Repairs LX188 pto clutch bolt coming loose

[deafvet]

This is the second time that this has happened, heard rattling noises while mowing and stupidly did not stop.
The mower deck quit cutting but engine still running. The 4 inch or so 7/16 bolt on the end of the crankshaft and its washer were gone, clutch dropped down. Couldn't find the bolt or washer in the grass where I had been mowing, they weren't on the deck.
Bought a genuine JD bolt and cup washer, cleaned and used Locktite. Torqued to about 50 ft/lb (estimate) but
don't see how to keep the engine shaft from turning when tightening the bolt.
Any ideas ?
Thanks.

 

[RoperGuy]

Remove your spark plug and feed in a few feet of small rope/cord and this will lock the cylinder. Remove when done

 

[deafvet]

Well, I should have checked further when the bolt fell out the second time.
I put in a new bolt and cup washer using loctite (actually used Permatex hard
gasket seal). Approx 45 ft/lb.

Ran for about an hour ok, then heard a bang so I turned off the mower.
I thought that the same thing had happened, but the bolt had sheared off in
the crankshaft, instead of just falling out.

Looking at the pto clutch, it seems that the bearing(s) are bad, the pulley has
quite a bit of wobble. That was probably the cause of the bolts working loose,
and later breaking when it wouldn't unscrew. I had noticed that the clutch
seemed pretty hot, but did not know what 'normal' might be.

Not sure what my options are now, since extracting the broken piece would be
very difficult.
Am thinking that welding a inch or two of 7/16 stud on the end of the crankshaft, (the broken end is about
a quarter inch inside of the shaft), then using a washer and nut to hold the clutch (a new one) on.

Does that sound possible or reasonable ?
Thanks.

 

[gainestruk]

I don't think I would weld on crankshaft, it could soften and cause it to break off, also you could get an arc inside engine causing damage, and possible electrical damage to ignition and charging.
Try drilling and ease-out.

 

[bertsmobile1]

Lots of options but all will be slow.
Drill it out using a good quality cobalt drill bit following up with eother an easy out or grind all the bolt out with a Dremel tool till there is nothing but the thread left and wind that out .
or
Spend a few more $ and buy a left handed drill bit, drill into the bolts with the drill in impulse mode or hammer mode if your drill does not have an impulse setting.
Naturally you use a drill that can turn counterclockwise.
If you heat the shaft to "spit boil" which will soften the Permitex most times the jerky left hand action of the drilling will unwind the bolt.
or
buy a new bolt, remove the engine and take the engine & bolt to one of the specialists that "disintergrates" stuck bolts, that will cost around $ 50 to $ 100 but will be the quickest.
Dont forget to tell them you used Permatex. Most of these companies use water drills and they are unbelievably accurate so will be able to remove the bolt right down to the bottom & not touch the crank ( voodoo engineering )

 

[motoman]

Assume Harbor Freight has stores there? Avoid a high priced L hand bit. HF has a nice 4 or 6 pak cheap and good. Use a variable speed reversible hand drill. GO SLOW AND ALIGN.

 

[mbrahmer]

So, what causes the bolt to come loose and shear? Bad bearings or what?
My X340 sheared the bolt today.

 

[mjb8fj]

So, what causes the bolt to come loose and shear? Bad bearings or what?
My X340 sheared the bolt today.

from my experience- all these are great tips the guys left here. the importance of going slow is key!!!! take your time or well, its costly. It gets boring up underneath there yes, but take a break and come back and continue going slow!
As far as what causes it, well that can be just the threads have gotten stretched over time, vibration.... and well the second time, again could be the threads have stretched and you couldn't get it tight. there is another possible cause of what is called hydro locked bolt from the locktite, which is another thread somewhere. When you get the old bolt out, blow the threads of that crankshaft with compressed air if you got the opportunity. We always do it there, and on head bolts. The extra time (what, 20 seconds?) saves you so much extra work! If you don't have air, we try to clean it out best you can with something like brake cleaner (carb cleaner will leave behind an almost Teflon type residue).