753 Quick Tach pins lifting under load

[Unicam]

I'm almost done building a skid steer backhoe arm and during testing i noticed when i'm pulling back or curling the hoe bucket the attachment plate (store bought 5/16) is pulling away and against the angled part of the pins forcing the pins to lift up, about coming out of the attachment. it looks like the springs are too weak or something but everything is in working order.

has anyone noticed this? i've never really had occasion to put those pulling forces on the pins except maybe my stump bucket while prying down, but i'd like to hed off a potential problem as there isn't much of the pin holding it


messing around with it, applying pressure then letting off over and over, i can see the spring collapsing but the handles never move, it's all in the spring. maybe shim it with washers?

 

[Doughknob]

Well, maybe ‘someone’ will have a clue what u r talking about without pics……

 

[5030]

My ATI 'cams over' when engaged. They never move at all.

 

[Unicam]

my handle cams over and snaps down, and stays fully down. the wedge assembly fully protrudes out the bottom of the attachment, everything has worked fine for years but i've never pulled out on the bottom with the boom up to notice this issue. I didn't think mine moved at all either but now it's an 8' lever trying to peel the attachment away from the bottom, maybe it's fine, idk but the angle on the wedges against the attachment is forcing it to slide up and are barely hanging on when i pull back. I feel like it's either going to bend the wedges or bend the attachment and pop it off.

maybe tomorrow i can try to make a youtube video or something.

 

[Xfaxman]

Add a stop block above the latched rod so it can't be forced up:

 

[timbatrader]

When I had an old worn bobcat years ago I had a similar problem tried building up the worn areas with wield but still had problems since I weren't changing implements often the easiest option for me was to drill a couple of holes through bucket and mounting plate and put bolts through
It took a little longer to change implements/bucket but took all the slop out and stopped the bucket coming off at inopportune moments

 

[Unicam]

Thanks for the suggestions, I do change attachments quite often, i'd rather keep it as simple as possible but if i had to bolt it i could. maybe i could weld in some stop blocks. i don't have the exact same setup as xfaxman, mine has the allen bolt going down into the block but i like that idea. i almost need a 2nd person to move the machine so i can see exactly where the slack is coming from.

so in the vid it's just at idle, i'm not using the hoe, just pushing on the ground, pulling back the left stick. if i were to really rev it up and reef on it it pulls the pins up even further. at the end of the video, i'm trying to show the handles seem to work fine but can easily be lifted.

 

[Xfaxman]

maybe i could weld in some stop blocks.

Another view of a stop block:

And how much your pin moves in your video:

messing around with it, applying pressure then letting off over and over, i can see the spring collapsing but the handles never move, it's all in the spring. maybe shim it with washers?

But it might be harder to latch.

 

[Unicam]

thank you for the info, it's got my brain on track. haven't had a chance to work on it but i looked it over good and plan to weld in plates. it's possible my springs are fatigued as well cause when i tap on them they sound flatter than i think they should.... but i'm going to start with the stop plates

thanks for the help

 

[LD1]

I'm surprised on a skidloader that there aren't already stop blocks. Skidloader do alot of backdragging.