My backhoe thumb cylinder evidently needs to be resealed/repacked/rebuilt, because it is leaking around the rod. I am not going to try to fix it myself, but I obviously need to get the cylinder off of the machine. This is not a factory installed thumb, but was added at some point by a previous owner. It appears that the pins were driven into place, and are very snug. My question is how does a guy go about removing this type of pin. BTW, I do not own a torch. As can be seen in the photos, there is no way to get to the one end of the longer one. Suggestions?
Have you tried beating on the tapered end with a BFH? I would be careful not to flare any part of the large part of the pin.
Yeah, I gave it a few good hits with a big sledgehammer, but it didn't move. Also, as you can see, there is no way to get a direct shot at the end of the longer of the two pins.
Try drilling a hole through it and put a grade 8 bolt through the pin to pry against. You will probably want to replace the pins with floating pins that are held in with cotter pins when you go back together.
You might not own a torch, but I’m sure you have a propane one aka the one with the blue bottle. All it takes is a little heat. You don’t need a whole lot to get pins moving. Not saying this will work but it’s worth a try.
Something surly must be keeping the pin in place. I would look for what that is, and remove it. As a last resort, I would sawzall on either side of the cylinder rod eye. At that point the cylinder would come out, and leave you with 3 less stuck parts to get out. A porta power would help at that point if it is that tight. If it is a bugger, I would leave the barrel end in the machine and break the gland nut loose and dissemble the cylinder and take that part to the hydraulic shop, if you do not want to do it yourself. Again, I feel like the pins would have walked out long ago if something wasnt securing them. You need to fine that first then proceed. A setscrew is a possibility.
In addition to what others have recommended, my approach would be to: 1. Clean it up so I could clearly see what I am dealing with. (especially looking for some sort of retaining pin or set screw) 3. Make sure there is no load or pressure on the pin 3. Go a couple rounds with the BFH. 4. Heat it up and go another round with the BFH. 5. Try and get a small pipe wrench to lock onto the long end of the pin close to the cylinder. Try and twist it to help loosen it. (Even a small pipe wrench with an equalizer could help loosen it up). After that, I'd have to think on it some more Please let us know how you get it out. R
In some ways this thumb is very well designed, and in other ways not so much. There is no provision to lube anything, and the rod end of the cylinder has about a 2 inch hole where about a 1 inch pin goes through. The other end seems to fit well, but like I said, no provision to lube it. This is an occasional use farm machine, so it is not something that urgently needs to be fixed. It still works fine, but drools. I won't have a chance to work on it until at least next weekend.
When pins are stuck that tightly, beating on them with a big hammer most likely will swell the pin and make a bad situation worse. Without having a torch of some type makes the project a little complicated. I would suggest removing the pins from thumb. I mean where it attaches to the hoe. Unscrew the cylinder gland and then take thumb, the rod and gland to hydraulic shop and have them repair it. They will have the tools and knowledge to detach the thumb from the rod. Leave the barrel on the backhoe and just leave the stupid pin in it. Wrap the rod to prevent any damage to it.
I hadn't thought of that. You may have come up with the solution!
Tinkerer has a good idea there! Just be careful not to get hurt...it will be awkward and heavy!!
Yeah, that thumb is very stout, and is likely quite heavy.
A come-along or better yet an engine hoist will make it easier and safe to lower the assembly after unscrewing the gland. Hook onto the thumb and gently lower it. That way you have complete control of the rod when it seperates from the barrell.