I work for a construction company in California. Nice fleet of mostly Cat equipment. The operator of the 14M said there is too much free play/movement in the circle. The pinion was totally hammered and the circle was bad enough to replace 4 segments of the teeth. This is one that I have repaired before but I put classic parts in as genuine cat parts were not available at the time. This is only after one season of use also so I hope these cat parts hold up better than the classics. Got the circle off the machine, level in the shop, and cleaned off.
With the cost involved in the repair, I would have a local scrap yard shoot the classic replacement pieces & and the CAT pieces with an XRF gun, and go from there.
That’s very interesting. Never heard of it, had to google it. That would be good to know the differences in the parts. Thanks. I repaired a 14H circle with genuine cat parts a couple years ago, they look great, very little wear. I was able to get genuine cat parts for this repair as well. I’ll be posting progress…
Great pics. Following the repair!!! Welcome to HEF!!!!
Unless it was for a hobby machine I would steer well clear of Classic Parts.
Do they use lube on the pinion? Operators here seem to think dry is better. Book says to use grease I think.
The recommendatoin is a 5% moly grease but personally I would say leave the pinion dry. Grease seems to mix with dirt and produce something akin to valve grinding compund, especailly with grader operators who like to use their machine as a dozer. We used aerosol dry flim lubricant on the top surface of the circle where it rotated on the drawbar and that was it.
Thank you 8V71. I shall pass that along. And agreed Nige. I am not a favorite of material going over top off the blade although sometimes inevitable.
We tried grease but too much dirt and small rocks stuck to it so we run it dry. That pinion guard is interesting though, makes me wonder how that would work in the long run? Would it pack full of dirt, and grease? I have never seen one of those installed on a machine.
Neither have I, and the fact that the guard is not totally sealed means dirt will get into the space around the pinion with what I would think would be the same result as greasing the pinion manually.
Found DNC (Dead Nuts Center) of the circle. View attachment IMG_4512.jpeg Measured around the circle, I measured 59 7/16’’ from tip to tip. I usually don’t like tape measures with the magnet tip on them but I used on for this and it worked out really good. Now I’ll stick with this tape for the whole job to try and get the most consistent measurements. Cat spec for this is .062 which is pretty forgiving I think. View attachment IMG_4514.jpeg The task at hand View attachment IMG_4515.jpeg
The first one the procedure tells you to install is the front middle segment. I scribed center lines on the line up template and the segment to try to be as accurate as possible. View attachment IMG_4517.jpeg Marked around the replacement segment. View attachment IMG_4519.jpeg View attachment IMG_4524.jpeg And cut! View attachment IMG_4528.jpeg
What is the Cat recommended welding procedure for the actual welding?
They reference a special instruction REHS1841 for “General welding procedures”. Which goes over different welding processes. A lot of good information in it. For welding the segments in it only says use low heat and a continuous .25’’ bevel groove weld. No more specifics, no actual pre/post heat temps or welding process.
There is also another one, SEBD0512 Service Welding Guide, but it is classed as a Reuse & Salvage Guideline so you need dealer access to SIS to find an electronic copy of it. Attached is a photo of the cover of my paper copy from way back when.
Our new CAT 150 has what CAT calls the "Circle Saver" option. It's the item outlined in Heavy's attachment. The Owner's Manual says to add grease every 10 hours. Although it doesn't explain how much. I am going to follow the OM's guidance. I pumped the cannister full of grease, almost two full cartridges. I add 5-10 pumps, move the circle, add 5-10 pumps every couple days of operation. A neighboring Township has the same machine. They've never added grease. 1200hrs on the clock. Their circle clunks and thumps along when turning, with an occasional squeak. Mine is smooth/quiet. Also "seems" like it is a bit more powerful although I can't quantify that. At the end of our upcoming dusty season I'll post my opinion about the value of doing this. Back to the topic of this thread. I'm very much enjoying the updates with pictures. Learning how a circle is professionally rebuilt here. Thanks for the progress reports!!!
Some preheating would be a good idea to help prevent cracking of the root passes. They likely want small 1/4” passes to keep the grain structure in the heat affected zone close to original
Are you using dry film lubricant on the sliding surface between the circle and the drawbar.? In my experience failure to do that can tear up the plastic thrust plates.
One place i worked at we used spray-on moly/graphite top and bottom of the circle and the shoes. Worked well and didn’t attract grit
Are you referring to the top horizontal surface? If so yes. But I'll adjust to whatever you suggest. If you are referring the the side vertical surface? I have not. Again I'll yield to your expertise.
Yessir. The easiest way I know of to do it is to raise the moldboard slightly off the ground which will create a small gap between the top surface of the circle and the bottom surface of the drawbar. The dry film lube is then sprayed into that gap all the way around the circle. In places where the drawbar doesn't cover the circle then the lube can be sprayed directly on to the top of the circle. I'm referring to the gap marked "A" in the drawing below, taken from the circle adjustment procedure.
Yep, that's how I do it. Would be a lot easier with a reliable operator to slowly turn the circle. Then I could use the holes in the top of the drawbar.
The cutting went ok but I was cutting through 2 welds with about a 1’’ air gap in between them in some spots so I had to crank up the oxygen pressure and go really slow. I’m going to try to stay more on the segment side on the next ones I cut out then grind the welds off of the circle. #2 tip with 7 psi on the acetylene and 100 psi on the oxygen. View attachment IMG_4533.jpeg These are the best grinding discs I’ve used. The orange Pearls are a close 2nd. I had to grind the curled up edge of the bottom of the circle teeth then installed a bottom plate I made. The gap needs to be between the circle and the plate to access the segment for tack welds. View attachment IMG_4535.jpeg Installed segment and measure, measure, check with alignment tool, measure. View attachment IMG_4536.jpeg
Very cool update Heavy!!! I like the bottom plate you fab'd!!!
Thank you. That’s a 3/8’’ plate with a radius cut in it to match the circle. I gave it a few coats of dry graphite spray. It helps to keep the weld spatter from sticking to it and keep it from rusting on the shelf.
Are the pictures coming up in the thread for you guys or do you have to click on links?
First segment in and tacked.
And onto the next View attachment IMG_4545.jpeg View attachment IMG_4555.jpeg View attachment IMG_4556.jpeg Before tacking these in I check the placement with the alignment tool, measure the distance across at 59 7/16’’ and check the height. And triple check everything before tacking.
That was a nice job. Just a shame that you had to do it iiwce because of poor quality parts.
Shouldn't need 100 PSI oxygen pressure for cutting that thickness. 60 would be plenty but cutting through the solid part of the segments would make it easier. A larger tip size might help. Once cut could go back and torch off the thin bit left. Gouging/cutting out the top weld and cutting short sections of the segments might let you pound on the cut pieces and break the bottom weld if it's only a 1/4" weld.
In the beginning I had to click on each one. But lately they are coming up in the thread. Either way is no big deal. I really appreciate you taking time to post.
You’re right, I can probably dial back the oxygen pressure. Just want to make sure I blow through both welds and not blow lava back in my face. On previous jobs I used a #3 but it seemed like the cut was better with a #2 and higher pressure. The cut with the #2 was more of a smooth cut as the cut with the #3 was more coarse, if that makes sense. May have just been me.
More progress. View attachment IMG_4557.jpeg View attachment IMG_4558.jpeg Just repeating the same process for each segment. Measure, measure, measure. View attachment IMG_4560.jpeg View attachment IMG_4561.jpeg I noticed that the top and bottom of the classic segments are machined, the genuine cat segments are not. Not that this matters at all just a difference I noticed.
You need to have a really clean tip where the cutting jet is straight about a foot long or longer when you press the lever. You did a good job though. In a perfect world the welds would be air arced off on both sides flipping the circle frame over to do both in flat position.
All segments tacked in. View attachment IMG_4565.jpeg Preheated the circle to 200. First pass welded on the top of the circle, then I flipped it over to weld the bottom. View attachment IMG_4568.jpeg View attachment IMG_4573.jpeg 3 passes on the bottom, ground flat, sanded smooth.
Flipped it back over and finished the top. 3 passes on the top, then filled in the big v grooves at the ends of the segments. View attachment IMG_4575.jpeg Ground flat and sanded smooth. View attachment IMG_4578.jpeg
Welded with .045 dual shield. I use Hobart Fabco triple 7 wire. View attachment IMG_4543.jpeg Volts set at 23.5, wire speed at 305.
I let it cool all the way down and measured it again. All the measurements looked good. Used a straight edge on the top wear surface to make sure none of the welds were too high.
Very nice!!!! Where the new pieces meet the old pieces, in the middle of a tooth, do you penetrate all the way to the center of the tooth and fill the seam with weld? Trying to imagine how to do that. Assuming the top weld and bottom weld along the circle don't completely fill the gap as evident when you cut off the old pieces?
Looks good. Would have been a pain to weld overhead. Could have been a little hotter or a little more volts to flatten the bead out but there's enough weld it won't matter strength wise. I don't think it matters if where the sections meet it's not 100% penetration. There's enough thickness in the teeth and the force is put on the sides of the teeth. If the teeth were more like a std. sprocket then you'd probably want full penetration.
Thank you. I cut straight down on the original circle tooth. There is a pretty large bevel on the top and bottom of the ends of the new segments. So I just filled up the top and bottom bevels with weld. And then for the tip of the tooth is basically just a butt weld, just welded up and sanded smooth. The illustration is looking straight at the tip of the tooth. And you can see the top view before I welded it. Hope that makes sense. Correct, the top and bottom welds are spaced out about an inch.
Got the machine put back together and it’s back to work. I’ll update at the end of the season. Fingers crossed these segments hold up better.
They should be good for a long time.