OHHH Snap

[woodlandfarms]

Well, pictures are worth a thousand words. The bottom knuckle let go today. The upside is I was not on the tractor, and the guy who was is a dozer mechanic, downside is, well, my tractor is broke in half. On initial inspection it appears that this piece may have been repaired in its previous life. It sucks. It is a tough weld but my neighbor who is a great mechanic wants to tackle it, and I will be glad to pay him.

But beyond this break is the break on the chasis. I am not sure how, what, when, why. The break looks old but I have to say I don't feel I have seen it before. Anyway.. Calling PT on monday to order a new knuckle. Will discuss all the issues with them then.

Any thoughts btw

 

[Lil_FarmerJim]

I'm no PT expert, but that doesn't look good. I assume this is the pivot point? If you got it used, I would say there is a good chance it did this once before.

Here's hoping its not a difficult fix.

 

[Clumber]

Wow, that's tough luck. Hope it can be repaired soon!

 

[J_J]

Carl,

Did you not hear the two halves anything banging before it separated? I would have the welder insulate those hyd hoses before welding. If there is any hyd fluid in that area, it should be thoroughly degreased/cleaned. Make sure he has insurance.

 

[MossRoad]

Ouch!

My condolences. Makes me want to go out and inspect my center pivot right now.

 

[ponytug]

Dear Carl,

Sorry to see that this happened. Some fraction of the knuckle is a bolt on part. I can't quite tell in the photo what broke.

The second break looks old, judgeing both from the crack and the wear on the bolt. The bigger question would be why it failed there. Unlike the knuckle, it is not an obvious stress point.

All the best,

Peter

 

[woodlandfarms]

So, we are getting into the whole deal but here is the long and skinny

130 for all the parts (including new spacers). Terry says that is an uncommon situation, but not unheard of and they have fixed this many times. Simply grind off, weld on the new one.

It is a collar that failed. The feeling is that the tractor never had the jesus nut tightened by the previous owner. It was stretched out under his lack of maintenance and this was just inevitable. The broken front has to do with this piece failing. Terry thinks that it broke maybe a while ago and did not come completely apart. That the bar that holds the two haves together was over torquing and cracked the front.

Anyway, ordered the parts. Will let you all know how it goes.

Carl

 

[Johnbro]

Well $130 doesn't sound like too bad a hit (like a tank of diesel:laughing so I hope you get it all back together for not too much money or inconvenience. Let us know how it goes and take lots of pics!

 

[KentT]

My 425 had been "broken" there by the previous owner (PTRich in the archibves here) and repaired. He got it stuck up to the bellypan in muck, and broke it pulling it out. However, there were no stress cracks to the front (or rear) parts of the tub -- the "Jesus nut" coupler simply ripped out of the front half of machine. He ordered a new coupler and had it welded in. That repair is now 5+ years old and 400 hours old, and still is in good shape. I try to check and tighten the Jesus nut now on a fairly regular basis.

I think I'm getting wear on the front joint for the "oscillating" top bar now that will have to be dealt with at some point...

 

[woodlandfarms]

If you have pix I would take them on your situation.

And an explanation for the Jesus nut comment. It is a term used by helicopter pilots (I do a lot of work in helicopters for my business) and the older birds, especially huey's have one nut that holds the top rotor in place. It is called the Jesus nut as, well, it it comes loose while you are up in the air you probably will meet your maker if you believe. It is the only word I have ever been able to come up with in explaining the connection on the PT.

Carl

 

[J_J]

Jesus nut. Not all helicopters have them.

Jesus nut - Wikipedia, the free encyclopedia

 

[KentT]

If you have pix I would take them on your situation.



Carl

Sorry, as usual I don't have any good pics of the repair and the machine is 900 miles away. Talked to my friend there today, coincidentally, and he was using it clear fencerows... he's used if far more than I have...

 

[MossRoad]

Jesus nut. Not all helicopters have them.

Jesus nut - Wikipedia, the free encyclopedia

It figures there'd be a Wiki page on that! :laughing:

When I worked at the airport I was over near the shop and a mechanic came out with a crescent wrench that was every bit of 5' long. I was stunned by the size of it. I asked him what that was for and he said the Jesus nut on a helicopter. Of course, I had no idea what he was talking about, so he explained it as such (not direct quote, but close enough for story telling):

"This is for tightening the one nut on top of the helicopter that holds the rotors on. If it comes off, you are going to meet Jesus."

My jaw dropped.

Never thought of it that way before and have always thought of it that way since! :laughing:

 

[Gravy]

If I were Jesus, I wouldn't be very pleased to have my name associated with a zero-redundancy design of a survival-critical system. Some engineers and accountants would have some 'splaining to do.