Slewing ring (rotec) bearing replacement

well tctractors, i don't quite understand why you don't think how using a hydraulic wrench wouldn't be a good way to go? my shoulders would be mush after loosening and tightening 60 bolts on this ring! i do understand that direct wreching would be faster not including the recovery time to get blood back in the arms, lol..at this point it is all null and void with the hydro wrench i went thru the effort of sending someone 5 hours drive today and the guy with the wrench is an obvious tweeker (to many drugs) and declined to take the check after saying it was ok yesterday now he only wants cash, that kind of crap wears me out faster than a 1" drive rachet. again thanks for the ideas and conversation i am here to learn from others and provide what i can...........theironoracle

tctractors, just went through all 27 pages of using a bit of hydraulic muscle and found no pics with bearing removal. help me again. and when is search "Slop in turntable" i don't find that heading anywhere..............theironoracle

never mind, got it!!! i will cut and paste it here: - slop in turntable, how much is too much? -.....theironoracle

Theoricale, the bolts on the ring are the part you have to graft at, some ring mounts are very restrictive and only a spanner or a short socket on a breaker bar with fit?? 60 or so bolts are soon undone and as you have a bit of help working with you its easy to use a chain on your wrench and swing the top with the engine to undo them all, just think about where to place the chain as it can save your back some, the bolts only take a few hours to remove on lots of excavators, you will need blanking plugs for the pipes going to the centre joint etc.

A 2800CII is a pretty small machine. You can break all the bolts loose easily with a 3/4" drive ratchet unless the last people put liquid lock washer on the threads. If that is the case I just heated the heads of the bolts some and then went right to turning them out. I have a 600 footpound torque wrench I've always used for bearing bolts. Also as I recall all the bolts on this machine can be accessed from outside the house. You don't have to pull the cab or fuel tank for bolts that come down from the house to threads in the bearing.

If you work hard and have a good helper it takes around 30 hours to do it efficiently and right. I usually wouldn't work with jacks and preferred to have another machine to pick on the counterweight while I used the boom to pick the front. If you have the plugs and caps as mentioned previously the job is a nervous piece of cake. It's only the threat of gravity that makes me nervous when doing these.

I have colleagues who do 4300 model loggers in less than twenty hours.

Good Luck

Replaced slew ring on a pc 300 12 months ago as follows, unbolted superstructure from top circle bolts, capped lower hoses at rotary joint, used a 20 tonne crane to lift superstructure, counterweight and boom all in one hit, started machine and lowered boom to ground as top was raised to keep level, unbolted lower circle bolts and lifted bearing out with tele handler hooked up short. cleaned out new bearing bolt holes and bolts for loctite, replaced bearing, fitted lower bolts, cleaned out slew grease bowl and refilled, lowered superstructure back down, aligned, fitted & torqued top bolts, refitted hoses.
All bolts done by hand, myself and customer did the job in a day. I have heard of blokes doing them with jacks and dunnage and not being comfortable, especially when everything starts to move. suppose it depends on the set up.

Wick, that was a long day I'm guessing but I'm sure you really went to town on it. How did you get the bolts under the cab?

the"O" and Wick, as I have already said we all do things our own way, its a shame the clip from the Slop in turntable thing does not click up, anyhow using a Crane to lift about a 30 ton swinger top bit would be very scarce to find in the U.K. the owners just would not pay the coins to Hire in the Iron, unless by some luck they had a Crane within their work equipment, I dont think I would bother to use 1 though, as I try to stick to what I can do by myself, I once did a bearing swap on a JCB 812 or 814 that took from 7.30 am till 12.30 on a Saterday morning to sort, but I had the help of another real hard grafter mechanic to help me plus we were covered in crap off the dirty pig of a thing, it often seems to me that the mechanics in the USA get some good stuff, take their work trucks, if I turned up at sites with a truck with cranes, compressor kit etc all loaded onto a long hood Mack, I would not get past the gate due to some site policy etc, plus anything to save the Man is not thought well of, the U.K. sites often dont give any consideration to repair work and dont like it being done within the site location, I was called out to a running fault on an Excavator a few years back, the machine was just a few months old, I found the fuel tank to be empty, the Site Agent said that the machine was crap as its broken down and he wanted it off the site, I pointed out to him they need fuel to run and he was going to be charged for my call out, this was the man in charge of the Site and he realy struggled to understand that the Excavator needed fuel to run, if he changed it for another 1 it still needed the fuel tank filling, I sometimes meet some amazing people, how do they get these fancy jobs.

i got the torque spec for this slew ring i am going to do but no procedure. do i just put them in and torque them in order? or should i worry about a cross torque pattern? any thoughts?......theironoracle

G'day John, the machine we did is a logging machine with a processor head and a raised cab there is a cavity below the cab (about a foot high) to access the top ring bolts in that section of the circle, you just can't get much of a swing with the socket, bar and pipe.

theironoracle,
We usually just torqued the bolts down following the circle. Never had a problem with it.

Wick
I did a similar machine a bunch of years ago. It had an eighteen inch riser. It also had two Allied winches in the way as it was a yoder. Logging shovels with a tilt cab are a piece of cake. Excavators though are a real pain as I've had to pull the cab shell and floor plate.

so when does this project get underway?

the customer is finishing a project up with the machine then it is mine between jobs. its not working real hard but has to be available. he will probably need it done as soon as my schedule gets overwhelming, oh well there are worse problems to have than too much work......theironoracle

Bear with me as I may asking a stupid question, but why is is a waste of time to pull the trucks from under the house? We are in the middle of changing the same bearing on a 375L. We bought the machine knowing this was bad, seems the bolts came out of a rotation motor or two and really beat up the teeth on the inner race, more than 50% missing. Bearing still good. Found a good take out pretty cheap. But short of lifting the house 50 foot in air, I don't see a good way of getting a sling rigged over the top to lift and replace. Like many others, good tidy cribbing under back of house, and solid blocking under stick. Used power team rams and air over hydraulic pumps to push them. Brought stick all the way in to eliminate hydraulic creep there, lifted about three feet from ground and chained lift cylinders from extending any further. Bucket removed, used bucket pin with jack on both sides, and jacks on most outer pionts on back to have best control on lean. Jack and add cribbing. Jack and add cribbing. Pretty simple. Replaced rotation motors after bearing was out, as we were waiting on our bearing. Just can't see another way besides pulling undercarriage out from under house. We also use a hydro torque wrench, it's capable of 3300 ft.lbs. Impact tight, use the hydro wrench for final trque. Took us half a day to remove, a whole day to re install. Two poeple, sometimes three as the old man shows up from time to time to offer a hand. Not in a big hurry just steady and safe. Got pics too. But some explain why it's a waste of time to get the uc from under the house.

that's the way I done it coondog, im thinking (& iv been wrong before) that a lot of these guys are workin on small equipment not things the size of a 375bL. where they can get it that far up in the air to work on it or to man handle the ring out. its a different ballgame on the big equipment.
I feel better working on it out from under all that metal over my head also

I have done some fair sized ring swaps and as I have already said, we all do things in our own way, but I would not drive out Nowt just for the fun, coondog if you have swing box problems/damage then I would have left them in untill all the bolts were cracked and the hard to get ones were removed, then with a Big Bucket still hitched and the excavator in the up-lift position, I would pull out the swing box/s as this saves a large amount of jacking up, I have a great set of Enerpac style cylinders with an electrical powered pump set but I always use screw valved jacks, as for getting the ring out and in, well thats the simple bit?? whats the big deal, in the U.K. we would not be allowed to fuss about like you, the Boss's want it done and back to work without all the fancy bits, like I said "We all do things our own way, best of luck with your endeavours.
tctractors

Tc, I am sorry your bosses are not as endearing to you as the ones we evidently have here, this happens to be an era of caring about every bodies feelings here in the US and it seems that half of us don't FEEL like working. Having said that, I don't believe completing a ring swap on a 100 ton excavator with less than 24 labor hours can be categorized as fussing about. Including swapping both rotation motors, all in the field. I'll go up against any superior UK nonfussing boss fearing mechanics on this job. This was my first one, I already own the tools, have good hands and employees. Pulling the swing boxes doesn't help on this particular machine, I had no hard to get bolts. I am not complaining a bit about the job, I was only asking a simple question: why is it a waste of time to tug the undercarriage out from under the house? I understand now that UK mechanics are the best in the world, but you failed to answer the only QUESTION I asked. Try again.

We,ve changed a bunch of bearings and the easiest one ever was a 790 JD. We took some empty oil drums and put a 2" pipe through them about a foot down from the top, then filled them w concrete. These are the handiest blocking stands we ever had, with a forklift you just straddle the barrel w the forks and pick them up with the pipe.
We took all of the hoses off the rotary manifold and plugged them so that we could run the excavator. We removed the drive axles from the final drives. Turn the upper 90 degrees to the undercarriage. Take out all of the rotek bolts but 4 or 6. Stick the boom out to full extension so that the counterweight starts to lift. At this point put the loaded barrels under the counterweight and block them as tight as you can under it. Lower and bring the boom closer so that there is no strain on the bolts and the boom is in its sweet spot for lifting. Remove the remaining bolts. Carefully lower the boom so as to raise the upper enough so the swing pinion just clears the bearing.
With another machine pull the undercarriage out from under the upper. To clean the underside surface and remove broken bolts let the machine down on 2 more of the drums. Now you can freely service the bearing,grease tray etc.
To put it back together repeat the process,and when its time to line up the bolts use the swing function to find the first bolt hole then swing a little more to line up the next ones.
Just be cautious when lifting w the boom there is the possibility to knock the machine off the barrels.
No jacking, no cranes, took about 4 hours.

Coondog, the swing box pinions have to be lower than the the top plate to act into the tooth gear on the bearing??? so by stripping out the swing box's you would save having to jack up the top works by at least 150mm if not more??? the swing bearing I leave bolted to the top plate by a few bolts to take up the bearing clear of the grease path, then I place timber under the bearing and unbolt the few bolts keeping it attached to the top plate allowing it to sit on the timber ready to slide out, no big Drama just useing a bit of brains I think??? the ring will pull out very simply, this will allow you to pack timber off the Carbody to the underside of the top plate while you sort out the grease path and bearing location, I would have done more than 20 ring swaps mosty by myself or with the driver as a hand, I will admit that the largest ring I have swapped was on an old 245 CAT and the Quarry fitter gave me a hand.
To answer your question its simple, the jacks lift up the ring gear off the carbody untill the underside of the bearing is clear of the grease path then you pack under the bearing with timber, then by removing the few bolts that hold the bearing to the top plate the bearing easily slides towards the dipper arm/bucket, so now I have answered your question twice and I still have not driven the carbody an inch, I am glad you have all the gear??? I have little compaired but I would still manage to swap out a ring roller with a few bits of stick and a few slings, next time you tackle 1 of these jobs take a few moments to think how you would tackle it with minimal kit, I gave a pal of mine a hand to swap out a Komatsu ring once on a site, we lifted the counter weight off with a fairly big excavator that was not being used then undid the bolts and used the machine hydraulics and the biggish excavator to lift the top clear, it was O.K. but things get off line easy.

tctractors

Logs, we considered this method a bit before we went the way we did. We did not ave all of the plugs on hand, could have made them but still would've taken time. Also the way the hydraulic swivel is put in it would leave little room to plug of holes. And the inside of the belly is deep, would've taken us some time to get in there to plug them off on top. But we really considered it. We also have a 988h with a set of forks. Thought about using it to raise the back end, but voted against it. I saw a YouTube video on a much smaller machine done that way.

Tc, you are correct, the swing box pinions are much lower than the bottom plate, about 10 inches. However the hydraulic swivel is even lower. We ended up swapping both swing boxes anyways, because the teeth on them were as bad as the teeth on the inner race. Uninstalling the hydraulic swivel on this particular model would have taken more time than just jacking it up. I understand now about how you get it out though, you did a better job of answering. I do feel that would ave been a bit unsafe on a bearing of this size, but I coulda reached in and snagged it with that 88 with forks. I still would have had I jacked up about the same height as the bots were about 10 inches lng also. Some more of the story is I don't have a boss ramming me about getting it done because I own the quarry and equipment. One reason I have the tooling I do is to keep my guys safe and out of harms way. Anyhow thanks for answering the question, cleared up some confusion. Still don't agree necessarily, but I can se where it would hae been easier to line back up, although we did not have much of an issue here either.