D7 17A with 7A dozer Repairing brace on dozer arm

I was running the machine (D7 17A) today pushing some dirt for a road project. Then this happened. The brace on the left side of the dozer blade broke, I took it off and disassembled it. It appears somebody tried to weld it after a previous break. The root cause is that the brace tube is bent slightly causing uneven bending on the neck of the upper bearing.

Any thoughts on how to approach repairing this would be helpful. Any repair would have to address the bearing and the bent brace.

Photos below

Bearing shaft with attempted repair. Note that the shaft has cracks in it where it enters the brace proper also.

Bearing pocket

Bearing (broken from it's shaft.)

Arm Assembly

Hi, TOP.

Donchya HAY-TITT when that happens????

That parent metal appears SERIOUSLY crystallized. IF I am right, it would need some pretty serious cleaning up to get back to viable metal for welding. It might prove a better bet to cut away the cracked weld where that fitting is welded in to the tube and weld in a new end fitting - - - IF said fitting is still available. If it is not available, you might be better off looking for a good second hand brace or having a new fitting machined up to weld into the tube.

If you decide to go with repairing that one, a decent workshop with a decent hydraulic press might be able to press the bend out for you. That said, I suspect it take a pretty high capacity press to do it.

Just my 0.02.

Previous repair was a weld from what I can see of previous post weld cleanup. The construction of this piece from the parts book shows the stem/shaft going into the larger tube and then some kind of pin retaining it. Anyway, there appears to be another crack in the stem/shaft near where it enters the larger tube. My local used parts dealer, NorCan did not have it his in stock. I am asking around the area as there are people with parts machines. I posted here too for parts wanted.

The design is such that any small bend in the larger tube will put a tremendous bending stress on that stem/shaft if said bend is not in a plane perpendicular to the end pins. I can almost bet CAT used a forging there so welding would never work. There is a reason why the 7S used a ball joint there. The good news is the end pins were not worn. How it got bent is a mystery unless somebody had put a chain on it to pull the dozer out of stuck. The back side of the moldboard has numerous dents in it indicative of a pull with an excavator. The serial number is missing for that reason.

It was on it's way out when I bought it. Hard to turn through about 1/4th of every half rotation.

I wonder what some of the social media stars such as Isaac Cruz from the ICWeld YouTube channel would do, or Curtiss? from CEE Cutting Edge Engineering from down? Interesting damage there.

I would guess finding a used one from a salvage facility would be the most cost effective.

I watch Curtiss and his dog. He is good, but not in the neighborhood. Topper Machine has been another good one. People you can learn from. But ultimately it is the local shop (and they are also good) will have to do.

Just for my understanding, without a ball joint as the brace on a Cat straight blade has the threads need to turn if you tilt the blade? Since the straight blades have a ball joint, it seem odd they did not use on a angle blade.

This might be the time change to a hydraulic tilt. Would a hydraulic cylinder stand turning the piston in the barrel over the long haul? If you were to go to a tilt cylinder if your Cat system has no valve to run it add a 12 volt pump like snowplows on pickup trucks use. You don't need to move much oil. Check out Surplus Center for a short ram with large rod and have it welded into the current clevis fittings.

Where are you located? I have some braces that look similar. I am in Hudson Hope BC.

I would think that you could just remove the end from the Tilt arm and take the pieces to a machinist or a friend with a lathe and have them turn a new one. Then just weld it in.

Not being able to see the rear of that brace - is there any reason one could not weld "ears" on a heavy piece of thick walled tubing (petroleum well tubing as example) or an old shaft from Hydraulic cylinder and eliminate the bearing issue. The bearing was there to allow adjustment to the length (vertical tilt of the blade). That could be a fixed length, make it much easier to fix, just have to have the length correct. Granted, not original or adjustable but how often are you adjusting that length? - cts

Hi, cts.

The other end of that brace is a threaded with a threaded spigot screwed into it, which allows lengthening or shortening of that brace to tilt the blade by turning the brace, which is why there is that flat plate pivot at the top end of the brace.

I suspect that it would be possible to take out a lot if not all of the bend in the brace tube by doing a partial 'cut-n-shut' weld on the outside of the bend or an opposite 'cut-n-stretch' weld on the inside of the bend.

Which would then only leave the PROBLEM of the broken top end of the brace.

Just my 0.02.

It wouldn't be terribly hard to heat straightin the tube.

Probably better to Google it. I'm not really good at explaining things.

Deas, I understand the tube is the nut and the end fastened to the dozer push arm is the bolt ( 1/2 a turnbuckle so to speak). What I was trying to state, what is on the dozer arm end of that assembly that would allow the tube, bolt to be replaced with a yoke, and pin? Just trying to think of a "farmer fix" to get him running. - cts