Ford 4500 with a 755 backhoe, need a swing post, help?

[Plainjoe81]

This is the casting that connects the hoe to the tractor on the hoe side of things. Yes, it shows up on the New Holland parts list, but it's no longer available. Searched the national graveyards without luck. So, here I am looking to see if anyone has a machine that they are parting out, or if there is any sensible way of repairing it (it's cracked up the back of it).

 

[Plainjoe81]

... more specifically, it's part number 7706349.

 

[HardmanGT]

what is wrong with yours? You may need to repair what you have.

 

[Plainjoe81]

There's a crack up the back of the top half of this casting.

 

[Check Break]

Find someone locally who knows how to preheat and gas weld it. If they tell you they do something like, "they preheat in oven to 1100 F, gas weld with cast rod, bring back up to temp again and allow to cool slowly," they know what they're doing. If you post pictures of the crack, you'll get some opinions on the viability of a repair. If you don't repair and you can't find a used one, fabrication is another option, albeit a bit more expensive. Hope this helps.

 

[Welder Dave]

It's most likely cast steel and is readily weldable by an experienced welder. Cast iron isn't normally used where there's lots of dynamic and cyclic loading. Cast steel is used where it would be hard to fabricate a complex piece, like a swing post. Not really a do it yourself project unless you have a lot of welding experience. You don't want it to crack again. The crack needs to ground for a full penetration weld. 2-300 degs. preheat, welded with 7018, let it cool slowly and you're good to go. I wouldn't be surprised if other components are already welded to it. I wouldn't take a chance welding it with anything other than stick electrodes.
The boom is welded to the cast steel swing post on my Cat. It's never broke but I did rip the top swing pivot off that is plate steel. 2 1/2" pin and 1" thick plate the bushing goes in but only about 3/4" wider than the bushing on the side. Cat in their infinite wisdom put a 1/8" NPT grease fitting in the middle of the 1" plate. This took away about a 1/3 the thickness and is where the crack started and then continued all around the weld holding the bushing in. The bottom swing pivot is 1 1/2" thick and it bent as well. It's a good thing I'm a welder or I'm sure it would have cost a few thousand to repair. Mind you I spent even more doing the steering clutches.:beatsme

 

[Plainjoe81]

Good to know that a repair maybe an option. I will get a picture up later in the week.

 

[Check Break]

Dave's right. I screwed up here. The later Ford swing posts were cast steel so this one may be as well. If it is, your cost to repair will be minimal. It's still a good idea to post up some pictures of the crack from several angles so the welders can tell you how they'd stop it from running. You might want to check your boom for cracks also. They're cheap to repair when they're still in the formative stage.

 

[Plainjoe81]

Cracked swing post, Ford 4500 with attached 755 backhoe.

 

[Plainjoe81]

It's understood that welders would prefer a better view with more angles, but holding out until after the holidays before tearing it down (with a distant hope that someone has a part that they want to sell?). Meanwhile, I'll take any advise that's out there, thanks.

 

[Check Break]

Looks like there's a lot of wear on your pins. The swing post was probably slopping around and taking a beating, hence the crack. If the swing post is steel, I'd air arc the crack and weld it up. You won't know what the lower pin bore looks like until you remove the swing post. There's probably wear on the horizontal surfaces under the thrust washers also that needs to be built up or turned down. If you turn down you can replace the material with a thicker thrust washer.

From what I see, you're looking at new pins and bushings in addition to welding the swing post. The pin bore is probably in need of restoration which means opening it up and making a thicker bushing (if its not too far gone) or welding and line boring back to original dimension. The pin bores can be done by your local machinest or someone with a portable line boring machine.

 

[HardmanGT]

my guess is that you have another issue, too. It looks like the post has worn at the swing pins and the post is going to have to be sleeved to fix this. Take a look at how the there is a big gap in the last pic. In the second pic it looks like the top is tipping out pretty far

I had a similar issue when I bought mine. I removed it and sent it off to the machine shop to be bored out oversized and sleeved with thick walled steel.

 

[mitch504]

I had a good one, I'll look tomorrow or the next day and see if I have a good one.

The damn druggies have hauled most of the stuff I want to the scrapyards, (just trying to help me clean up)

 

[HardmanGT]

my guess is that you have another issue, too. It looks like the post has worn at the swing pins and the post is going to have to be sleeved to fix this. Take a look at how the there is a big gap in the last pic. In the second pic it looks like the top is tipping out pretty far

I had a similar issue when I bought mine. I removed it and sent it off to the machine shop to be bored out oversized and sleeved with thick walled steel.





View attachment 128432

 

[Plainjoe81]

The original plans were to replace pins and bushings (along with whatever was advised to be done), then found the crack. Also noted is the missing pin bolts. How big an issue were taking out those hydraulic lines? Things appear very tight in there.

Mitch504, I sure would appreciate you looking.

 

[Plainjoe81]

Great before shots HardmanGT, did you get any after?

 

[Welder Dave]

My Cat uses hardened bushings where the pins went through. Luckily they came out fairly easy. When I welded the top post back on and had to straighten the bottom mount, A 3" pipe was close to the same size to use as a line up guide for the holes. Then I got a piece of 2 1/2" heavy wall tubing turned down about .005 to use as a guide to make sure the upper and lower pins line up when the bushings go back in. I used a flap disc in a drill to clean the bores for the bushings after welding and then used some Loctite bearing retainer so the bushings wouldn't move. A tubing supply place gave me a 28" piece of 1/4" wall seamless DOM tubing when I told them what I needed it for. It cost $45 at a machine shop to have it turned down slightly undersized which was OK considering the tubing was probably worth that to begin with. It would have been a waste of time to weld it back together and straighten it only to find out the upper and lower pins were a little off and wouldn't go back in.

The crack in question in this thread has been there for a while. I can't tell if it has a bushing sized to fit the pin at the top and bottom of where the crack is or if it is one big bushing the total length. I'd guess the former. If that is the case, cut it out or machine it out and put a thick steel bushing the total length in. That would make the repair a lot better too. If you welded to the new long bushing when welding the crack up would add strength. It would be like a weld backing and you wouldn't have to worry about burning through. You could make a nice wide V where the crack is and fill it up with weld. You could still have it machined over size to fit hardened bushing in the top and bottom.

 

[HardmanGT]

Great before shots HardmanGT, did you get any after?

I was so happy to get it back from the machine shop that I forgot to takes pics. It has pulled a lot of stumps and rocks since then so the repair worked well

 

[Plainjoe81]

Any luck Mitch?

 

[Plainjoe81]

I hear that