Broken hitch arms on a 3320

[Larry239]

How can some bend 4 inches and others break so clean seems like they would have to be made at opposite ends of the hardness spectrum. What type of non cast metals could break so clean? Can forged metal break like that?

Who knows!! I was watching over my shoulder when I hit the stump. I was in low gear with 4x4 engaged and traveling slowly. My tires had a good grip on the ground. When I hit the stump I saw the box blade move several inches to my right. At the same time I watched the lift arm bend like it was soft steel. The main radius of the bend is where Bsprings' arm broke.
Bspring hope your weld holds. Having to pay the dealer 245 for a replacement is a costly option.

 

[JB4310]

I don't think those butt welds will make that piece as strong as it was, not sure though. But if you want to go back to what you were doing, pushing the box, I would box that repair in with some flat or angle stock 8-10 inches long with full length welds. You could do that yourself with your mig, that might make it stronger than new.

Good Luck
JB.

 

[kennyd]

I don't think those butt welds will make that piece as strong as it was, not sure though. But if you want to go back to what you were doing, pushing the box, I would box that repair in with some flat or angle stock 8-10 inches long with full length welds. You could do that yourself with your mig, that might make it stronger than new.

Good Luck
JB.

The only problem with making them "stronger than new" is what then becomes the weak link? I'd suggest it would be the castings on the tractor that will be a LOT more than those arms.

Not using the 3PH in reverse to plow over trees is the real answer here

 

[JB4310]

The only problem with making them "stronger than new" is what then becomes the weak link? I'd suggest it would be the castings on the tractor that will be a LOT more than those arms.
QUOTE]

Yeah, I was thinking that even as I was typing the suggestion, I guess in this case the weakest link is the cheapest link. just don't think those butt welds will hold up, maybe not even to normal hard/heavy use.

 

[sunnyside360]

The only problem with making them "stronger than new" is what then becomes the weak link? I'd suggest it would be the castings on the tractor that will be a LOT more than those arms.

Not using the 3PH in reverse to plow over trees is the real answer here

I agree 110% with kennyd's assessment. This why I never back up with the box blade except to smooth out loose dirt and gravel.

 

[Dyer retired]

I snapped both of my lift arms in half using my box blade in reverse. I just read that itç—´ not a good idea to do that but it works really well until it breaks.

How well will it hold up if I weld them back? Has anyone had any success with this?

Bspring,

I bent my drag links a couple of times (slow learner) and ended up copying a solution that 3RRL suggested. I don't know how well you can see it in the picture, but I welded some square steel stock on the bottom of the drag links....like an upside down "T" and haven't any issues since. I exercise more caution also, but the hidden stumps under the snow will surprise you every once in awhile. If you searched "Box blading in Reverse" you'll see 3RRL's posts on lower link repairs, he has some better pictures of the repair. Dyer, retired

 

[sandman2234]

You guys are lucky! I tear up enough stuff without ever using my boxblade in reverse, so I can't imagine what kind of disaster it would be if I tried smoothing out something in reverse. Maybe this is why the cost of replacement used liftarms is so expensive. I need a set for my 7710, which has a boom mower on it, so the lift arms were removed by the previous owner. The company trashed the lift arms when they got tired of them setting on the shelf, taking up space.
David from jax

 

[Bspring]

It has been several months since the repair and the welds have held fine. I did not reinforce them because It should make me be a bit more careful and I do not want to break something more expensive next time.

 

[ddivinia]

The box blade is great for cutting saplings off level with the ground or on bigger trees it will rip it out by backing into it and lifting up. Anyway I backed into what I thought were a few saplings but it was a stump that they were growing out of. I hit it at an angle and both hitch arms snapped.

A welder instructor friend of mine is telling me that my MIG welder will not work for this project but I am tempted to try anyway. As can be seen in the picture I have already fixed one of them.

Buy new ones that have adjustable links and quit doing that stuff.

I was at the dealer the other day and some guy had a 5525 in there that they were backing into stumps with a box blade. It broke the rear case of the transmission...

D.

 

[Rob-D]

Those arms are intentionally the weakest link. I didn't Rockwell test the metal on my Deere OEM arms but they are welded and not cast. Could be plain old 1018 steel or something with a little more carbon like 4140 and tempered (axels are usually 4140) but whatever the case you don't want to break tranny housings or internal parts.
You can MIG them with a high carbon wire or use plain wire with tracks to spread the stress but that's as far as I would go.
Hobby welders won't do it even with gasless wire that has better penetration. You'll need at least a Miller 210 or something beafier in my opinion and like some people advised make good 'V's.

Rob