Ideas to un-stick pivot pin?

[tcmeyers]

On my BH70 backhoe unit (on Kubota B2601HSD) the large pivot pin (25 mm diameter) on the square tube that that sets the thumb position is stuck. That pin is supposed to be pinned to the frame of the backhoe arm with a small diameter bolt, with the bushing at the not-thumb end of the tube doing the pivot action. That bushing is frozen to the large pin. Forcing the tube to pivot only succeeded to shear the small bolt into 3 pieces. That makes the thumb usable now, but I’d like to fix it properly. Hammering on and drenching with penetrating rust remover hasn’t freed the pin from the bushing.

What should I try next?

 

[#40Fan]

You could try some heat, but I'd likely just cut the pin with a Sawzall.

 

[tcmeyers]

You could try some heat, but I'd likely just cut the pin with a Sawzall.

Heat the bushing and chill the pin. I’ll try. Maybe a heat gun and ice cube, before I torch the paint.

Sawing would remove some of the bushing but I guess I could even that up with bucket pin shims, or maybe ignore it, it’s just for positioning the thumb. Thanks!

 

[SDT]

Heat the bushing and chill the pin. I’ll try. Maybe a heat gun and ice cube, before I torch the paint.

Sawing would remove some of the bushing but I guess I could even that up with bucket pin shims, or maybe ignore it, it’s just for positioning the thumb. Thanks!

Heat gun will not suffice. You will need a torch.

You could try an impact hammer with an appropriately sized piece of hard bronze rod.

 

[85Hokie]

I had on exactly like this at a friends house - lots of liquid wrench (or whatever) and a BFH.

Tap on one end - then the other, and play the dance back forth song.

Rock the thumb arm as you oil and hit with hammer

It will move.

Heat will mess up things ......... not easily fixed!

 

[Caden]

Bigger Hammer.

 

[GeoHorn]

LUbricafte overnight… then a Port-a-Power to press it out. Your local body shop will have one.

In the future, grease it using Moly grease.

 

[Mowbizz]

Had the opposite problem when I first bought my thumb for my BX25D backhoe! The damned pin would not fit in the bushing! Hammering lubing, and finally I bought a cylinder hone to work the inside of the bushing…got it in but hope I never have to take it out!!

 

[Bisleybob]

Look into a ball joint press, I've used mine for stuck pins, works like it was meant for it