For the experience cat undercarriage guys... I am seeing extra wear on the right outside rail side. That is to say the rail if bright polished on the side you can see. You can see metal has been removed. Tractor has 8000 hours on the rollers, idlers etc. Rails, segments, pads were new at 6500 hrs. System one series 2 (its not an alligator link, but it has a link that expands when you loosen the pad bolts, so you can field disassemble the chains) Soil conditions powder dry clay. I finished a long pull high draft, and stopped to check for heat. The outside roller flanges were warm to the touch, warmer as i moved toward the rear of the tractor. The rearmost roller flange was the warmest. Inside flanges cool. Left side rollers and rails cool. I tracked forward (low draft, high speed)to the other end of the field in 2nd gear and checked again. The situation was the same but the temps were higher. So after all that, what would cause the machine to polish one side of one rail. The other rail sides are not polished bright. Thx
That's NOT me. Did you check the alignment though? toe in, caster, camber? One of those doesn't apply, but it's too late to remember which is which...
A couple of things to check; Idler bearing wear. Cannon guide wear. Equaliser bar bearing wear.
Agreed. Something's not straight somewhere on the RH side, just a question of finding it.
Next time I'm on site I will check the idler bearings, hard bar flex points, and the main pivot shaft for signs of slop or movement. I suppose if I hoist the machine off the ground with the blade and ripper, I can use a small ex to poke and prod the heavy parts for signs of looseness.
Yair . . . . watglen Yeh, that or you could use a crowbar. (grins) Cheers.
Our D5G, smaller I know and not elevated, had strange wear like that too. Front idlers were running crooked, mainly due to the mount being wore so bad they would rock to one side 3/4"-1". Track frame was ok, rollers ok, segments ok. Rails measured ok externally but they had a lot of internal wear and we could push the track from the side towards the machine and see considerable movement. The combination of the two would allow the machine to spit a track on a slope and also was chewing up one side of the rail and front idle similar to what you're describing. Junkyard
To check the idler and cannon guides, lift the front, put a block of timber under the edge of a track pad and let it down to preload the undercarriage. Make a note of where everything is, lift the machine again and then put the timber under the other edge and watch for movement. To check the equaliser bar, measure the distance between the edge of a track pad and the machine frame near the front. Steer the machine hard and see if the distance changes. Also look for movement as you lift the front up and down with the blade.
To check the hard bar just push down the blade and lift the front of the machine while watching the end of the bar. If the bearing is bad the bar will move before the track frame does.
Im not following you here Cmark. Can you elaborate? "under the edge of a track pad to preload the undercarriage"?
The "cannon" is the large chrome cylinder that slides in and out of the rear track frame. It is kept from rotating by two guides. Wear can occur in theses guides and also in the slots in the cannon that the guides engage with. If you put a block under the outside edge of a track pad near the front idler and let the weight of the machine bear down on it, it will rotate the cannon to its furthest point, either CW or CCW. Make a note of where the cannon is in relation to the rear frame, put a sharpie mark on there or something. Then lift the machine and move the block to the other edge of the track pad. This will rotate the cannon as far as it will go in the other direction and tell you how much wear is in the guides. You can use the same technique to see how much play is in the front idler bearing.
I've got the dozer in the shop now. Visual inspection shows the bottom rollers wearing the outer flanges quite a bit more than the inner flanges. Chains want to run to the outside of the dozer on both idlers, and the sprocket. The carrier roller is also worn heavily to the outside. The problem is with the right track. The left track shows a little of the same, but not nearly as bad. Not finding any movement at the hardbar pivots. The pivot shaft seal is dry. There is some in/out movement on the pivot shaft (1/4"), both sides are the same. Roller bearings are all tight. This is system one machine. Clock hours around 8500, with new segments, chains, pads, and idler bearings at 6500 hrs. I will lift the machine off the ground and lower it onto blocks to check for idler bearing movement, cannon movement. There hasn't been much stretch so far on the chains, so there isn't much barrel chrome exposed. Chrome is dry. I figure I can use a string to check some simple alignments. I can use blocks to check for movement at the pivot shaft. I am thinking about the pivot shaft bushings here. I might pull the cover off the end of the pivot shaft to look for movement on the inside. I also wonder how much of this might be caused by previous roller wear. They put new chains on old rollers. Maybe the rollers were worn to one side for some reason to start with, and the new chains are running in the old path. Next post I'll have some more info
Here are some pics. Working on posting descriptions with them
More pics. Wish I could insert them inline
OK, here we go. Did a thorough examination. Started by lifting machine and setting it on one side, then the other, under the rear idler. Slight movement but nothing extreme. Same procedure under the pivot pin. No movement noted. Same under front idler. No movement in idler bearing, or cannon. I was hoping to see some rotation of the cannon, but nothing there either. I thought there should be at least a tiny bit. I marked it with marker. It is rock solid. Note that I used a block big enough so that the track pad was entirely suspended perched on the block. The free end of the pad was dangling, with the blade lifted. If that cannon was going to rotate, it would have rotated. Under the machine, I checked for movement in the 3 equalizer bar pins. Slight movement in one. Performed the same inspections on the good side of the tractor. Identical results found. Ran the tracks forward and back, slow and fast. Two of us spent a good amount of time climbing in, under, and around, the track frame. Off the ground, the only thing contacting the chain is the idlers, sprocket, and carrier. Chain hugs all these to the outside. Inside flanges on the bottom rollers are heavily corroded. They haven't been touched in a while. Meanwhile, the outer flanges are worn to the point they are disappearing. Carrier roller is wearing heavily to the outside. Scoured the track frame for cracked welds etc. None found. Visually Inspected for bent track frame. Looks fine. Pulled the cover off the pivot shaft, removed seal plug. Initially it appeared the pivot shaft was not centered in the hole, but cycling the tractor up and down showed no movement at all. I measured between the track pad and tractor frame at front and rear of tractor. 1/16" difference. I haven't tried a string line on anything. How do you check the idler alignment? How do you change it?
my vote is on worn rollers. Try removing the carrier roller then run the tracks With the machine suspended and see what happens. I know around here the do alot of plowing right down the edge of the road in the bar ditch which is hell on UC as far as twisting the rails goes and making them want to ride to one side. Maybe thats what started the wear on the old rollers and its just tranfering it to the new rails. just my 2
Hello again, I went back out and checked the toe. It's exactly the same distance front to rear. Some of the reading I did this aft had me wondering about the track tension. Checked it, it was pretty pretty tight. I may have been running it too tight for a long time. Slackened that off to spec. With the grouse cleats on there its tough to say whether the specs and measurements apply the same way, but I set it at 1.8" anyway. I think it runs a little quieter now.
I seem to remember there should be some alignment shims between the pivot shaft and the end cab to line things up with the sprocket teeth. I don't know on System 1 machines if that is true. When I used to do undercarriages I would string line the center of the sprocket teeth all the way down to the center of the front idler. I would line up the cent of the carrier roller on the string and would know I was close enough to not have problems on the top end. I haven't done high drives so I'm not sure of how to align the sprocket teeth to the rear idler for a check. I suppose you could use a straight edge off the sides of the teeth and run it down to the sides of the rear idler. On smaller machines, D3 Cat and Deere 450 I've seen bent track frames. I've not heard of a D6N or M ever doing that but I suppose it might not be impossible to happen. I've also seen plenty of machines working side hills do what you are showing.
I gathered up some straight edges and string tonight. Will have another go tomorrow morning. I checked the parts manual and it doesn't show any shims or spacers, which is weird in my mind.
I'm no expert by no means but have been thinking about this ( which is dangerous ). Anyway , I would think the sprocket drive or drive hub with segments would set a beginning point for the alignment of the roller frame. I wonder if you took a small jack and put some pressure on the e q bar , check that , then put some pressure on the pivot shaft to see if it moves outwards at all. I'm not talking about a lot of pressure just enough to see if it moves easily. The only other explanation , is the wear on that side , is the tractor running on a slope to ride on that side , does the operator favor a certain side to push with? Is the operator right or left handed? I am right handed and wear the right hand end bits more which would push the tractor to the left I think. Just thinking out loud here.
Thanks for your thoughts Dick, We spent all day poking and prodding with the skid steer. Between using the tractor blade and plow to lift and the skid steer, we've hit every part that could move. Today I'm going to get busy with the string lines and straight edges. I will measure the bottom rollers and rails to get a sense of the uneven wear. I'm thinking out loud here too.
I know it means quite a bit of work (but what's that work worth compared to the price of undercarriage parts..?) but thinking out loud would it make sense to split the tracks and raise the machine up on blocks/stands so that string lines could be strung (so to speak) from the rear idler to the front both over the top of the sprocket and underneath along the line of the track rollers as well..? I get the feeling that only if a line could be established without the tracks being in the way are you going to see a true picture of alignment.
We r doing that right now
String between idlers under rollers so that string was only touching idler rims. All rollers measure the same +- 1/32"
I should have added, the rollers are off center of the idlers by 1/4"
Carrier roller is centered on front idler and speocket
We took another hard look at the equalizer bar joints. There might be 1/16" play in there . Its so small you can barely say its there at all, even with gauge marks. Come along to pull tracks toward tractor. Wanted to get the tracks centered on idlers. Running the tracks in the air, the chains quickly move to the outside and hug the idlers and sprocket. Backside of sprocket is getting shiny just from the running off the ground we've done in the shop. Sprocket and rear idler are centered nicely. Using a string to the front idler it looks near perfectly aligned too . As close as you can tell with our simple methods anyway. My only idea left is to drop the track, which will give me a better look at the idlers and cannon. Bottom rollers are worn but both sides measure the same. Rails are both the same height. I am out of ideas
HeavyEquipmentForums The chains are just following the groove in the roller in that photo. Could it be that the whole problem is the pre-worn old rollers?
It sounds like you've covered most of the bases. Have you considered swapping the tracks left-to-right and see if the problem persists. That way you could decide whether the fault was in the track frame or the track itself.
Cmark, I hadn't considered the idea that the issue might be the track. I am thinking dropping the one track is the next logical step, to better evaluate the idlers and such. I am also thinking maybe its our operating conditions. The plow had some bad bushings this summer that had it pulling to the right a little bit. The only symptom of that was the tractor would carve a loooooong arc instead of going straight. Had to correct direction every couple hundred feet. It pulled to the right just a little bit. That is fixed now, and I wonder how operating like that for maybe 100 hours could have created a permanent condition in the right track. ???? I am also thinking that turning the rollers around might help realign things. ????
I'm wondering if when your correcting your direction , is the track in question making a considerable amount more revolutions than the other. Can you have a psr come out and measure the rails , rollers and idlers while the rail is removed?
Even 1/16 on the end of the equalizer bar is too much IMHO. any movement on that bar is going to cause the track frame to toe-in under power. I'd suggest (after you've renewed the end pins & bearings) to do as others have suggested and swap tracks side for side to eliminate the possibility of the track being a root cause. Question: is the LH track running central on the track rollers at the moment..?
I have a rep from Equipment sales and service ( the major player in aftermarket undercarriage in this area) coming this week. I bought a nice set of calipers to take some measurements myself. Really want to get a read on the state of the rollers. The direction corrections i'm talking about are quick bump on the tiller. Just a nudge. While we are on that subject, the track runs to the outside regardless of whether I'm plowing or just tracking across the field, or even when the tracks are in the air. Left hand track runs centered, with no uneven wear showing.
watglen there are some guys on here I trust more than the people I deal with. Surely this will be sorted out. My neighbor is a PSR for Komatsu , I'm gonna question him on Monday or Tuesday. I've been thinking some again , just a complete shot in the dark , but if you remove the rail , stretch it out , is it possible the pins and bushings are worn on one side of the rail causing it to push outward? I've been to several auctions and never seen a machine favor one side like this.
I've gone back through the thread and can't see if you stated the manufacturer of the track chains. I have seen brands other than Cat that have had some weird wear patterns. I also don't see any mention of checking for dry links.
Hi John, The rails are CAT system one 2nd gen straight from Toromont. Have 1617 hrs on rails. I don't know the hrs on the rest of the undercarriage. I don't routinely check for dry links, probably every 250 hrs or so (couple times/year) I have never found any.
Psr should be out this week to have a look.
SystemONe - that's a twist we didn't know (or at least if you mentioned it before then I missed it) ....... I'd stick my neck out and say it's a problem with the particular track. SystemOne does all sorts of weird **** and I thoroughly detest the stuff. Stick HD undercarriage on it and have done with it.
Attached is an inspection report. I did the measurements myself. I may not have been trained, but it gives a picture anyway. Carrier rollers are the worst of all. Plenty of life left in this undercarriage. We removed the right carrier roller and ran it just to see if that helped center the track. It helped a little. The rails aren't pressed tight against the side of the idlers anymore. It is still up against the back side of the sprocket though. The carrier was centered, but the wear pattern has it grooved to the outside, should put a new one on just for good measure.
You seem to mention something about a plow and I take it then that you are using this machine in farming and not construction? The reason I ask is the right side front and rear track rollers are over 50% with the left side a lot less. Normally a machine doing a lot of blade pushing would were both front rollers more than the real while primarily ripping would wear the rear rollers more. I would not expect to see close to the same on one side front and back. I can seen dragging disks across a field and making left hand turns twice to hit the next row loading up the right side a lot more than the left side.
Yep you are right on all that. The plow is a tile plow (see pics if you can) for farm drainage. I am guessing that the first 6500 hrs of the machine's life were spent building those oil pump pads out in the bush in Alberta (There's a name for that kinda work???) The maint records say all the service was done out there, while the owner was in Toronto. After that I put the plow on it and that is basically all its done. The blade hardly gets dirty these days. So I imagine the front rollers got their wear out west, then we did the wear on the rears. That makes the most sense to me. CAT is coming soon to have a look. Maybe a trained eye will see something we haven't noticed(I hope)
Too bad the computer only counts forward and reverse on both tracks and not on each track. I'll bet the right side has an extra few hundred miles making those left hand turns.
I don't think pulling a tile plow involves much turning. I think a lot of it is just straight line pulling.
You say the current tracks have 1600 hours on them. Has the RH track behaved like it does for all those 1600 hours, or did something change at some point and after that it started to run hard against the rollers..? I'm going to stick my neck out here and say it's a dodgy SystemOne track that's the root cause of your problem.
Yeah, that right. For a normal dozing application, i expect a long straight push would be around 200'. For us, a long straight pull is 3500'. Nothing shorter than 150'. Then, because of the distance, you turn around and drive back to the start again to begin the next run. There is some turning, but it is the shape of the field that determines the direction and number of turns, so I suspect it is pretty even left and right. I THINK the wear began this summer. I noticed the right rail getting really polished and warm/hot kind of all of a sudden. At that time I don't recall seeing the amount of metal "burring" on the rail itself. At the time, it did a little testing, and found it was more a factor of speed than load: ie. tracking back in 3rd caused more heat than plowing out in 1st. If I had to guess, I would say it just started this summer. John, right now, IIRC there is about 2x the number of miles going forward as going in reverse.
Are you the person operating the tractor or do you have an employee doing it? You mention tracking back in 3rd? Is that reversing in 3rd or what.
I was going to comment on the 3rd gear issue also. Our tractors get 3rd gear both forward and reverse deactivated right from the get-go..........saves a world of hurt from operators who don't know any better and/or people in a supervisory position who simply don't care.
No no, sorry for the misunderstanding. I operate the tractor. 3rd reverse is disabled. Each tile run has a start and an end. When i get to the end, I turn around and 2nd or 3rd forward it back to the start, which is likely around 1000' drive. When I get there I turn around again, set up, and go. We do that all day every day.
Pulled the track off today. All I can say is the idlers are as close to perfectly aligned with one another as I can measure with string and straight edge. Idler bearings seem perfect. A better look at the idlers has them both about 1/4" off center of the sprocket. The idlers are outboard of the sprocket We pulled the track into an arc on the floor to check for snakey chain as its called. Pulled a string along one edge and found the arc measured 1.5" between string and chain at its furthest point (over 24 links) Thats as close to new as you are going to get I think. New chains would have a little curve to them. pushed and pulled on the front idler ( side to side) I wanted to know for certain whether toe in/out was even possible. Pushing on it and pulling on it to the point where the whole tractor starts to slide on the floor, you might see 1/8" difference between the front idler carrier and the tractor nose. Effectively no toe in/out at all. That undercarriage is as solid as it can possibly be. One question: We pushed and pulled on the track guide under the front idler. I would expect to see some rotation in the cannon by doing that. We couldn't make it swivel. It seems fixed and rigid. Is that right? I figured it was round for a reason. And the only other thing we learned was the sprocket idler offset. Still at a loss here. Rollers are worn heavily off center.
I would expect to see no discernable rotational movement of the cannon in a reasonably low-hours well cared for tractor. If there was any movement it would be measured in thousandths of an inch.
Agree with Nige. The cannon guides only get any real wear when the cannon is pushed back against the recoil spring. It's common to see wear on high hours tractors which have been in rock but not on machines which have had an easy life.
Nige, how would you define 'reasonably low-hours'? Under 20,000hrs?
On a D6R like that of the OP, probably under 10k hours.
I going back to you turning to the left a lot more than you turn to the right. You are turning 180 degrees at the end of the pull and then racing back to the other end of the field and turning 180 degrees again. Put a couple of counters in the cab one for right turns and the other for left turns. Compare them at the end of a weeks run time. The cannons can't turn as they are locked to the track frames as the rear where you see the round cap with about six bolts on each side of the undercarriage.
Maybe the bolts are broke in the end of the cannon on that side? Had it happen on a 7 once.
Ok, finally got this resolved, and I wanted to post the outcome here so everyone watching can get some closure. Toromont came out twice to assess it. Finally the top guy in undercarriage wear came out to have a look. He didn't see anything that is particularly worrying. He said it is common for tracks to want to push to the outside under load. Mine is favouring one side more than the other , but not enough to be concerned about. I learned a lot about the system one design. It has undergone 4 design upgrades to cure initial flaws. Mine is the final design. Some of the features of system one: The idlers don't wear, and last the life of the tractor. Because of this, they need to be resealed occasionally. The idlers don't ride on the rails, so the rails don't scallop like the HD design. The chain doesn't have pin bosses like the HD chain, so the roller flanges don't impact them as they wear. As double flange rollers wear, the flanges can get into the bushing seal area. With no pin bosses on the outside of the rails, guys would run the rollers well past worn out, which would start to tear into the bushings. For this reason, system one normally doesn't use DF rollers. The bushings rotate, so segments and bushings last much longer than HD. There is no bushing turns to do. He said, due to our non-abrasive soils, the rails would likely never wear out. The chains will be scrapped when dry pins become too much of an issue to put up with. Recommendations to maximize my track life. Swap chains side to side Continue using existing carrier Pull the shims out of the idlers. Its about time to do that anyway. Should cut down on vibration discard the 4 most worn rollers, and replace with DF rollers(the same ones used on the hd undercarriage) in the #2 and #7 locations. Re-sort the remaining rollers, rotate them 180, and install with best rollers to the rear. Thanks for everyone's input.
Follow up. Been running the tractor for a few weeks now. Chains are running centered on the sprocket so thats a good thing. Rail sides are evenly shined up. Seems like all is good for the time being.