Hello guy, I'm new to this site. I am new to posting on the internet to solve problems. I hope some of the experience on this site will be able to help me out. I am working on and 1998 cat IT14G tool carrier with a serial number 1wn00927. there appears to be some cracks appearing around the welded bushings that pin the steering cylinders to the machine. I am planning on grinding out the cracks and re-welding, but before I do I was hoping some one could tell me if this is a common problem on these machines due to the size of the plate metal, or am should I be looking for something that is causing the cracks like a sloppy pin/bushing in the articulation joint? any info would be a great help, I have some pictures I will try and figure out how to post them soon. Thanks
A few thoughts off the top of my head. Hitch bearing play and/or wear. Steering system pressure not within spec. Badly adjusted steering (frame) stops.
Lack of grease on the pins?
Post some photos. Let's see where the cracks are. Posting photos. Provided you are working on a PC or laptop.... 1. Open the photo you want to upload. 2. Open the Windows snipping tool. 3. Using the snipping tool select all or part of the area of the photo. 4. Paste the snip to the post where you want to upload the photo. Simples........
Here are some pics of the cracks
There was some welding done on it before but I don't believe the crack was groved out and it was just layed ontop of the crack. Now it looks like it's continuing past the old weld.
Do you have any photos taken from a bit further away to give it a bit of perspective.?
I don't have any, I was going to take a few but my phone died. I will try and get some tomorrow.
Here are some pictures one from a bit further away I removed the steering cylinder and cleaned it up a bit
Excellent photos, and the first one raises a question. Is there any evidence of a rubber or hard plastic face to the steering frame stop mount (the one with the threaded hole in the centre) seen in the upper part of the picture.? What about the other side of the machine.? I'm guessing the answer will be no. If that's the case there's the reason why you have cracks in the frame. The steering has been banging the front and rear frames hard against each other when the machine is at full turn angle. Are the cracks limited to the upper bracket where the steering cylinder pin fits, or do you have cracks in the lower bracket also.?
They are odd cracks that don't appear to be caused by normal steering action. Slamming the steering metal to metal seems likely. If it was a problem with the pins I think there would be cracking along the edge of the welds. Is it possible the steering hyd. pressure is too high? I don't know if loaders slow the speed when nearing the end of travel like the swing on backhoes do. If not having having some kind of rubber/plastic stop to cushion the blow would make sense.
From the Parts Manual. Those pads are at least 2" thick including the backing IIRC. IMHO the impacts caused by the forces on the steering cylinders and the frames hitting metal-to-metal are what has caused the cracking. YMMV. No loader has any sort of pressure/speed control on the steering system during the cylinder stroke other than how fast the operator turns the wheel or how hard he holds the joystick over. Larger machines have a hydraulic neutralizer to cut the steering hydraulics before the frame stops hit each other. Extremely baaaaad things happen on big machines if the two frame stops hit one another.
There is a rubber mount in that location on the opposite side of the machine. It has seen "better days" though. Should there be two on this machine? Does anyone know where on the internet I could obtain a copy of the parts manual and a service manual? I uploaded a picture of the mount on the other side also
Both the upper and lower bushings that the pin goes through are cracked.
That's it, and yes there should be one of those on both sides. If there is no cracking in the steering cylinder mounts on the left side then you have found the reason for the cracks on the right side mount. To completely replace both the stops you will need the following parts: - 2 x 112-0885 Pad As - Resilient 2 x 129-8087 Spacer 2 x 7X-7729 Hard Washer 2 x 8T-4196 Bolt
Have a look on the usual internet sites for the following: - Parts Manual - SEBP3126 (New Price $155 in paper form, $110 on CD) Service Manual - SENR6760 (New Price $865 in paper form, $465 on CD) Be aware that internet sellers can be very proud of their used manuals, so much so that they ask higher than new prices for them - like this Part Manual. It's only $155 new for the latest version (v56) and yet they are asking $200 for one (v11) that's almost 20 years old...!! https://www.ebay.com/itm/CAT-CATERP...ARRIER-PARTS-MANUAL-SEBP3126-11-/223899712910 This Service Manual, on the other hand, could be a better deal - https://www.ebay.com/p/8026180773?iid=321211428635 When buying used paper Service Manuals online, the key question to ask the seller is "Is it complete?" If they don't know, ask them to list all the separate sections that the manual they have for sale contains, then post them up here. It's easy enough to check if anything is missing or not.
I suggest that you pull the RH steering cylinder apart and check the condition of the piston & the bottom of the cylinder barrel. With that pad MIA it’s likely that the “stop” when steering the machine full to the right has been the piston in the RH steering cylinder hitting the bottom of the barrel.
This is the bottom of the steering mount on the side that still has a little rubber left on it. It has a crack that looks like it's following the weld around the bushing. Not sure what the top looks like yet as the pin is covering it. Do you think the stops could still be the culprit?
The cracks on the left that has the remnants of a stop are nowhere near the extent of those on the right which does not. My vote would be the lack of stops in good condition being the root cause of the cracks. To confirm, why not pull both steering cylinders apart and look down the hole. Compare what you see between the RH & LH sides. Take photos.
Thanks you very much! This has been way more helpful than I ever imagined it would be. I will take photos and post them when I get it. Thanks again
Last pic. is too close up. Looks like a seriously wallowed out hole though. If the two frames were slamming metal to metal could cause all kinds of seemingly odd cracking. I recall reading of some cylinders that have cushions inside so they don't slam hard at the end of stroke. Not sure if they were steering cylinders or used for something else. I think the cracks can be repaired but might require some way to make sure the cracks are completely ground the full depth of the cracks. With air arcing/gouging you can usually see but if not something like Dye Penetrant would be easy to use or mag particle testing if you have the equipment. Just using a grinder often makes it very difficult to see if the crack(s) are completely ground out.
Seconded on the dye penetrant. One of the few ways to see whether or not a crack has been completely eliminated. When you get to grinding the cracks out, start with just one and post pics after grinding. I'm sure we can come up with some suggestions of things you may not have thought of that might help to make a long-lasting repair.
I'm no expert welder, But my plan was to grind a little more than half way through the plate and weld that. Then grind on the opposite side into the weld hopefully completely eliminateing the crack. I will take some pictures tomorrow of my grinding work.
Unless you are skilled in welding overhead (or you plan to turn the machine upside down to weld underneath the brackets) I would suggest that you grind right through from top to bottom, using a narrow cutoff wheel when you get right into the root, leaving something like a 3mm gap between the plates. You could then tack a piece of flat bar underneath and weld from the root (where perfect fusion is most critical) right to the top surface. Once you have that weld completed it would be a case of grinding the flat bar off, doing a bit of grind prep where the flat bar was, then complete everything with a single pass working overhead to "seal" the bottom. The drawing below is a crude ateempt to illustrate what I mean. Always grind all welds smooth to the same profile as the parent plate when you've finished them. If you have a needle-peeding gun, or can borrow one, that's a great way of stress-relieving welds. Hammer the bejasus out of the weld the the needle gun after every pass. TBH what worries me are those cracks emanating from the weld between the plate and the pin boss. I can't see a good way of making sure the crack is 100% ground out. I'm not sure whether it wouldn't be better to remove the bosses completely by air-arc or grinding the welds off, then repair the cracks, and finally weld the pin bosses back in place again. To do that would mean that you would most likely run into pin boss alignment issues though.
Those cracks are usually caused when the vertical pin joints of the hitch are sloppy and impact loading. Every time you put the bucket on the ground the weight is relieved and when you dig or pick up the bucket with a load in it, the joints will slap into the pins and what is left of the bushings. The machine frame needs to be separated, the cracks air arced out and welded, the hitch bores welded up and then both sets of frame bosses line bored to original dimensions. That normally isn't a job for anyone new to the trade.
Good point John. What with finding the steering stops buggered it took attention away from the hitch that did get a mention back in post #3 on Page 1. To the OP. Do you have, or can you get hold of, a magnetic-base dial indicator.?
Nearly all of those machines that I've done appraisals on had that problem. It's easy to tell, just push the bucket into the ground a little and then pick it up. You will see the front of the machine lurch forward.
A big advantage to using dye penetrant is that the crack may not be all the way through to the bottom of the plate. It would make the repair a lot easier if you didn't have to weld overhead or grind a backing plate off. If the bushings are still tight for the pins, I think the cracks could still be welded successfully although not that easy to prep. I think a die grinder could be used to widen the plate where the bushings fit enough to get a welding rod in there. It wouldn't hurt if the plate had some internal weld on the pin bushings. Preheat would be highly recommended. When the top swing swing mount ripped off my backhoe because a crack started at a grease fitting, I cut a Vee out of the 1" plate at the grease fitting and used 3/32" 7018 to fill the Vee going vertical up. The bushing was still attached to the ripped off plate so it worked like a backing plate. I built it up a little extra and carefully ground it so the repair isn't noticeable. I used a smaller thread size grease fitting and put it an angle from outside the welded section. So far it has held up great.
Yes I do have a dial indicator with mag base.
Good news. See the attached. I know it's for bigger machines than your IT14 but the measuring procedure is identical. See the last 3 or 4 pages of the document. I suggest that you measure the horizontal & vertical movement on both upper and lower articulation htches and post the results back here.
And while you’re making those measurements keep an eye on anything else that is moving that shouldn’t be and that you can’t fix with ty-wraps or duct tape.
There are things you can't fix with Ny-ties and duct tape? Say it ain't so!
It ain't so.
There are my welds I thought I did a better job taking picture of the grinding work but there are very few on my phone I guess I got caught up in my work
I found a couple of the grinding photos
Did you use dye penetrant as recommended by Dave to ensure you had eliminated all the crack.? How much further did you go down where the red line is.? Because it looks as though the crack goes further than it was ground in the photo. Also it looks deeper that what it is ground in the photo. Not trying to criticize or nit-pick, just commenting on what I see in the photos. In this one it looks suspiciously like there is still some evidence present of cracking in the area where the arrows are, plus the gouges in the fillet weld on the RH side are a bit ugly. They could easily start off another crack if left like they are.
As Nige says, no criticism just observations but it seems to me that picture Nige enlarged shows a weld bead that looks very porous, and must have been run really cold as the paint right up to the edge of the bead hasn't even turned color. Any paint or oil/grease traces left nearby will contaminate the weld and cause porosity bubbles. Goto filler metal in my world is 7018 stick at least, something like this I would run Eutectic 680 modified stainless or a less expensive alternate, 3/32" in the bottom, 1/8" cover probably. YMMV Oh, btw if you grind all the paint back a ways all around then heat things up with a torch following the cracks, then let it cool you will usually see the cracks taking off from where you thought they ended and showing up clearly. Some guys like to drill stop the end of the crack with about a 1/16" bit, old school then grind or gouge to vee it down.
Nige, Having you around is better than a well appointed Caterpillar technical library and a team of Technical Communicators available 24x7 & holidays, working for free.
Thanks for all the helpful advice, I know I am not a seasoned welder mechanic and have much to learn. I did grind a lot more away from both of those pictures. I didn't use any dye. I didn't have access to any and just went with my eye and ground as much as I could until I figured I had it all ground out. I wasn't aware that heating up after grinding would expose the cracks, I will try that out next time. But it did seem like the metal filings were sticking to the crack almost like magnetized. I wasn't aware that the grinding marks would be an issue, can I just dress them out with a sanding disk?
Any hickey left after welding or grinding can create a stress riser which potentially could start another crack. Personally I’d recommend that you burn the paint off in that area and run a couple of passes of weld to (over)fill the grooves left by the grinding, then carefully grind the weld back to conform to the original profile as close as you can. Burning the paint off will get a bit of heat into the steel before you start welding and help to reduce stresses when everything cools. I hope you’re doing these repairs inside a heated shop.? Also if you haven’t done anything more to the repair in the 2nd photo I posted I’d strongly suggest that you revisit it and open it up a bit more because I’m almost certain that there is more crack there that has not been tackled unless the photo is playing tricks. In corners as tight as where you’re working a Dremel can often be a good idea for carefully opening up cracks.
No evidence of preheating at all, looks to be welded with short circuit Mig with weld craters left at the end of welds (much better to weld in from each end), no guarantee that cracks were completely ground out and actually shows evidence of cracks after grinding and incomplete fill. Looks to me like a case of being in too much of hurry to do it right. Any welding or industrial supply should have dye penetrant kits or individual cans of penetrant, developer and cleaner. Probably cost about $50 maybe less depending on brand. A little frustrating when it's explained how to do it right but the steps aren't followed.
Don't worry a lot about people looking at a low resolution photo over the internet are calling cracks and all kinds of gloom and doom. You do the best you can with what you have. You have an old and small machine that it appears from your posts is just a hobby machine. With the visible damage that can be confirmed in your photos, there really isn't much you can do short of cutting the whole weldment out and putting in a new one. The machine isn't worth that much time and effort. Run it and check it every so often and it will likely last far longer than the work you need to accomplish.
Wouldn't think a little preheat and dye penetrant is too much time and effort. Even a portable propane torch would add some preheat. The whole idea of doing a repair is to fix a problem before it becomes a much bigger problem. The cracks in question weren't a major repair if properly done. That's why the steps to take were posted. If the damage was more severe I think the consensus would have been to have someone more experienced do the repairs. Steering on a wheel loader is fairly important and an IT14G isn't an ancient relic. A finer grit flap disc is good for final clean up.
Outstanding reply . Bob
Ouch!!! Well I just hope that I didn't make it worse than it was when I started. Chalk this one up to learning on the welding and remember to were your welding shield when reading comments about your skill level!!
In my experience with repairs like that ,if your doing a full teardown on the machine you can get usually get in and do full penetration welds in spots like that. Otherwise with the machine still assembled you get in with an angle grinder or a rotary file on a die grinder and do the best you can . Air arc is great on bigger cracks. No matter what you need to preheat till your spit sizzles on it , primitive but it works. This will show 9 out of 10 cracks . Stay away from these repairs with mig/hard wire! 7018 or if you want to be fussy Arctec 223 is good . 3/32 or 1/8 usually does the trick in any position ,run it a little hotter . Ive done hundreds of these repairs successfully ,usually out in the bush in sh#tty conditions . If you can cure the problem,as noted above by putting the stop cushions in , a field repair like this generally lasts just fine.