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Broken Quick Coupler

atgreene

Senior Member
Joined
Nov 30, 2005
Messages
508
Location
Sebago, Maine
My main bucket pin on the Takeuchi has had some play for a while now. I have greased it religiously, but assumed that the pin and bushings had worn with 1400 hours on it. The thumb also runs on the same pin, so last fall I tried to drive the pin out and had no luck.

The guy who built the quick coupler, main pin, thumb, ripper, clean-up bucket, skeleton bucket and hd digging bucket told me to run it for as long as I could stand the slop, as there's no point in replacing pins and bushings until they are completely worn out.

On Tuesday I finally found out that the bushings weren't worn. While cleaning up a jobsite with the clean-up bucket, the coupler suddenly tore free from the boom. The bucket and coupler hung from the dog-bone. NOT a good feeling.

I hauled the machine back to the manufacturer and with the aid of a cutting torch, they disassembled everything. The main pin was actually broken in two places, and had been for some time. One break was at a grease hole, the other inside the thumb bushing. On a good note, all the bushings were tight and full of grease. Evidently the reason I could not drive the pin out was because it was broken and was hiiting the bushings as I tried to drive it out.

The lesson in all this, just because the manufacturer says not to worry about something, don't hesitate to look into it for yourself. A broken main pin may not always present itself with the typical symptoms. The only way to have found it was to have taken it apart with the torch, and at the time, I went with his advice to run it, as everything would have to be replaced anyway.

I know some of the experts out there who have never broken anything will say I abused the machine, feel free to bash away. I just wanted to pass on my experience so as to help others avoid the same mistake.

BTW, the estimated repair bill is $2400.00
 

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Jeff D.

Senior Member
Joined
Nov 9, 2005
Messages
1,280
Location
MN.
atgreene said:
I know some of the experts out there who have never broken anything will say I abused the machine, feel free to bash away.
How about those of us who also break things, but just don't admit it publicly, can we bash away too?:D

Seriously though, sorry to hear about your problems atgreene. In the last pic it appears that the link hanging down got a bit of a twist to it also. Is it still straightenable, or does that need to be replaced too now?(too fatigued?)
 

Mike J

Well-Known Member
Joined
Aug 5, 2006
Messages
61
Location
Pa
When the thumb was installed a longer pin had to be used correct? Maybe the pin was made out of an alloy that was weaker than the factory pin?
 

atgreene

Senior Member
Joined
Nov 30, 2005
Messages
508
Location
Sebago, Maine
The guy who builds these has built hundreds, and I have faith in his product. I don't like the fact that the bucket, boom and thumb all pivot on that one pin. That is a lot of stress. I'm not sure about what he uses for materials in steel, but his employees told me that he has never had one tear off the machine.

I suspect that the pin broke in one spot way back, but the roll pin he uses to hold everything together helped keep everything in place. When the second break occurred, it began to wear-out the roll pin untill it let go.

As for the dog bone, he's repairing that. Said it would be less expensive to repair vs. replace, and stronger.
 

KSSS

Senior Member
Joined
Feb 27, 2005
Messages
4,336
Location
Idaho
Occupation
excavation
I have a similiar set up on my TK 153 and also had the same on my previous TB53. The coupler thumb all hinge on the front main pin. I traded my TB53 at 1500 hours and the 153 has 200 hours on it and have not had a problem (WerkBrau coupler/thumb). I would suspect that maybe the main pin was not up to spec at the time of installation. The fact that the pin broke in two places makes it sound like it was a brittle/weak pin to start with. The TK machines do make a lot of bucket curl force for a mini ex.
 

jazak

Senior Member
Joined
Jun 22, 2006
Messages
331
Location
NJ
That looks like really think metal to be using as a quick coupler, no?
 

CascadeScaper

Senior Member
Joined
Feb 27, 2005
Messages
1,162
Location
Lynnwood, WA
Occupation
2nd year Operating Engineer Apprentice
Our 303CR with 550 hours has some slop in the bucket pin only, everything else on the machine is tight. Makes me wonder if we're having the same issue, we grease religiously as well.
 

atgreene

Senior Member
Joined
Nov 30, 2005
Messages
508
Location
Sebago, Maine
Pull the pin and check it. Have some shims handy to reshim it when you put it back. It's well worth the time to save any hassle later.
 
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