Welding Draft Arm

[Deere Dude]

Sadly I backed into a tree with my finish mower and broke my 3pt draft link, and worse yet I had to tell my wife. Regardless, I either need to buy a new one or weld this one up.

I could take the easy way out and just order one, but I want to try welding it. I wouldn't have a problem just sticking two pieces of regular steel together but am unsure about this type of material. It is some kind of casting and don't know the rods to use or even if it is a good idea to weld it.

I have 1/8" 7014 and 6011 rods along with a AC 240 amp welder. I planned on welding it together and use add a tab of metal on the back side. The bar is 3/4" by 2-3/8" and snapped cleanly. I am assuming to weld it I need to bevel it down all around and make maybe 3 passes.

Any tips as to the process will be appreciated. Welding skill is maybe hack to intermediate.



Thanks.

 

[stuckmotor]

This should be an educational thread when the good weldors come on.

 

[hosspuller]

Don't feel too bad about the damage. It was going to fail anyway. Notice the two rust marks at the break … Fatigue failure … The cracks would continue to propagate until the arm broke.

You might check the other arm at the same places for cracks.

When you try to weld it, preheat both pieces to 250 -350 degrees before welding.

 

[Deere Dude]

Don't feel too bad about the damage. It was going to fail anyway. Notice the two rust marks at the break … Fatigue failure … The cracks would continue to propagate until the arm broke.

You might check the other arm at the same places for cracks.

Actually I bent that arm about 5 years ago and straightened it out using a log splitter as a press, but it worked. The rust marks were ever so slight in relation to the thickness of it.

 

[RNeumann]

It should be a multi pass process after grinding both sides to a point making a nice “V” when the two pieces are touching. 6010/6011 passes with a 7018 cap weld is what I’d do........if I was welding it up- which I probably wouldn’t.

 

[Dneel81]

It should be a multi pass process after grinding both sides to a point making a nice “V” when the two pieces are touching. 6010/6011 passes with a 7018 cap weld is what I’d do........if I was welding it up- which I probably wouldn’t.

Agree. It's likely to not be stable after adding more heat to that area.

 

[Jeepnford]

Are you certain it's cast iron and not cast steel? You could do the spark test if you're not sure.

 

[RNeumann]

Are you certain it's cast iron and not cast steel? You could do the spark test if you're not sure.

I’m guessing (and agreeing with you) it’s weldable steel since it has other welds on it. They also sell just the ends that are made to weld on to your own link.

 

[yomax4]

Bending it and then bending it back tells me it's not cast. +1 on th spark test.

 

[pmsmechanic]

I've welded both arms on my 4410. They both broke through the lift hole. Welded with 7018 AC. No preheat. They haven't given trouble since.

I'm not a professional welder.... But I've done a lot of welding.

 

[dragoneggs]

It doesn't hurt to try welding it since as you said, you can always buy another one if you aren't successful.

When you do grind your 'V's in preparation for welding... weld the same day if you can, to keep the oxidation from setting in. I don't think most people appreciate how fast metal forms an oxide layer.

 

[Leejohn]

I would make a new one, might be easer.

 

[otlski]

I would overlap and weld reinforcing plates to bridge over the newly welded and ground repair area. It gets you greater cross sectional area in case your intended repair welds are not perfect.

 

[Jeepnford]

I知 guessing (and agreeing with you) it痴 weldable steel since it has other welds on it. They also sell just the ends that are made to weld on to your own link.

I had to weld a new top link bushing on my 3 pt. auger I bought for cheap. It came already V shaped so I ground a V on the top link bar and MIG welded it.

 

[Big Barn]

If you’re depending on it for a job or can’t afford downtime from another break, I would buy a new one. Then weld up the broken one with advice from the knowledgeable members here and keep it for a spare.

Either way you will have fun fixing it and probably gain experience and confidence. Win/win.

 

[pmsmechanic]

I would make a new one, might be easer.

I've often thought about making new ones. If I do they will be straight without the bend in them.

 

[RNeumann]

I've often thought about making new ones. If I do they will be straight without the bend in them.

Double HH Weld-On Repair Ends - Top Link

Have at it! If you look closely at the OP’s photos it looks like his might have weld on ends similar to the ones linked above. Several folks sell them. My local tractor supply store has several on the shelf.

 

[JERZEEFATBOY]

I would buy a new arm.
Several years ago I was working with a Danuser post driver. The previous owner of the tractor (who was a competent welder) had welded on new repair ends on the lift arms. While I was bending over to load a new post, a weld gave out and the post driver dropped, swung round and missed me by 1/2 an inch. The previous owner was an ace welder, but we all make mistakes and maybe the driver was just to top heavy . . . so, no welding on critical parts for me. (yes, I know, they can fail right from the factory . . . but I will take that chance more comfortably)

 

[Ritothebull]

I would just bevel it out and weld it with some 70xx grade wire as I have in the past, I don't know what grade of steel they're using on these but they are harder than mild steel and some are forged but they do weld nicely.

And I probably wouldn't reinforce it because you want the arm to fail rather than break the connection on the transmission housing in the event that there is another incident.

 

[Deere Dude]

I've welded both arms on my 4410. They both broke through the lift hole. Welded with 7018 AC. No preheat. They haven't given trouble since.

I'm not a professional welder.... But I've done a lot of welding.

It doesn't hurt to try welding it since as you said, you can always buy another one if you aren't successful.

When you do grind your 'V's in preparation for welding... weld the same day if you can, to keep the oxidation from setting in. I don't think most people appreciate how fast metal forms an oxide layer.

I would overlap and weld reinforcing plates to bridge over the newly welded and ground repair area. It gets you greater cross sectional area in case your intended repair welds are not perfect.

I would just bevel it out and weld it with some 70xx grade wire as I have in the past, I don't know what grade of steel they're using on these but they are harder than mild steel and some are forged but they do weld nicely.

And I probably wouldn't reinforce it because you want the arm to fail rather than break the connection on the transmission housing in the event that there is another incident.

Lots of good ideas guys. I am going in to town and will try to find some 7018 rods, grind the angle and try to weld it the same day. This is not where downtime is of the essence. I like the idea of putting a reinforcement chunk on it though. I would hate to have the arm break and no catch it right away and have my 900# deck or box dragging behind be and break the other side. I just need to be more careful and stay more aware.. I probably won't get to it for a few more days and maybe someone someone else might come up with a better idea. Either way, I am just glad the casting on the tractor didn't break.