Broken bolt

Dale c mi · May 20, 2015

First time on this site longtime yt,er. John Deere GT 235, 18.5hp twin.
The bolt that holds the mower clutch on the crank shaft broke off.
It is broken off about 3/8" up inside of the crank. ( the grass is quickly
getting tall) Thanks Dale

old · May 20, 2015

Left hand drill bit in the center as best you can and fingers crossed. Maybe an easy out of you get the correct type not the cheap ones from the hard ware stores. Problem is, is finding the good ones. I have a set of the good ones but they cost me $75 15 plus years ago

T.R.K. · May 20, 2015

Did you just find it broken or were you putting it in when it broke? It makes a difference. If it failed on its own there is a chance that what's left is not terribly tight. If it failed when you were putting it in, then its probably bound up in there somehow.

They have been drilled out and the hole re-tapped. Its usually 7/16-18 thread.

You may want to try a puncture wound punch at an angle going "out" first, you may get lucky.

I am not a big fan of easy outs. If you break one off in there you have a much bigger problem.

Jiles · May 21, 2015

(quoted from post at 00:30:43 05/21/15) First time on this site longtime yt,er. John Deere GT 235, 18.5hp twin.
The bolt that holds the mower clutch on the crank shaft broke off.
It is broken off about 3/8" up inside of the crank. ( the grass is quickly
getting tall) Thanks Dale

In manufacturing industry, I have run into similar situations many times.
In my opinion, the only way to "Professionally" remove the stud is to be absolutely certain you center punch and drill in the EXACT CENTER of the stud! Drill for the largest acceptable ezy-out and BEFORE BREAKING the tool, stop.
Drill the correct size for re-tapping and re tap threads.

Eric in IL · May 21, 2015

Always try the puncture wound punch method first, it just saves so much time if it works.

Then, in your case, it looks as if the threads in your crankshaft are relieved (gone/non-existant) down to the broken bolt. Use the largest drill bit that will fit in the hole to drill a center point in the broken screw. You are now very,very close to being perfectly centered for the ez out drill. I'd use a 1/8" drill first, then the size you need for the ez out. If you break the ez out it may be cheaper to trade machines at that point.

Greenfrog · May 21, 2015

I broke an easy-out off on a motor mount bolt once.. Not a good deal. Might soak it with penetration oil first, such a PB Blaster or Kroil. Drilling the right side hole for the ez-out is important. They wont take much torque.
Hold your lips right.
Good luck.

Broken bolt

Dale c mi

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old

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T.R.K.

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Jiles

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Eric in IL

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Greenfrog

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