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Quick Coupler Boss Welding

DSharpy

New Member
Joined
Jun 9, 2026
Messages
2
Location
Australia
Does anyone know where I can get working drawings/measurements for the quick coupler line boss mounts attached for a Cat 962M?
Would like to keep it as close to factory as possible.

Would I be right in assuming the round bosses need a weld all the way around and rectangle/square bosses just get welded vertical and gap filler horizontal to stop rust streaks like the grease line bosses?
liftarmas_page-0001.jpgliftarmas_page-0002.jpg
 

Simon C

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Jul 1, 2015
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3,065
Location
Rocky Mountain House , AB., Canada
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Heavy Equipment Mechanic
I could be wrong, but the square ones need to be welded on the horizontal with care taken not to leave a crater in the end of the weld by backing up 1/4 inch when you get near the end. Don't overweld as these things don't hold 5 tons of weight or force. Just silicone the ends of the blocks and paint over.
On the round ones I would just weld from 11o'clock to 1o'clock on top and fro 7 o'clock to 5'o'clock on bottom with no craters at end of welds. 7018 of some kind, not hard wire from a wire feeder which is brittle would be my choice. I would be using 3/32 rod only at about 80-90 amps and they will hold on well. Clean paint off welded areas first. The pieces will flex this way with the boom as it bends.
I am assuming this is a new casting and the blocks need to be installed.
Simon C
 

Nige

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Jun 22, 2011
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38,627
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G..G..G..Granville.........!! Fetch your cloth.
If you would like to post a Serial Number there is probably a detailed instruction with measurements, weld procedures, etc, for the installation of a QC. That will include the installation of all the blocks.

I could be wrong, but the square ones need to be welded on the horizontal with care taken not to leave a crater in the end of the weld by backing up 1/4 inch when you get near the end.
Agreed. Don't make any weld perpendicular to the lift arms. Weld the blocks only along the long side and if you like run the weld past the end of the block, curve it away slightly and tail it off to nothing.
 

Simon C

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Joined
Jul 1, 2015
Messages
3,065
Location
Rocky Mountain House , AB., Canada
Occupation
Heavy Equipment Mechanic
Agreed. Don't make any weld perpendicular to the lift arms. Weld the blocks only along the long side and if you like run the weld past the end of the block, curve it away slightly and tail it off to nothing.
That is how I was taught also. Have to allow for some bend and not create a pinch point that starts a crack.
Simon C
 

Welder Dave

Senior Member
Joined
Oct 11, 2014
Messages
18,049
Location
Canada
I'm not sure if loader arms are stress relieved from the factory like some excavator booms are? As far as welding it might depend on the heat input.
 

Welder Dave

Senior Member
Joined
Oct 11, 2014
Messages
18,049
Location
Canada
I could be wrong, but the square ones need to be welded on the horizontal with care taken not to leave a crater in the end of the weld by backing up 1/4 inch when you get near the end. Don't overweld as these things don't hold 5 tons of weight or force. Just silicone the ends of the blocks and paint over.
On the round ones I would just weld from 11o'clock to 1o'clock on top and fro 7 o'clock to 5'o'clock on bottom with no craters at end of welds. 7018 of some kind, not hard wire from a wire feeder which is brittle would be my choice. I would be using 3/32 rod only at about 80-90 amps and they will hold on well. Clean paint off welded areas first. The pieces will flex this way with the boom as it bends.
I am assuming this is a new casting and the blocks need to be installed.
Simon C
Could weld from each end and leave the final crater in the middle. I'm not sure if loader arms are stress relieved from the factory like some excavator booms are? Preheat will help reduce stress. Steel plate has the grain structure in all directions unlike flat bar or beams that have it in one direction only. That's why a lot small parts are made from plate rather than flat bar.
 
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