Okay... First post - be gentle! I've recently purchased an old EX200-2. It is still fully functional, however the boom cylinder moves around 2cm before 'engaging', implying that the pin and/or bush are worn well beyond tolerance. I'm attempting to replace the bushes and pins on the boom cylinders (the pin that connects the boom to the frame). I've removed the retaining/stopper pin and managed to move the main pin around 1-inch using a pry bar. Beyond that point it appears to be stuck! I'm using a pry-bar with a 1m pipe on the end to move the pin and it moves nicely until it hits some sort of catch at the 1 inch point... I've had a second person slowly move the boom cylinder in and out while I'm hanging off the pin with no joy. The workshop manual was not-so-helpful, with the instructions summerised in a single step: "Remove rings, stopper pins and, pin"... There don't appear to be any special tools. Has anybody experienced this before? Advice? Regards, Red
Looks like there is a hole in the frame to get at the pin. Large punch and BFH. There is probably a wear groove catching. It might take a *gas ax* to get it out. Good luck.
you will also have to pry or come-a-long the cylinder towards the boom as they are at an angle and using the hydraulics to move them up and down is not enough to get the pin centered if there is considerable wear to make a ridge in there it will catch and make it seemingly unmovable.
Have an operator boom up and down very slightly while putting pressure on the pin. (I/E move the cylinder up and down.)
Shimmy1, I like your point about the hole in the frame (I checked and there is an equivalent hole on the other-side for the other cylinder - belly plate is now removed for access). The Hole is a long way off the pin 'center', and the amount of room to hold a punch and swing a BFH on the other-side is minimal (25-30 cm max). I've tried using a hydraulic jack (from the car) which looked like it might be Okay - unfortunately due tot he confined space, I couldn't get the leverage on the hand-pump. I'm also not sure that steel plate that the jack is pushing on won't bend... I will see if I can create a custom 'punch' so I have more room to swing a 14lb tack-hammer...
excavator - good idea, I already tried that
Another excellent point! I'll probably need to get 3 people though, one operator move the boom cylinder at the normal angle, one to move the boom cylinder joint straight up with a pry bar and a third person to push out on the pin with a pry bar... Hmmm - may need more prybars and pipe!
I had to do this on an old loader... little smaller and lighter but should work
G'day, Same problem but much smaller, bobcat Backhoe attachment. Not easy. However block and tackle assisted in holding the cylinder by lifting to overhead gantry - my excavator - working on my own and allowed moving in very small increments. Still fiddly to position correctly. Since that time I have purchased a Porta Power. That would put at least 5 ton of pressure on the pin with the right attachment even in a confined space. Hire or borrow one if you can. Don't put anything personal near the Porta Power as that is a lot of pressure if it slips ( it hurts )! I would have a pry bar underneath the assembly to lift as well as in and out and go slowly. Apply pressure at the same time as you move the cylinder. I think the suggestion that it has a worn bevel is probably right and catching particularly as an inch is about the space it would move until the non worn bit would hit the worn section which is not aligned. Patience is paramount. Good luck, MX45
the good thing about a porta power is the constant pressure so when you get it alined it will start moving with a hammer you hope to hit it when it's lined up
In the absence of a proper "Porta Power", I'm using a hydraulic car jack - I'm able to get it thorough the hole that Shimmy1 pointed out, and I have a 6 ft crowbar moving the base of the cylinder up and down. The pin has moved an additional 5mm (alot!), it is slow going but progress is occuring (I'm taking a short break during the latest rain squall)... I'll put a couple of photos up shortly...
Teaspoonful of C4 and a detonator should do...
G'day, Car jacks are designed to go up and down not sideways - you may run out of power or in fact have none when you think you have some pressure on? If you have a mechanical scissor jack you could be certain of some pressure or a Landcruiser winding jack? Be certain to support that heavy part you are disconnecting. I would not want to be underneath. Cheers, MX45
Dead right the car jack was soooo close! I managed to get some power but the angles are really painful (either I have power but no where to crank the handle or the other way around). I'm about to go hunting for a suitable porta power... I also have the cylinder supported with a nylon strop around it - I don't want to be in the way if it falls!
Most bottle jacks work fine as long as the pump is on the bottom side. There are a few that require a different angle to keep oil in the pump. You could weld a pad eye on the head of that pin and apply some pull to it with a chain hoist or even a ratchet binder, just a thought. When you get so far it will jump loose, until the other unworn end gets to the tight spot!
G'day, Wishing you luck and probably at the risk of being a redundant point. Buy once! Lots of Chinese around that could be good could be bad. I have had much more fortune with buying made in Taiwan than made in China. Get a push and pull in a kit if possible. Couple of hundred on ebay. Repco have some with warranty and a local store. I bought from a spe******t hydraulics company for 'quality'. Get a gauge in line so you know what pressure you have and for safety reasons. I am certain there are more experienced and spe******t individuals on here but if you have heavy equipment you might not have to reach for the porta power too often but when you do it is worth it. Regards, MX45.
and the last thing you want to have to work on cheap tools to work be able to work on whats broken
If you were to eliminate that lip on the right side of the pin you could push it thru ... and nip off what comes out the other side. problem with a porta ...it will fall off should you decide to clank the machine around. ... drive it operate the boom. A heavy duty bridge with a pusher bolt...the bolt ten to twenty percent smaller than the pin. push and clank around a little. ...repeat. ..nip off as needed.
Oh the push bolt 'bridge' would look like the letter "E" With the center of the E' your jack bolt. ...the rest the bridge.... The center of the bridge has a nut welded to
Welded to it. Weld the bridge on goodly. Kapeesh?
You could make a baby bridge first. ...sometimes it don't need alot it's the clanking around and re tightening the pusher that does it.
Damn! I wish I'd seen this post earlier!! I went to Gasweld and felt that $230 was a fair price to pay for a basic kit (no pull)... It broke within 10 mins...
It's a possibility, although I'm hoping to avoid that if I possibly can - cutting through an 80mm hardened pin in a relatively confined *once* would be an "experience"... Doing it 15-20 times would not be fun (the pin is around 25cm long and i only have 32mm clearance)... I am considering widening/adjusting the 'access' hole so that the entire pin could go through... I'd take the lip off as you suggested but no need to nip and repeat.
G'day, Unless you have X ray vision and are a metallurgist you don't know what you are getting from the box of chocolates at the store. I guess the wrapping looked good. I considered Gasweld, et al but experience taught me what everyone knows but gets tempted to flirt with - 'you get what you pay for'. They should refund I am sure - it failed. Blocking evenly at the foot is of course necessary to spread the pressure - bits of wood, etc. You could still try to use it if you can find footing under the actual cylinder. Glad no-one got hurt I presume. The problem could be the worn section is not evenly worn and has mis-shapen the pin so that it is not square with the hole no matter what. I can only imagine what I would do next. A good stubby drill with HSS bits and lots and lots of patience drilling some holes to relieve the pressure on the pin by drilling into it? If there is enough space for a bi-metal hacksaw blade (several of them) on a demolition reciprocating saw and cut between the cylinder end and the supporting frame piece? Lots of cooling for the cutting. Better minds than mine can probably shoot holes in that but best I can think of now you are breaking equipment. Cut both sides you could then pull the ram and work on a bench with a 20 ton press to get out what is left. Perhaps some old engineers could get on to this thread and give better advices. Good luck again. MX45
Just a further simple thought - have you tried to turn the pin at the accessible end a mm or two at a time and hammer from the other end/apply pressure? Reason being the worn section will align differently at each mm and one would hope give a little or a lot in a different position? Release pressure from the ram by loosening a feed line to ensure it is not being held too tightly from the hydraulics? Not open just bleeding, be sure to have the boom mechanically supported = not able to slip. Tap it back in a little prior to turning to disengage any catching. Mark the position you are in with a punch mark somewhere and then you will know if you are moving the pin at all.
What happened - any update? MX45
I've been away for the last few weeks - so the short answer is nothing! The next plan is to find a sufficiently large stilson ( grip of 100mm+) to turn the pin, as you suggested above.
As much as you have fought with it to get it out that far .I would knock it back in ,Which should free it up again , then turn the pin 90 degrees,as the wear lip that your fighting with should only be top and bottom of the pin. Worth a try ,What do others think ?
Or get a piercing torch in, blow through the center all the way and hog it out until there's only a centimeter of thickness left all around, should shrink up and practically fall out. May be the court of last resort, you're not going to reuse the pin anyway, yeah?
I finally got some time to work on this issue again - Stage 1 complete! I used an angle grinder with cutting disk to increase the hole that the hydraulic press was going through - in hindsight, it was too far off centre to get good pressure...). This was then combined with MX45s suggestion of rotating it with a big stilson (see pictures) Now one of the pins is now out, so I can now clearly see the groove wear pattern that was causing me so much trouble. It looks like a cam with 5mm worn in the center (where it rotated inside the boom cylinder bush) and around 2mm worn on the opposite side where it wasn't supposed to move at all! A big 'thankyou' to everyone who has offered advice up to this point (in particular MX45 for the pin rotation suggestion - that was gold!) I have a replacement bush all set and ready to go - but no pins... Most of the suppliers on Alibaba weren't clear on what I wanted. A friend who works in a workshop at a local University has offered to machine and harden something... We'll see how he goes! I'll drop a few more updates as I make more progress (I think the delays will mostly be my day-job getting in the way!)
G'day, I see the porta power still working at one end - marvelous things aren't they when you need an extra strong hand at the other end? I am glad you had joy in the end. Perseverance is gold as well. Congrats! Enjoy the machine. They are marvelous things when working the right way. BTW besides a very modern Porta Power in my kit which I have used more than for the original job I have a very big pair of old US made stilsons. Happy to have helped, MX45.
Wow. That pin looks like the only grease it ever saw was the grease from the factory. SMH.
Yeah, one thing that helps on excavators is to boom down a bit when greasing, opens up the space on both ends of the boom cylinders to allow grease to flow to the relatively narrow sector that gets all the load applied to it.
Weld a ring to the pin and use a ratchet type load binder to pull on it while you BFH the other side.