I have always been curious and never gotten a solid answer. I’m just wondering why caterpillar is the only company that uses the high track machines and what are the pros and cons.
When everybody is selling pretty well the exact same product, you have to build something different and then tell the customers forcefully and repeatedly that it's better. My opinion. There are some advantages in terms of being able to service the transmission and finals, and some gains in efficiency in terms of the power flow being all in the same plane as the engine crankshaft. What you gain though, I think you lose in terms of added weight, more moving undercarriage parts, track stress and wear. I hear that any day now CAT will announce they have an undercarriage that will hold up well for use on the high drive system.
it's so they can sell 4 idlers instead of 2...
Also, the chain is in tension at a longer length which accelerates chain and component wear. The rear idlers are more prone to wear and failure as a result of it wrapping the idler as if in reverse, but it's worse since dozers do their work in forward motion. So you're sending all that horsepower around the rear idler.
Nice graphic! :notworthy
So true, hahaha. I do think its a little easier to shovel mud out of a high track machine. CAT's small Dozers and the D7E went oval track. I wonder if the D6T+ will follow at some point. Maybe if they ever make an electric dozer in another size?
I noticed that on a sidehill application the C.G. of the whole machine is higher up, curious to get some real world operator feed back if they are less stable.
High tracks will not back up a slope anywhere close to what an oval will.
There has to be some good reasons and benefits to it other wise why do it.
Please explain why. In my mind the tractable surface should be the same, only pulling the track from a different spot. My old mind needs help figuring out the difference. I am assuming you mean straight up, not a sidehill.
I have operated both , and to me a high track seems less stable on steep ground. And like Shimmy said when backing up steep grades they seem to want to raise the back half of the tracks off the ground and spin. I do think the rails , pads and bushings last longer because there are more of them. One thing some other manufacturers should do is offer a seat that sets at an angle like the CAT.
I think the fore-and-aft balance of a high-track depends to a large extent what's hanging off the back of the chassis. Machines equipped with rippers seem far better balanced than those without. In fact some models even mandate the use of a rear counterweight if no ripper is installed.
I have a book on the history of Cat written by a guy who had help from Cat and even covers some experimental stuff that never went into production. It states that Cat went to the high drive to reduce final drive damage and to get the sprocket out of the dirt. Rick
One thing I appreciate on the high tracks is a smoother ride in shot rock w/ those oscillating track rollers. Any track type tractor will back up a steeper slope w/ a ripper especially w/ U-dozer. Mike
I wonder if the final drives of a high track has more leverage over the track its trying to get to move ,,verses on oval track design,,,mnnnn
I had heard Cat had pattened the High Track design, thats why no one has made one.... until recently when the patten ran out. Liebherr built a high track machine.
I'd like to see that machine up close... Im a huge Liebherr fan Lot of Cat similarities I see already.
Simon: I posted a picture of a brochure for one that I found online. Looks almost identical to a D10 undercarriage.
With the whole undercarriage able to oscillate and conform to the ground seems traction should be better too.
Rick, what is the title of the book?
I've been really pleased with the stability of high track machines on slopes. The pivot points of the roller frames being further forward seems to help the machine cope with uneven terrain compared to my old oval track 7 that tipped and leaned on whatever the rear of the machine was running over.
That Liebherr looks like a knock-off copy of a D10T in my eyes. Anyone who quails at Cat spare parts prices shouldn't buy one a Liebherr IMO.
Trouble is Clete track had a hi drive LONG time ago before Cat.
I saw a advert for a Cat hidrive set up for logging, with the arch out back. IIRC the frame was longer and the rear idler was further back, easy to build various track lengths is what I saw.
Also, why have the rubber tracked skid loaders adopted the same scheme ?
Ground clearance on CTLs would suffer as well as putting the hoses in a more risky position.
Nige, ain't that the truth!
I would love to put that liebherr through her paces,now that would be fun
And if right from the get-go it can't out-perform or at least equal a D10T it'll soon be consigned to the scrap heap of history ......... IMO Liebherr couldn't have timed it worse. They spent lord knows how many years developing this new model and then released it right at the point the open pit mining industry has literally taken the biggest **** in recent history.......
I wondered if a high track has better leverage over the track its trying to move verses an oval track design ?
IMO, sadly, they are on two back feet. As you rightly pointed out, the downturn, and the after sales. Liebherr aftersales are much fewer spread than the global might of caterpillar. That fact makes sales.
and yet mini excavators have not.....
Mini's final drives are a fair bit smaller eh?
Which put's them even lower to the ground.....
Sprocket diameter dictates the height, the housing on my mini is comparatively smaller than the one on my CTL, relative tot the sprocket diameter. Also the ctl's final drive is longer axially, which is what I was thinking. Their position probably helps with packaging the components of the machine as well.
Excavators have to have low drives in order for the house to turn above them. Mecalac makes a nice hybrid though. One factor on the CTL's aside from ground clearance and ease of service is the tracks. With a longer track you get a bit more stretch to absorb sudden shocks and more length in the loop means longer tread life.
Besides that, who would want a flat track CTL? I wouldn't.
I have been a skeptic of the high drive for years but over the years I have seen plenty of things that color the arguments against it. High drive life for the most part is about twice as long as oval tracks, both working in the same conditions. Then again the cost goes along with that. High drive is at least one and a half times as much money up front. I've seen high drives work slopes as well and any oval. The operators seem to be feeling the height and are more careful most of the time. The repair times are far less and actually I've seen fewer broken finals on high drives than what I've experienced over the years with the ovals. Not having to work with a hundred tons of pressure to free a sprocket was very high on my list a bunch of years back. I have wondered about the number of teeth engaged with the track over the sprocket and increased wear. Basically a high drive engages three teeth at any one time. Doesn't seem to make the bushings wear out any faster though. The oval might hit five or more. I have never understood why there wouldn't be a top roller installed on all high drives. I've seen plenty of well worn front idler carriers where the rails basically cut through them. All in all I think the design has proved itself over the years.
Mini ex's are an entirely different animal undercarriage wise compared to CTL's. Mini's basically rely on their undercarriage to transport the machine across the site. CTL's require the undercarriage to perform the work.
A long time ago, Cat had an explanation that went like that. They said that the articulation geometry of the high drive tracks gave better/more tractive effort pushing, compared to oval track articulation. (To me, if that is true, it means they give less pulling a ripper.) I don't actually know if the tracks pivot differently on a high drive. They also said that the rubber suspended, rocking, track rollers improved traction. I have no real knowledge about that, someone else will have to say if it is true.
I run both,and John C has valid points that I side with. Any extra costs with tracks or purchase of initial tractor are recouped over time with much lower costs on repairing them.Removing components and time spent on repairing them is massively quicker than conventional tracked machines,therefore,labour and downtime are reduced . Of course,you still have to buy spare parts for them,but with Cat,availability is second to absolutely nobody.They're also an abundance of other manufacturers making spares for them which helps keep the cost down if you don't ,or can't, use Cat all the time. As I can't afford to replace my dozers every few years,there is only one option for me and that's Cat. I do alot of final trim on batters etc,and I have no issues with hi drive tractors in the d4,5 and 6 range. Only used 7,8,9 and 10 tractors for dozing,pushloading and ripping.I have never had a big hi drive on a batter,so can't comment. As for ripping.......A hi drive is a no brainer
And there's the key Nige......they haven't actually released it yet. They've only built a few prototypes at this stage. The brochure is all still very preliminary. Who's to say when they will actually officially announce and release it.
I saw some photos of machines being shipped into (I think) the Hunter Valley in Australia. Might be nice for an update how they are going.
My son is in Coal in the Hunter. I'll get him to sus it out.
I predict D12, oval track, electric ... D7E x about 5.
I believe that despite the looks, the center of gravity is actually lower in the high drives vs. ovals. I know I am more comfortable on a sidehill with one. I like the visibility better as well, although Komatsu has redesigned their machines to move the cab forward which makes it comparable. Regarding undercarriage cost I cannot speak from personal experience, but I suspect that the majority of big applications such as mines would use something else if the cost per hour, or perhaps cost per cubic yard was higher overall with a Cat than the competition. I also believe that sprocket segments on the mid sized dozers will last through two sets of rails, which I don't believe ovals usually do. I have not had to pay for these components myself though so I may be speaking out of my posterior and will submit to the opinions of those who have actually been involved in the purchase and repair of undercarriage. Also, in my experience a D8R is much better balanced than a comparable oval machine and can back as steep or steeper than an oval machine if equipped with a ripper.
If you want to do some digging, look up CL Best. They actually had a high drive around a decade before Cletrac, and CL Best was one of the founding partners that formed Caterpillar, so................
I think it normally wears out two sets of segments to one set of rails. If the 8R doesn't have a ripper , then the oval track machine is better balanced and will back up a steeper bank?
Yair . . . A bit off topic but this issue of tractor "balance" I think is a little misunderstood. Sure, a tractor can work and be productive with out some weight on the back but what a joy it is to have a properly set up machine. Now, going O/T even further. On You-tube I see these large new fangled dollyless scrapers hitched straight to the back of (say) a D8. In order to keep a bit of balance they leave the blade on and even then at times I see the thing is struggling to turn . . . what a bloody wank. If they dropped blade off and got a dolly on that scraper the thing would come to life. I believe bladeless direct drive tractor with the idlers set high, hooked to the right sized dollied scraper with a good operator would lose some of these doughy modern rigs in it's dust. To take this a little further I watched a clip (can't find it now) of a tractor running on a bloody haul road . . . they seem to have forgotten you fall off the pile or bank as soon as the scoop has dumped and scramble out of the cut anywhere you can. Cheers.
I see your point, and I obviously worded that poorly. I have never run a D6 or larger tractor of any kind without a ripper, at least since the era of 9U, 3T, 17A, 2U, and 19A dozers that I have run; no, the 19A did have a ripper on it I think (tekoa maybe?) Come to think of it, with the high drives having the dozer closer to the front of the tractor, I believe that they have felt better balanced to me than say a D7G or D8H, which have always felt nose heavy, and would certainly climb steeper going forward than reverse. In my opinion the high drives were a little more equal as far as how steep they would climb forward vs. reverse. I have not had the opportunity run them next to comparable sized oval tractors to compare though, so I may be completely wrong (as has happened many times before).
Scrub, in 1976 I was running a little JD 450 cutting curb and sidewalk grade in on a subdivision in Bellingham, WA. The contractor that had done the bulk of the earthwork was finishing up and had one cat and can left on site. It was a direct drive D8, perhaps a 2U, and the operator and I would visit during lunch. I was young and trying to learn all I could, and he was near retirement age and enjoyed sharing his knowledge and good tales. There was one moderately steep side hill that he would come across after leaving the cut in route to the fill, and for some reason at about 3:00 every afternoon he would manage to lay the scraper over on it's side, at which time the spool of cable on the rear of the scraper, which did not have the big wing nut to hold it in place on the rod, would cascade down the rest of the slope. He would then recruit me to help him get the scraper back on it's wheels, and to gather up and rewind the cable back on the spool, and get it hoisted back onto the scraper. Fortunately there was no more than about five or six wraps left on the spool, so it wasn't a big chore. He did this almost every day that last week he was there, at about the same time, and I have always wondered if it was purely accidental. The older I get, the less I think so! Sorry to hi-jack the thread folks.
I know this is an old thread but speaking of high track how do you think the new Liebherr high track will do . I know in the US they don't have a big dealer network but this could maybe be a game changer ? I ran a 721 about 8 years ago and not a bad machine but a high drive hystat ? Just like to hear what you might think how it will be .
You know,for an old fart that spent so many years on a dozer it is a joy to read the input from others about the different views they have on the different concepts encountered over the years,and yes,I can still learn something.Don't forget,I started in the army as a teenager at heavy equipment school at Fort Leonard Wood in Missouri and then on a TD-18 for my three years in Germany which I have documented here with many pictures over the years.I have been involved in most aspects of earth moving ever since my army days and now since I got sick and can't do it any more but I can still learn.Keep it up guys.Thanks,Ron G
I'm guessing here. In reverse with oval drive design worn chain tends to lift off the rear driving sprocket so the primary driving tooth carries the track chain bushing at its tip. The discrepancy between chain bushing spacing, and sprocket spacing won't transfer any work to the next tooth until the first bushing is well up the first tooth. As the next tooth approaches, it'll touch the tip to the bushing until the preceding bushing slides down into the gullet between teeth. There's a lot of steel on steel sliding with only tangential contact, lots of pressure on a tiny area of contact. With high drive, the angle of approach changes somewhat to take some of this wear in reverse, and convert it to forward wear. Also some of the abrasive material falls away before reaching the sprocket. Shaft seals & bearings must last longer if isolated from some of the mud and snot. Pitch, or spacing is always different between sprocket, and chain, might having fewer gullets engaged at one time reduce wear caused by this discrepancy? Sticky snow or mud pack into the gullets of a sprocket effectively enlarging the diameter of the sprocket, and fouling the shape of the gullet. With high drive the chain gets some opportunity to lose some snot before engaging the sprocket. the bottom of the sprocket has an opportunity to dump the snow before it engages again with chain. A 100 ton crawler exerts considerable shock load dropping off a shelf. If the drive axle bearings, and shafts must carry this shock, that can't be good. Undercarriage replacement is considered an operating expense. Crawlers cost a lot to operate. Final drive failure is a bigger thing. It'd be tough to compare wear. It seems really big crawlers are placed in more abusive conditions than smaller ones less likely to have high drive. There's the old story of a doctor, lawyer, and engineer out hunting. They get lost, a storm comes up, and they take shelter in a cabin. The wood stove they find is 3' off the floor. They theorize why the obviously brilliant owner did this. One thought health advantages, one thought safety improvements, the third thought efficiency. The owner arrived in time to clear the matter up; "I didn't have enough stove pipe." Willie
i think high sprocket more smooth because track roller has bogiee and sprocket more proctect from material .
Heya folks, I've been curious about this for quite a few years now so I've spoken to many people about as well as having read up on the issue. Incidentally we are doing transmissions systems at TAFE and so I have access to quite some literature regarding this exact topic. Here's my 2c. The main reason is that a high track machine's final drives are isolated from impacts and shock loadings, improving final drive life. Additionally the final drive unit is not rolling around literally "in" the dirt/mud/dust. Because majority of our contaminates in earthmoving enter through seals etc it makes very good sense to lift this component up and have it out of the dirt. Again, less wear is the goal here. Secondly, when we consider the machine's balance (ignoring blade and ripper, and only taking into account the tractor) the main machine weight is over the tracks, not on the rear. This gives significantly better traction (allegedly, I'm a fitter not an operator). Obviously if it had a giant blade and no ripper it would be forward heavy, or a giant ripper and small blade would be rear heavy. Common sense prevails- balance the weight of your blade with something on the back. Furthermore the track frame can then be extended forward of the machine, rearward or both depending on the configuration. XL configuration has the front idler more forward than standard, XR has the rear idler extended rearwards and LGP has the idler in the same position as XR, while extending the front idler further than even the XL configuration. Because you can't shift around the final drive of an oval track machine this gives greater "from factory" customisation. From a serviceability standpoint being able to remove the transmission through the rear is certainly an advantage worth noting. Any way to improve serviceability is always going to save money in the long run over a machine's lifetime. Does this outweigh the additional undercarriage wear from having two idlers? That's for the bean-counters to figure out but we must keep in mind that a high track machine has more track plates to spread the wear around. Personally I cannot understand seeing any high track without a carrier roller but they are around... All that does is increase the track wear as it whips over the large space, especially at higher tractor speeds. From a physics standpoint we would lose some power because an oval track is pulling the track over itself in the same plane as the track is driving the ground. A high track is pulling it around and idler and then to the ground on a different plane so it's impossible that some energy isn't lost. I hope you all find this interesting, I've always wanted to be able to contribute to this sort of discussion If you want me to post pictures of some of the diagrams and paragraphs in my texts then I'm more than happy to oblige Peace!
just b difrent there all show haha na supose to keep the final drives outa the mud and rock ther alright but hard riping tuff going komatsu out do a cat any day
D6's are the norm in my area for size, when the high drives came out, most old timers then refused to run them, the complaint list was so long, if anyone actually wrote them all down, it would be a very large book to say the least. Mainly those young enough to change got used to them and after the old timers all faded into memory, the sales picked up and since CAT offered nothing else, you could say take it or leave it sort of philosophy, you could say sales of high drives rose steadily?? verses what, selling nothing at all?? I've ran both high drives and oval's, never saw firsthand all the benefits CAT has shoveled all these years, even after telling me how much better they are so many times I could retire several times over if they'd have paid me a dollar for every reminder of the benefits. If your running the machines daily, year in and year out, thousands of hours per year, those benefits might work out, for me who own and run many machines with few hours per year on each in the overall scene of things, I'd do a transmission and finals maybe once per machine in my lifetime, the disadvantages outweigh the benefits ten to one. As for other makers building high drives, first off the patents ran off years ago, as in decades ago by now, and yet only a handful of prototypes have been put out and not many went beyond that point, which speaks volumes to many us. Next is, if all these benefits are note worthy, why isn't every machine Cat makes, high drives including hydstat's in the smaller dozers, don't those machines have finals and motors as well that deserve to up out of the mud, muck and filth?? Wouldn't changing finals on those machines much better if they were up top verses down in the crud as well?? Or in the bigger picture wouldn't they be able to compete in the price of dozers and lose sales?? But above all else, lets not forget the famous, bragged about, trend setting, setting new horizon's, leader of technology to set the norm for centuries to come, of the great, slow speed high torque diesel engines on dozers?? Which also never went over industry wide, only to flop and fizzle out and now ever CAT's people say to not buy a dozer with those in, the repair costs are too high and parts are getting scarce, etc, etc, etc and not one other makers ever got on board to mass produce those style of engines or dozers with them in, but at the time, it was all the rage and a CAT exclusive..............much like high drives.................question is, will they do a better job of keeping the high drives alive over the old slow speed, high torque engines of years ago. But then again if I recall, after all the bragging is done, CAT is no longer in the over the road engine market either, leaving all those die hard truckers to wonder what happened to the best maker to ever build engines only to refuse to sell them to those same folks who spend their entire life bragging about them, to buy and run something else and where is all the bragging now of the industry leader?? those trucks run just fine with cummins, detroit and now many others doing the leading. But I guess when you quit making engines for the over the road market, that's the time to build a truck, powered with an engine that can meet emissions and bought from a competing company of CAT to power that truck.........but I know, I should just shut up and leave it alone, after all, CAT is the leader of the industry, and also the first the get out of those same self trend setting trends, did I hear and see CAT now makes an electric oval track machine?? where's the high drive on that, electric motor in the mud, much and filth, now that makes perfect sense..........to CAT, doesn't that machine have finals or do the tracks fasten directly to the motors, where are those bragging about all the track benefits of the high drives for the electric dozers?? But above all else, do the electric's start better in frigid weather than those famous slow speed high torque Cat exclusive engines of years gone by. And to think I can't order a brand new high torque low speed diesel in a new D6T, such a bummer, after all I was told of the benefits of those engines over the years, couple that to a high drive and I'd have thought, it would be an ideal dozer, the best of all worlds, both high torque low speed engine and high drive. But to answer your question, I think it gets down to a company trying to sell machines with their designs built into it and its up the customer to decide if those benefits are worth it or not is about the jest of it.
I think despite what anyone thinks sales numbers don't lie. Cat has the market share whether their machines are better or not. Another big reason why is Cat has the best parts back up and availability. It's not like their customers have bought a high drive, hated it and went to something else. There's a lot of repeat sales of high drives that are often more expensive than the competition. From my understanding Cat doesn't make the smaller dozers in high drive because they are more expensive to build/buy and aren't used in the same type of conditions as the high drives. You aren't going to be doing heavy ripping with a D4. Komatsu, JD and others have good machines too but Cat doesn't have the market share because users don't like their high drives. I was reading the history of the D10 and I think the 1st prototype was in 1970 so they didn't exactly rush it to the market.
the one thing I think Caterpillar nailed right with the hightrack is the angle of the lift rams . Nightmare to build sweeps for by the looks though . Fella retiring from a life time of contracting I bought some scrub rolling gear off said of the hightrack D4 that there's a hole to pull the transmission out of , real easy to work on and as he said it needed it . It also said of his Komatsu's that they are hard to work on but don't need much . Another point he was uncomplimentary on was the over-heating on the D4 , he said it was transmission related . He had fitted in front of the existing radiator another to simply lift cooling capacity that fixed the problem . Local D4E has an overheating problem to . Every thing has been pulled apart and checked to no avail , same capacity problem with the added disadvantage of not listening to those who can give them help .
The compact track loaders have the Cat high track design.
Hi D11RCD, Thank you , it was the best professional comment , what I hear.
It was not much more than a cut & paste from what Cat produced about 50 years ago when they introduced the high drive on what was then known as the D10 but is now the D11.
Hello Nige, I was born in those years. I didn't know the history. This summer I also managed to get a good condition D4H from Germany. (The running gear needs to be completely replaced) but the machine is in good technical condition. Can you perhaps get information about its history? 9DB04323
I remember reading that CAT summary of the change over to the high drives, back in the late 70s. Saw one of the early D10s in Salt Lake City mist have been around 1978. Boy am I getting old!
My first look at a high track Cat was in the late 70’s and they were unloading 2 of them, maybe 6’s. They were Army green and it was the Engineering Corps. They drove into the Exeter river that is now my backyard. They drover them down the river, one staggered behind the other, clearing trees and beaver damns. It was then labeled a State River and they put dams in, all the way to the Great Bay/ocean. Me and my brother followed them all the way around our property. That turned it into a first class trout river for 40 years.
I always wondered why vs std track. The big track loaders are std track
Build date is 1990-09-05
II especially like how they changed to high track, claimed it was the best thing since sliced bread, and 20 years later switched back......
I would love to have a new D5 high track but the $420K price tag with GPS is high step to take.
High drive seem to work better when the machine is equipped with bogie-suspended undercarriage. AFAIK that is D8 models and up.
If a dozer was used a lot would have to consider downtime and ease of repairs. I thought that was a big feature of high track dozers along with less shock load on the final drives.
High track dozers have their place but they will never push reasonably dry material, like a regular track dozer. They do offer some advantages for light grading, better sight line, usually do better in boggy conditions. Unfortunately the new and used prices for decent machines are almost double that of a regular track dozer.
Why would they struggle pushing dry material? I have a D6T XL VPAT and it does not struggle at all. Between the D6N and D8R that I ran for probably at least 10k hours, I really liked the high drive. I ran a D5M for a while but didn't care for it on side slopes, but it had the finger clutch disengagement and was miserable with the gap between declutch and brake.
Not so sure about that. Rented a D8R for 3 months on a project back in the mid 2000's and that was one dirt hogging SOB. Loved the fuel but man would it push. Material was a very abrasive chert with boulders. Same project we wore the pads out on a D6N at 500 hours - no joke.
Only thing I've found for sure to be true, a high track will not back up a steep slope as well as a standard track. Comparisons are 7H vs. D68, 8R vs. D155, and 6N vs. D61. Hmmm.......... Maybe it's a Komatsu thing.......
Does the high track want to dig in instead of climbing or doesn't have enough power? I know the County I was in preferred a Komatsu for pushing over D6N or JD. They said they could just boil the blade on the Komatsu and keep pushing. They bought the Cat though. About a $100K discount because it was for gov't. but another reason was rebuilt exchange components were thousands cheaper than having to buy new.
Oh yeah , once the rev's are up they do . Very quickly and on risky ground a bit hairy . Quite nimble the 155's for their size . The late model D7E could have had its drive anywhere and Caterpillar chose the oval design , says a lot.
Maybe it’s the material. High track dozers do not do well around here unless it’s prepared material. They work well in certain situations, I used one in a swamp, busting out stumps and was grateful for the better sight line but felt it lacked digging power over a regular tractor.
The swampy ground would lessen digging power on any dozer.
In my opinion, my experience with dozer work, I’ll just take a regular tracked dozer, preferably wide track, over any LGP, with the materials I have worked with. While they do have their place, I don’t think the price tag justifies them. Personally, I think the cool factor sells a few of them and keeps their used prices unreasonably high.
Yep, that's your opinion. When most guys need an LGP, that's the only thing that will work. To say that they aren't worth the money is a pretty ridiculous statement, IMO. Maybe you can do just fine with a wider track. I know I sure as hell can't, over half of the hours my 6N gets are in the swamp.
Feeling a little cranky tonight? I offered my opinion. The LGP craze is over.
Not a craze, at least not here. I would guess there are 5 LGP machines sold here in ND to every one standard or wide, probably more. I don't think I've seen a E-model Komatsu in any size smaller than a 65 ever here.
Thank You Masterwelder!
Here it's rare to see a D6 high track that isn't an LGP. The guy that cleared some bush for me had a JD 850J WLT that is kind of in-between a std. track and an LGP, wide long track. I'd guess he'd get a little longer undercarriage life than a full LGP but couldn't go in the swampy stuff.
Dozers are getting rarer and rarer around here. Were even up with excavators 25 years ago, now it’s quite rare to see dozers on clearing jobs. Seems most contractors would rather have 3 excavators on site.
For smaller new dozers around here I see more John Deere than most others. Just don't see the big jobs around here like in years past. Big jobs - the jobs and the dozers.
HY, we own a high track D5H, and i pretty much can service almost any component alone , everithing is at reach, i mean any component from TXM a track frame, as it was built as a modular machine. I guess CAT did a pretty decent job. For instance, heavy service, repair and replacing components in a track frame takes a day to open chain, remove frame from tractor, unbolt and bolt everithing back in, replace and istall components, tell me if u can ever do that in any new oval tractor in a day alone. Operation wise, well it does not climb well reward in places where one can´t drive sideways, but it drive sideways in the same place as any other machine, and if does not, its cause it slides , and when it slides one can´t do much with any dozer. But i agree in one poin´t if CAT would build a modular machine with oval tracks, that might be a very good move.
I remember when I got my first hours in a bogie suspension high track 8, and how it calmed down the big rocks. I watched others and whatever the maintenance cost, it was worth it to this operator. I would jump from the 8 or 9 to the 7G and bang, bang, BOOM, ouch. Building shot rock lifts with the 8 was not uncomfortable.
Bought the first LGP back in '21 - Next Gen D3 which is the old D5G/K. Still have a D5G XL and I can say the LGP is a much better finish tractor. Personally don't think an LGP tractor is a craze or a phase. Probably won't own another standard dozer unless it's an 8 and I doubt I will ever own an 8.
Same thing I said upthread. I'm guessing a set of rippers or a counterweight would solve this problem, I'd also guess the higher center of gravity is the reason they struggle.
I believe one of the design benefits was that despite the appearance, the center of gravity is actually supposed to be lower. Yes the finals are higher, but the engine and trans sit lower. This was the case when they first came out anyway. That would be comparing like an 8L to a 9G for example. Whether or not it still applies when comparing to new smaller Deeres or Komatsus I don't know.
Pretty normal for most of the dozers we sell and see to be LGP The narrowest tracks I’ve seen are on older track loaders The weird tracks are the occasional dozer that uses shoes cut shorter on the inside edge to give it a wider shoe without spacing out the track frames themselves.
Tracks on my Dresser TD7G are wider than standard. I can't make out the logo forged into the chains. More wear on the shoes than chains, so I guess they bought new chains, & salvaged shoes from? Shoes rubbed on the blade angle cylinders. I added thick plates to the sides of the C frame to guard the cylinders, and I cut an inch off the inside end of all the shoes. I worried about an inch different from the chain if it would cause accellerated wear. The parts manual offers 17" shoes offset, 7.5" inboard, 9.5" outboard. I'll guess Dresser engineers felt it'd be OK.
Maybe because they can sell more track parts, you know it takes more links and pins and shoes.
Here in the UK,std undercarriage tractors dissapered in the early 1990’s unless on D8’s and above.