When I rebuilt the boom/stick/bucket cylinders on my excavator a couple of years back, I resorted to making a custom 1/2" plate spanner wrench. It took a beating to get them loose, but did the job, and as far as I can recall, the one size fit all three of them. Now I'm up against two different sizes remaining to be rebuilt (blade & articulation cylinders) and I'd really rather not make custom spanners for them, too, but they're quite a bit smaller than the others. The only commercial spanner I tried was woefully inadequate. What do commercial repair shops use for this? Is there a ghetto method that's less time-consuming than burning more plate to make two more? Thanks - Dave
An air chisel will usually spin them off. On big cylinders I've had to use two at once.
Other than the pukka $100k dealer cylinder bench the good old plate spanner is the next best thing. The nice thing is you can blaze away at a plate spanner with an FBH and do it no damage at all. Approximately what size nut are you talking about..?
Two are 4-3/4", the other is 4-1/2" OD. I did spend too much time yesterday with an oversized one I'd made previously, cobbled up with a shim to try to force it to bear on the notch in the head despite being too large in diameter...probably took me two minutes after each sledgehammer blow to re-create the setup, what with chunks of 2x4 here, wedges there...I'd whack the crap out of the plate spanner, which ruined that 'setup' each time, and then take sad note that there hadn't been any detectable movement in the head position, despite a lot of force being applied. I finally got discouraged and tired, and gave it up for the time being, noting that I'd by then put a good bend in the 1" pipe I'd been using through the other cylinder pin-hole, to counter the sledgehammer action. I'd love for this to work, but worried I'd just ruin the few 'lands' available. Still, it's tempting. Maybe I should grind an extra notch or two just to give it a try. --Dave
Pin the rod end against something that will hold it or back on the machine and pull on a 4ft pipe wrench with something strong enough to turn it.
I tried an approach like this with the first of my cylinders a couple of years ago...HELLA torque, with a 10' cheater. The pipe-wrench handle began to deform, with about 400lbs of humans jumping on the end of the cheater. That's when I decided that impact would be key, and started making 'smack-wrenches' or 'smackable' spanners to deal with the immense torque needed...the impulse from being struck with a sledgehammer seems to be key. This time, laziness being the Mother of Invention, I decided to modify my old custom spanner by embedding a 5/8" nut in the arc, such that a grade 8 bolt threaded into it opposes the hook diametrically, making it ghetto-adjustable. I'm probably not the first to do something like that, but it saved me a lot of time that I'd otherwise have had to spend burning 1/2" plate to make one-off spanners, to suit two head-nuts that were awaiting some serious whacking. One STILL was extremely resistant. Hours of work later, I realized that because these two (blade cyl) had external threads on the cylinder ends, with heads threaded over the outside, I could probably do quite well by just heating the nut with a propane torch. Immense difference. I had the damned thing off 15 minutes later.