy-out is virtually impossible.

What in the world am I to do now to get this bolt out!?

Rod

 

[tcartwri]

If it's a blind hole, you can blow it out with a cutting torch. If the hole passes into the transmission case.... could be fun.

 

[Kernopelli]

You can try placing a nut on top of the broken bolt and welding it to the bolt. If the bolt is broken off at the top of the hole with no exposed threads, it should be easy to only weld the bolt and nut material. The heat alone will likely go a long way in loosening the bolt. There are ways to do it if the bolt is broken off below the hole's surface and threads are exposed too. Google "remove broken bolt with welding" and you'll find lots of tips on how to do different techniques.

 

[lizardman]

Thanks for the quick replies. The blow torch woulda/coulda been exciting, but I passed on the idea. The bolt and easyout broke off recessed within the screw hole, so it wasnt possible to weld to it.

So, I found my grinder bit and went to town on it with the air grinder. I got just enough of the broken bolt out to release the easy out(its hardened so the grinder didnt like it too much!). Soon thereafter the broken bolt came apart and then out. I will have to tap the hole for a larger bolt, but it is out.

And, at least there is not transmission oil all over my shop floor!!:laughing:

Now to find a tap. Hmm

Thanks,
Rod

 

[Danno1]

.


A little late w this reply but, Easy Outs are made of very hard brittle steel. Sometimes you can shatter them out w one of those spring loaded center punches.


.

 

[Soundguy]

ps... just because the bolt was recessed into the hole doesn't mean you couldn't weld it out.

I had a 1955 ford 950 come into my shop with 30-40 broke bolts and studs.. the welding trick works.. just have to play it differently.

PS.. if you don't want to tap to a large size, tap for a pipe plug, install, then drill that pipe plug for the oem fastener size.

soundguy

Thanks for the quick replies. The blow torch woulda/coulda been exciting, but I passed on the idea. The bolt and easyout broke off recessed within the screw hole, so it wasnt possible to weld to it.

So, I found my grinder bit and went to town on it with the air grinder. I got just enough of the broken bolt out to release the easy out(its hardened so the grinder didnt like it too much!). Soon thereafter the broken bolt came apart and then out. I will have to tap the hole for a larger bolt, but it is out.

And, at least there is not transmission oil all over my shop floor!!:laughing:

Now to find a tap. Hmm

Thanks,
Rod

 

[tmajor]

Also, keep in mind "heli-coil" thread repair.

 

[kennyd]

Also, keep in mind "heli-coil" thread repair.

That's what I was thinking, that way the stock bolt size can be re-used.

 

[Soundguy]

yuck... thread inserts are last ditch efforts as far as I'm concerned. I'd go standard fastener size thru a drilled out fastener if it were me. that's a common fix cor a block deck.. drill for a plug of other material stock.. lock it in, then drill that material for oem threads.

soundguy

 

[Kyle_in_Tex]

Here's what you can do.

1st, don't attempt this without adequate safety protection. You need full covering goggles, leather gloves, and I recommend a face shield and some old clothes with long sleeve shirt that you can throw away when done. Also put a tarp on the floor below your work area.

Get yourself a pneumatic die grinder and some 4flute carbide endmills. Either 3/16 or 1/4" diameter. Get at least 2 or 3 while you are there as they will chip/break down pretty fast. This will make a mess of small needles and metal dust but will cut through the easyout relatively fast. Try to hold it tight/firm so it doesn't bounce around. Be very careful to wear the safety protection as the endmills can shatter. Don't push them hard, let the sharpness do the cutting. Try to cut away the bolt only leaving the original threads. When you get down to just the shell remainder you can sometimes unthread it or get a chisel point and collapse it or even pull the threads out like an old helicoil.

I had to do this in a gravel driveway at night in a overhead position. Actually I was lying on my back. What a nightmare. I had to get a 25mm bolt out. That's about an inch in comparison.