Help removing bolt from crank of a special tractor

I'm down to two main mechanical problems, charging (need gen rebuilt, everything else electrical replaced) and I need to completely go through the clutch assembly. But I can't get the bolt out of the end of the crank. I'm going out every night and PB Blasting it, tapping, and putting some torque on it, but it hasn't broke loose yet. (I don't currently have a torch.)

My question is, how strong is that 3/4 bolt from JD? Is it hardened? Is it prone to twisting off? I of course don't want to put alot of torque on it if it's a soft bolt. The clutch was never covered and the tractor always sat outside so it's pretty rusty (everything is pretty rusty...).

Thanks for you help, and this board.

Sorry for the length of the note.

Scruf

thanks,
scruf

On removing such a tight bolt, if you have an air impact wrench, first be sure and use a good 6 point socket so you dont round the hex and if its adjustable torque or you can lower your air pressure input, I would start at not too much presure or force and let it vibrate her a while, gradually increasing the torque.

If you dont have an impact wrench, I still think shocking blows and vibration is the answer as opposed to a long leverage cheater on a wrench usign a dead pull. Again, use a 6 point socket and with it held tightly in and against the bolt, I would hammer the wrench end with good sharp heavy blows to try and get her free. I dont think any sort of penetrating oil is gonna get in there and help much, and if you have access to a torch, dont heat the bolt so much as that softens it, but (in theory at least if you could get to it) if you can get heat to the crank area surounding/embedding the threads, the expansion and contraction might do the trick, however, there should be a washer there and you cant really get to where you need it. If you do heat the bolt, let it cool before you go back to work so its not heat softened. Good blows on the bolt head can help shock it loose, but dont mess up the hex.

God Bless, Ol John T Nordhoff in Indiana

I'll try my 1/2 inch air impact with an 1 1/8 6 point impact socket tonight, set low, and let it hammer for awhile. I have air tools, but rarely use them. The bolt head doesn't have any markings so it's probably a grade 3. I was hoping it was an unmarked grade 5 or 8. Sounds like twisting it off isn't common though, which is what I was hoping to hear.

I'm really glad I found this site and people that can help!

I'll post back when I get it off and I'm on the next hurdle.

Thanks,
scruf

The parts book does not say it is anything but a machine bolt. Can you see the marks on the head to determine what the grade is ? If you can mark it with a chisel, it's probably pretty soft (like a grade 3).

I can't say that I've had any problems getting one of those bolts out. Get a proper socket on it so it doesn't strip. Some folks like to use an impact hammer, and let it hammer for a while so you get lots of shocks, and not one long grain-straining pull, which is where you twist a fastener off.

Also, if it's soft and you twist if off, it will be easier to drill out. If it's hard, it ought to stand the torque.

Frank-in-Tallahassee
70D // 855