joea99
Platinum Member
Swing cylinders leaking on the BH and finally getting around to resealing them. While pulling off the "support" (the top pivot point for the cylinders) the bolts were very reluctant to come off. Made sure there was no stress on the bar or cylinders to cause that. All four of them were arguing the whole way out.
Seems every one had "galled" in the support bar (blind holes). The part is 75586-14110, item 110 in the parts diagram of the swing cylinder.
The bolts are pretty much toast, I could not clean them up with the thread restore dies I have, it just tore them up worse. The threads in the support bar are more or less "gone" on two holes (still there but pretty much useless for holding IMHO), the other two are acceptable. None of them resisted the thread restore "tap" I ran all the way down.
Asking for opinions on reusing the support bar as is, finding some way to restore full threads, or just buy a new one (about $120). I realize it is pretty hard to judge something like that from my description, but don't think pictures are possible.
What I cannot really grasp is how those could be galled like that. The bottom threads are fine which says to me they galled on the way out. I get how that might happen if the bar was "cocked" while taking them out, as if the weight of the boom was on the cylinders, but the boom ends were already out and quite free to move about and I doubt the first one would have been affected in any case. If they were installed wrong, I'd expect them to be galled all the way down the hole. I've seen that sort of thing with steel into aluminum, but never steel on steel.
Thanks for any wisdom.
Seems every one had "galled" in the support bar (blind holes). The part is 75586-14110, item 110 in the parts diagram of the swing cylinder.
The bolts are pretty much toast, I could not clean them up with the thread restore dies I have, it just tore them up worse. The threads in the support bar are more or less "gone" on two holes (still there but pretty much useless for holding IMHO), the other two are acceptable. None of them resisted the thread restore "tap" I ran all the way down.
Asking for opinions on reusing the support bar as is, finding some way to restore full threads, or just buy a new one (about $120). I realize it is pretty hard to judge something like that from my description, but don't think pictures are possible.
What I cannot really grasp is how those could be galled like that. The bottom threads are fine which says to me they galled on the way out. I get how that might happen if the bar was "cocked" while taking them out, as if the weight of the boom was on the cylinders, but the boom ends were already out and quite free to move about and I doubt the first one would have been affected in any case. If they were installed wrong, I'd expect them to be galled all the way down the hole. I've seen that sort of thing with steel into aluminum, but never steel on steel.
Thanks for any wisdom.