Snapped mounting pin!!

[Unitt Boy]

Hi,

I've managed to sheer off the mounting pin on the right hand side (as you look at it from the back) of the PTO on my B8200, I've been to remove the plate that the pin is attached to but I'm not sure what to do next.

I've taken it to a couple of repair places who've said it would be better to just get a new plate with pin attached from Kubota. I called Ron Smith in Worcester who said that there aren't any in the country and a new one would be £120 +VAT, which is far more than I was hoping to spend.

In terms of repairing it I think that it just needs the old nut grinding off the plate and a new nut + pin welding on. Does anybody know if there's a welder somewhere (I'm based between Evesham and Cheltenham) who would be up for doing the job? Or I'm really just going to be better off biting the bullet and ordering a new one from Kubota?

Or does anybody know if there's another shop I should be contacting? or if there's a Kubota breaker out there somewhere?

I've attached a photo of the still intact plate on the other side of the PTO to give some idea what I'm talking about, it's only let me have a very low resolution picture but hopefully it'll help.

I only had the Kubota for about 6 weeks and so far it has been brilliant, i was just hoping it wouldn't get expensive so quickly!

 

[rmasonjr]

I have no experience with this, but that pin bears quite a bit of weight. I cant imagine a weld would hold. I'm curious what others would say.

 

[rentthis]

Looks like machine shop work to me. The original pin must have been welded. I would consider grinding is smooth, drill it, insert another pin and weld it. My main concern would be using the right steel for the job and having someone weld it that wouldn't weaken the pin.

 

[Unitt Boy]

I have no experience with this, but that pin bears quite a bit of weight. I cant imagine a weld would hold. I'm curious what others would say.

Yeah, I was inclined to agree with you but the original fitting was just a nut welded to the front of the plate and thats held fine (it was the pin that sheered off not the weld that broke).

I've just been to a metalwork place near my work, they've said that it looks like a standard pin and if I get a replacement one they'll grind off the old one and weld the new on in for £15 - £20 so I might just give it a go and if it doesn't hold THEN I'll think about spending £150 on a new plate.

I'm still very interested in what anyone on here as to say about it though.

 

[Unitt Boy]

Looks like machine shop work to me. The original pin must have been welded. I would consider grinding is smooth, drill it, insert another pin and weld it. My main concern would be using the right steel for the job and having someone weld it that wouldn't weaken the pin.

The original pin was threaded and screwed into a nut that was welded onto the outside face of the plate. About an inch of the tail of the thread was poking out the rear of the plate but didn't have a nut holding it in place, it just sits in a recess in the casting behind the plate. So I think if we grind off the nut that pin should come out of the hole in the plate cleanly.

 

[Diydave]

Not having a picture of the broke off pin, let me get this straight...

You have a pin snapped off, and a stub remaining in the still welded nut, on the back of the plate, right?

If that's the case, take the plate off, put it in a vise, and attach a pair of vice grips to the threads, near the outer end, and twist the stub out. You could also use a pipe wrench, to accomplish the same result.

 

[Unitt Boy]

Not having a picture of the broke off pin, let me get this straight...

You have a pin snapped off, and a stub remaining in the still welded nut, on the back of the plate, right?

If that's the case, take the plate off, put it in a vise, and attach a pair of vice grips to the threads, near the outer end, and twist the stub out. You could also use a pipe wrench, to accomplish the same result.

You're right, and I tried that last night, I put the stub of the pin in the vise and whacked the plate back and forth with a lump hammer but it didn't budge. I tried penetrating oil and heat too but no joy

 

[D2Cat]

Since you have access to the plate, welded nut and broken stud, mix a 50/50 potion of automatic trans fluid and acetone. Apply some mixture with a small paint brush and let soak.

If you can't get it free, drill a hole in the center (on the back side) of the broken stud. This will generate heat, relieve pressure and allow the stud to turn.

Next step would be to grind/cut off the nut and weld a new one on.

 

[ShaunRH]

Okay, you took it to a machine shop and they said weld it?

I have a very healthy respect for UK machinists, they are some of the most fussy, exacting sorts that you see in the entire industry, but if that's their solution, they're mistaken in this particular case if what I'm understanding about the setup is true...

If that pin is just screwed into a nut that is welded onto the surface of the plate, then the solution is to do the following:

Soak the threads of that in penetrant for a week, renewing the oil twice a day.

Heat the nut with a propane torch and reapply some penetrant (This will break up any thread-locking compound)

Using a left handed drill bit and a hammer drill, drill a hole about half the diameter of the pin in the middle. If you are lucky, the pin will back out all on it's own and you can replace with a new one, you're done. If not, continue with below.

Get an extractor of the 'hammer in' variety for that size of hole. They can be expensive but you drive them into the hole and they cut their own gripping surface as they drive in. You can then use a socket wrench to extract the screw. If this fails, you can apply some heat to the nut and try again to extract.

If all that fails, then you can grind the weld off of the nut and pop the entire thing off of the plate. Get a new nut and have it welded in the exact same spot and thread in a new pin. Some folks would say to do this first, and yes, you can, but this mean modifying the plate and subjecting it to fabrication processes again, something that has more risk assigned to it, so I would save it for last.

(LOL! Was typing mine it at the same time as D2Cat... he beat me to it in less words!)

 

[North Idaho Wolfman]

This is what your dealing with.

And this is what you need to fix it up. Give a shout if you can't find one locally, it would take a bit to send it to you but I have a bunch.

 

[Tooljunkie]

Yup, wolfman nailed it.
cut off damaged threads ( im assuming they are damaged now)
Grind welds holding nut
Remove nut
Remove pin from plate.
Forward mailing address to wolfman.
And emt him some money for shipping

 

[Unitt Boy]

Thanks chaps, I got the pin Wolfman showed and had it welded on to the plate, the repaired plate is back on the Kubota and we hooked the back hoe up again last night and it's held fine so far, going to give it a good few hours of digging tonight so fingers crossed.

Thanks for all of your help.