Cracked boom Takeuchi TB153

[suladas]

Noticed cracked boom has got a bit worse since I neglected to fix it sooner. Not sure the best course of repair? Just grind it out and weld it up? Should I remove the thumb mount to weld better underneath? The crack stops at the corner, the opposite side of boom has no cracks.

 

[heymccall]

New boom is $5108.38 UsD.
Perhaps used is an option?
I don't see any dismantled TB153FR on machinerytrader, though.

 

[Tags]

That’s the stick, not the boom, right? Probably need to gouge it out, reweld and plate it. Would not be good if it cracked all the way through and and it got twisted.

 

[PeterG]

Suladas as I also have a TB153Fr, I would like to inspect mine. Can you show a better image of exactly where that is on the machine? Anyone else ever heard of similar issues on the Takeuchi? Was your thumb mount OEM, or did someone else weld it on as an add on. Thanks. Peter

 

[heymccall]

We tore the bucket eye completely out of our TB53FR, and I replaced the stick (arm) rather than reinstalling the eye, as it also had cracked further up.

0396117950 long arm is $2600.63 UsD
There are several arms listed, though.

 

[Delmer]

You could just grind it out and weld it up. It will crack again eventually. You could improve the thumb mount, it will still crack again eventually. Don't want it to crack, don't use it so much, or so heavily.

So you could weld it the way it is, or fishplate the heck out of it, or replace it. Good and bad points to all. If you do want to fishplate it or change the thumb mount, post a picture of the whole thing and we can make suggestions.

 

[heymccall]

Only pics I could find of mine.

 

[PeterG]

Ouch. Mine is a 2012 with almost 1900 hours. I did just replace the thumb pin and bushing less than 70 hours ago. Do you think the machine is twisting a lot down there, or is it more internal rust or something else causing the issue? I will see if I can inspect mine later today.

 

[heymccall]

Certainly, on ours, it was all impact /abuse for our failures, not rust.

Yours wasn't rust, either. Yours was thumb stress plus improper welding to the structure. There are guidelines as to how to terminate the welds as to eliminate stress points, and, from that photo, those weren't followed.

I'll have to dig for instructions, but, I'm almost certain that the thumb ear plate shouldn't be the full width of the stick, either.

 

[uffex]

Good day
That looks like a thumb cylinder mount, correct me if I am wrong please.
Kind regards
Uffex

 

[suladas]

Opps ya it's the stick not the boom and it's at the top thumb cylinder mount. I first noticed it at least 2 years ago probably 600 hours or so, it's got a bit worse since then but nothing crazy. Even since then I worked the machine for like 7 hours today, probably an hour of it was hard digging and it hasn't got any worse, granted I don't want to use it again until it's fixed.

Buying a new stick isn't something I want to entertain, it sees maybe 250 hours a year and going forward I can see it dropping to 100-150. About the only abuse i've done is some side loading, other then that i'm pretty good but I do work it hard digging with a clean out bucket when I should be swapping in a tooth bucket. But 3000 of the 5000 hours on it were put on by previous owner so who knows, i'm sure it's been abused.

I wonder if pulling off the thumb mount and adding say 1/4" piece 12" long or so would spread out the force? Is it ok to weld up the sideways crack on the boom even though you're not suppose to weld across them?

 

[suladas]

Here's a few more pics of where it's at.

 

[suladas]

I found the pics I took of it 2 years ago. Definitely gotten a fair amount worse, but considering 2 years and say 600 hours without any fixing that it's only progressed that much, I can't see it taking that much of a repair to hold it?

 

[suladas]

Suladas as I also have a TB153Fr, I would like to inspect mine. Can you show a better image of exactly where that is on the machine? Anyone else ever heard of similar issues on the Takeuchi? Was your thumb mount OEM, or did someone else weld it on as an add on. Thanks. Peter

By the looks of it not OEM, the thumb was on it when I bought the machine.

 

[uffex]

Good day
I would suggest you address the cause first, that appears to be a cylinder mount that the welder did not finish. A coded welder will explain that welds should extend beyond the mounting plate and fan outwards. The cylinder mount is best removed and extended up the arm with proper welding termination. As a precaution I would also check if the cylinder has port rel;ief and that the adjustment is correctly adjusted.
Terminating the welding as the photo illustrates will cause a stress fracture across the arm.
Kind regards
Uffex

 

[suladas]

Got it tore apart, looked worse before doesn't seem all that bad now. I will definitely be checking the pressure relief once I figure out how. If that contributed to the issue it would be from previous owner as I am very careful not to attempt to push the thumb back with the bucket and always retract the thumb as I curl the bucket.

Few questions for repair, I know you're not suppose to weld across the boom, would that still apply to the crack and best just to leave it and put plate overtop? Should the plate on top be the width of the boom or narrower? I was thinking of extending it 6" past the crack on the top and a few inches past the cylinder mount on the other end, this would eliminate the need for me to make up a new plate for the cylinder mount and achieve the same result in spreading it out.

 

[uffex]

Good day
See attached may help.
Kind regards
Uffex

 

[suladas]

Good day
See attached may help.
Kind regards
Uffex

Thanks, helps for sure.

 

[tomo]

I've got the same machine with the same exact problem. Can you post some pics of your repair.

 

[Welder Dave]

You'll need to repair the crack first. Grind out about an inch past the crack to make sure you get it all. You need to grind a V with a 3/32"-1/8" gap at the root to get a 100% penetration weld. Start the weld at the end of the crack and weld back toward the side of the stick. Best would be to weld from both ends towards each other so all the weld craters are in the middle of the weld. A 1/4" or 5/16" oval reinforcement plate welded like uffex posted would add considerable strength. You want the cylinder mount in the middle. Preheat about 300F and peening the weld beads would help. If I had Mig, I would do a Mig root pass. Then use 7018 or even better 8018 to fill the V. Without Mig I would do a 6010 root pass. Some people have opened a crack up enough to put a backing strip in but a good root pass will full penetration is just as strong. You want an experienced welder to do the repair if you want it last.