Curious if someone see's something I don't in these piston pics regarding the nut. The manual doesn't say anything other then "remove nut". My 3/4 ratchet broke at the socket after apply about 500 pounds of pressure with a 10' cheater bar. I see some blue thread lock but that shouldn't matter with the amount of force I've applied. There's a small hole next to the nut but I don't see any screw/hex in it. This is the swing cylinder from a JD 310C....I've read mix results regarding applying heat so not sure if that's my next step. Any tips would be great
that appears to be a Nylock nut not threadlocker, which by all means is a one time use nut in that application, if someone took it apart before you and applied threadlocker to it, you are probably going to be forced to use some heat. I personally wouldnt touch that with a hand tool it would be a 3/4 or 1 inch impact for me ,hyd piston nuts usually have a fairly high torque spec which makes them that much more difficult to get apart
I would start with a 1" drive sliding handle and a 20' pipe if it was me doing it. I've never seen an impact wrench that can develop the torque that I can with that combination. I have done a few by using a hoe to pull the handle. Most hydraulic shops use a cylinder bench that turns the nut with a hydraulic cylinder. Those are capable of many thousand foot/lbs. It wouldn't surprise me to see a breakaway torque near 5000 ft/lbs.
That nut is tightened to 950-1100 ft lbs, you can put a little heat on it but you are going to need better tooling like a 4x1 multiplier or find a tire service truck with a 1" air gun to spin the nut off. Slide a 6' pry bar or a heavy pipe threw the eye and hold on as he hammers away. Still may need a 4x1 with a 1200 lb limit due to most 1" guns are worn and can't get it. You may find a equipment dealer close by that would break it loose for you also.
Thanks Walkerv/Mitch Upon further inspection I agree its a Nylock.....That would explain why my 3/4 snapped....I wonder if this is a standard bolt JD used or an add on by previous owner.
sheepfoot posted the tightning torque so after seeing that you will probably have to have some 1 inch stuff as mitch said with a monstor cheater bar, I have done similar on a bigger cylinder that involved a 48 inch pipe wrench 10 foot of pipe and a backhoe to push it with an excavtor parked on the rod eye to hold it. ended up taking that particular cylinder to the dealer to have it retightned as we didnt have anything at the time to do it rite
It's not that big of a piston nut. I'd say that a decent 1" impact would pop it right off. Cut a wrench out of 1" plate if needed and add as much cheat as needed. I was over at a neighbors while he was pulling a very large cylinder apart. He has an 18" wide flange I-beam for a hydraulic table and that thing looked like a pretzel while popping the nut from the stick cylinder on a 330 hoe. A little heat wouldn't hurt either. Good luck.
Bigger wrench and a 12' snipe. No idea what the torch spec. would be on that nut but the bolt holding the piston on my boom cylinder calls for 1,200 lbs. torch and black lock tight. I just keep getting longer snipes until the nuts let go.
Make a wrench from 1" plate with a 16" tail and beat on it with a 20 pound sledge. Most 1" impact wrenches cant touch that. I've been using that tool for 25 years on up to 4.25" nuts on some big scraper hoist cylinders.
same as RZucker
What force is that nut resisting that it's torqued to 1100 pounds? Lacking a dedicated vise, how do you hold that whole part? Never gotten into tearing down cylinders, so it's all new.
Yair . . . El Hombre One way is to slip the eye end into the drawbar of a dozer or somesuch. Use a suitable sized pin with spacers . . . support the nut end on timber baulks or blocks. Cheers.
What I do if I can, is pin the rod eye back to the machine and support the shiny bits on timber blocks.
I went down this road last year. I ended up taking my cylinders to a local heavy equipment repair shop. He had made a table out of a 2' tall I beam after seeing how it all went I knew I had no business trying to do it myself. I had the knowledge , not the correct tools.
As others have pointed out, either plasma cut a hexagon wrench from a piece of 1" plate, secure the rod eye to the machine towbar, support the shiny bits with hardwood blocks and whale away at it in complete confidence with the biggest FBH you have. the shock of the hammer blow usually works to loosen nut more easily than applying a steady but high load to it. Alternatively you can put a 1" square drive bar on the socket coupled with the biggest length of pipe you have and have a large person jump up and down on it....... 1,100ft lb is actually quite low. Some of our Hitachi cylinders the nut was torqued to about 9,000ft lb. We would use a 30-ton excavator to apply the pressure to the wrench. Edit: Found a photo of a home-made cylinder nut wrench........ View attachment 155144 A tip to get the correct torque when re-tightening if you don't have a torque wrench that goes that high is to mark the position of the nut with respect to the rod and so long as you are using all the same hard parts (rod, piston, & nut) when reassembling you can simply tighten the nut until the marks line up. Ratchets are not the tool for removing a piston nut IMHO.
Thanks for all the tips, I took the gland down to the local hydraulic shop. Best $20 I ever spent
:drinkup
Nige when I click on the link all I get is "Invalid Attachment specified. If you followed a valid link, please notify the administrator"
That happened to me too, and I have no idea why. The photo was there when I first uploaded the post. Let me see if I can repost it ..... Now I can see that fine. Let's see if it stays there.
I see it now, Nige. Thank you.
Nige, The link does not work. Bob
D@MN! 9,000 foot pounds of force? WOW! That is a lot of force. What are they using to twist the wrench in post # 19?
It's not shown in the photo but it was the bucket of a 30-ton excavator
Pinned rod into the back of another tractor, blocked up until level, 3/4 socket and breaker bar, 4' steel cheater pipe, one guy holding the socket on the bolt head, second guy standing (slight bouncing) on the pipe, and third guy pressing down like hell.
I was resealing some cylinders on the hoe part of my 416C , all three and one swing. Had already done the other swing. I thought I would take then apart and reseal them no problem. Problem. If you have seen the tables they put them on to disassemble them it pretty big deal. Torque multipliers , things changed down , 100 ton port a power pushing on special cut wrenches. After seeing it I have chose to stick to the lubrication department. Oil and grease no problem. The guy I used did a dipper cylinder on a 300 size Deere. He said it was about what Nige said , 11,000 ft lbs of torque. I don't see how it gets that tight, but I know I can't undo it.
Interesting thread; When I was sealing down all the cylinders on our first CASE 580SK, it was the dipper which took a little more "equipment" to remove / refit: Has been excellent since!
When I started wrenching, all I had was a 24" adjustable wrench and a chain wrench. And a 6' pipe. Rebuilt many a cylinder this way.
....or a zip wheel parallel to the flat of the nut.
heat heat heat / but lock tight and nylon ..overkill? wait if you heat nylon will it melt? make it worse ? weld a socket to a bar then to 1 1/2 cheaters? point it up and hook it to the pickup truck with chain :notworthy