I have a 1996 Komatsu D20P-7E with pyramid (swamp) tracks and want better traction and lifetime without spending the $$$ for new grousers. Often I get into a stalled pushing situation where the tracks start spinning under load. The dozer seems to have plenty of power so its a matter of traction to increase the capacity. My property consists of clay like dirt mixed with small and large rocks. I was thinking of welding some rebar on the tops to increase traction. Would rebar be to soft and wear quickly? I though of rebar because its cheap.
I think welding bar stock to the peak on each pyramid would be better as the bar stock is square. The corners of the bar stock would probably dig in better. The rebar would provide more traction but probably not as much as the bar stock. You could also rebuild the peaks with some thick angle iron and that should help. They look a little rounded off to me. On edit: Oh yeah, and welcome to HEF. :drinkup
I know you don't want to spend any $$$ but ask anyone here and you'll find that owning and operating a dozer doesn't come cheap especially a wide pad. Operating those swamp pads in any kind of rocks will bend the shoes and probably break the links and pins. Have you done a track inspection to see where you are with wear on the link height and pins and bushings? Welding anything on those pyramid pads would be a bad idea in my opinion. Personally I would buy a new set of links and switch 'em out or change the pads for single grousers. You maye even find a dealer that may trade you out of the pyramids for single grouser pads.
Not disagreeing, I just don't know the answer but why wouldn't you want to weld to the grousers. Isn't that one way you can build up regular single grousers?
Those shoes are definitely worn bad. They are supposed to come to a point, not be rounded off. Welding material to bring them to their original shape will help to a certain extent with traction. The pyramid pads even when new won't get the same traction as normal shoes, so just be aware of that when you all options. I wouldn't be too worried about bending them since they don't look that wide and a d20 is pretty light.
Yep, the grouser pads would be better for my needs but thats the sacrafice I took for getting it locally for a reasonable price. The sprockets have been replaced, maybe the tracks are origonal since they are so rounded. I've only put about 20 hours on it, total hours are 2800. Last year when shopping for the dozer I saw many pyramid tracks with flat stock welded to the tops. My goal is to improve traction and hopefully lifetime. As Cat420 pointed out they are very worn altough I don't recall ever seen a new set to compare. Rebar is cheap but maybe not the right choice. I should visit a local steel shop and see what they have.
They look like this when new. The pads are hollow and the dimension is about 11/16" from tip to underside when new. In ideal conditions the pads will sink and the tips won't wear, on hard ground they will carry the machine weight and wear quickly if they can't penetrate like a single grouser pad.
So with the pads being hollow and the points worn off, welding something to them could cause the grouser to collapse? Is that why you said it wouldn't be a good idea to weld to them?
Based on that diagram I should measure them ASAP since mine look so rounded. I don't want to put holes in them!! So what is the conclusion about adding material to the top? I don't see a downside. Seems like some on "Machinery Trader" have material added. Look at first 2 on list. http://www.machinerytrader.com/list...=D20P-7&guid=9A0D55004EB047D998160384BD2267C6
I'm curious how much more flotation those pads have over regular pads the same width?
Is that style of pad more common on the D20-D21's than most? When I was looking around for a smaller dozer I didn't see alot with that pryamid pad, but I think every D20 and 21 I saw was for sale had them.:beatsme If they're worn out I'd think you'de not much to lose welding on some square stock. If they don't hold up, not much loss. If they do, then you get that much more work out of them. Unless, like Wulf mentioned, they're harder on you pins/links and those are in decent shape now. Machineman, what's your opinion of the dozer, overall?
I have seen a guy take a D3 LGP with those pads over a swampey area of muskeg ware no one could walk. Like others have said they are not made for hard surface work areas but nothing can beet them in mushey stuff.
Yup, I've always heard that if a machine like that is sinking a couple of inches then you aren't gonna be taking the same path on foot. I bet that D20 that Machineman has easily walks lighter than a man. Machineman, if the grousers do wear through then atleast you have 2 extra edges to dig in and give you traction. :thumbsup Jeff, I have to admit most of the smaller Komatsus that I have seen have the Pyamid style grousers also. Makes you wonder if its a Komatsu thing. :beatsme
So far the dozer is great. The only problem is my traction when pushing and that appears to be a pad problem. Of course this being my first Dozer I already want a bigger one but this one will do for rmany years to come. I have some deep mud spots and the dozer floats right over the top with those tracks and only weighing about 9000lbs. Thats what the pyramids (swamp tracks) are for but they seem to wear like hell on the rocks and hard pack. Me to, but wish I had a set of the 20" wide flat graousers.
I think the P designation means low ground pressure. I worked for a company that bought a D31P and it had pyramid pads on it. They had them swapped for regular pads before they hauled it to us. The dozer was used and had a new paint job. Looked like new. I took it out and made a push. Backing away from the pile I couldn't figure out what the heck was on it. I got off and walked up to take a look. It was a big slab of bondo. When I looked back at the dozer the blade was all dented up and had a couple holes in it. I laughed for an hour at that one.:lmao Gotta keep an eye on those Pesky Komatsu Dealers.:stirthepot
Machineman I think you could safely weld some hard facing on the tips to restore the worn material to the original or similar profile but welding rebar or grousers to the shoes to assist traction might cause the pads to break or twist the link... my guess only though.
I guess you don't have to weld a bar full width if you are worried about the load but that not my kettle of fish. From a weldor's point of view I'd give the re-bar a miss as it will be gone in no time. If you do decide to add bars use something harder such as 41/40 or 41/10. Pre-heat will be required to 100 deg C or 212 F. You can get a cheap heat crayon from your welding shop to indicate the pre-heat temp. I would root run the bar with a buttering up rod...usually one of those alloy (lollypop's we call them) rods that claim they can weld just about anything to clay. Then make your passes with something like Cobalarc, any good hardfacer or even just a good low hydrogen rod such as 7018. Lincoln are always reliable and they have great tech advice available.s Allow to cool in air if its not too cold (below freezing) otherwise post heat may be required. Good Luck.
Machineman - Nice looking D20! Short term I think that welding some bar onto the grousers wouldn't hurt but doing it right like Squizzy described would be the key to making it work well. One extra thing about the P models if I remember right is that they have a wider blade so you are probably trying to move more dirt too.
Swamp Tracks Hi, Machineman. Those pyramid track shoes - known as swamp tracks DownUnder - don't give quite the flotation of normal LGP grouser plates in soft going. BUT, they are a LOT more effective when the going is REALLY soft because they get far better traction than normal LGP plates when it really counts, where they can sink in the full depth of the pyramid and get their best bite. They don't do too badly for traction in sand either, although they do throw up a bit of sand to contibute to faster wear. I'd look at Squizzy's rebuilding advice seriously. The best bet would be normal grouser rebuilding bar in the appropriate size, then some sort of 'harder but not too hard because of the brittleness factor' square or round bar. I have rebuilt standard 2-bar track loader pads with concrete re-bar and it got us the extra 1,200 or so hours that we wanted out of the machine to complete the job. The top 1/3 of the re-bar disappears quite quickly but the wear rate slows down as the exposed section increases. The re-bar also has the advantage of already being sort-of vee-ed out to start with. And it sure gave it some 'toenails' when we first sent it back to work. Wulf's post about cracking the shoes through welding is valid, which is why Squizzy's post is worth looking at as it gives you a recipe for avoiding this. As Squizzy mentioned, it is not a good idea to let the welded shoes cool out too quickly. If cold is a problem in your part of the world when you do it, try to do it at least indoors in a closed workshop, with adequate ventilation, of course.
They aren't very worn at all!!They are also called "rice Paddies" on the Cats .I have used them extensively on 90B D6C long frames.They are excellent in muskegg and clay.If you are spinning .cut the throttle back and lift your blade a smidge;it will load up the tracks a bit .That s the tecnique we used on the 6;s.If you weld crap on them ,it will cause them to fracture and shorten the life of them.Some are actually made from cast steel,and dont like hard or frozen ground.
Good point.. I'm not sure if mine are cast or not. Based on my minimal welding experience cast was difficult and can crack.
I would weld on a section a grouser bar. Ive done a few this way both loader type pads, and swamp pads. I just use the 3/4 to 1 in grouser bar. Two different pads are the straight across pyramids and like on my brothers 3 hse a flat center section with a small back angle on each side. This type is a pain cause I have to preheat them and and bend them in my press a little. I havent had one break yet.
G,day Machineman. As you posted back a bit that second machine does have bars welded on...doesn't look like anything special but I'd still be treating it with some respect unless you can determine the actual steel type from the manufacturer. Grouser bar is best if you can find it from an earthmoving supplier.
mild steel bar worked great for me on clay Komatsu specs for the pyramid swamp pads say when worn beyond a certain point "build up with weld or replace" Heck if you've got to replace em anyway, then welding new grousers on ain't going to hurt a thing. It's not how pretty it is it's how it pushes. I welded 1 x 1/2 bar stock to mine and they work fine. I bought my old komatsu from an importer who I would guess buys from shrimp or oyster farmers in Japan. The trackframes are nearly rusted through in spots. I had to replace all my bottom rollers after using it about 100 hours. The same guy had all manner of Caterpilar as well as bigger Komatsus all with swamp tracks. I guess they are used extensively in Japan. Good luck with the welding job. It took me 2 days.
Some indicated the swamp pads could be cast metal. Did you weld from the center out?
Swamp pad grouser welding I used 5/32, 7018 rod, 1 pass, tacked on 3 or 4 then went back and welded solid. I started at one end and welded all the way across. Then after I had done one side on all 3 I got on the other side and made the return trip. My welds were 24 inches long on each side for a 26 inch pad. If you do the math dividing the drawbar pull of the machine by the cubic inches of stressed weld, and factoring in the moment across the base of each bar you can see that as the horse power increases the stresses go way up. Low horse power low stress. D20 has 38 Hp. =low horse power. I found that a piece of plywood was my best freind because laying on the track welding out of position is painful. A few of the pads warped a little (1/8 inch) but compared to what I started with it didn't matter. By the way cast steel is way more maliable than gray cast iron. The original pad material is a high manganese wear resisitant steel. The big boys go back with store bought stock. I couldn't see doing all that. Here's a link to one such supplier. http://www.dura-tuff.com/grouserbars.asp
Thanks for the info. I will probably put bars on all the pads to distribute the load to all pads/links. Sounds like I'm in for a long tedious project. :drinkup
While you're messing with the D20PL 6A While you're messing with the tracks, raise them off the ground with the blade. Stick a block under both front idlers and check your rollers for surface wear and bearing life. Those rollers start out with a 3/8 inch lip on them and when it wears to be 3/4 of an inch deep the flange is basically cut loose from the roller. Out of the 12 I replaced, one lost all it's innerds ( no bearing at all) one had it's flanges cut off, and the rest weren't far behind. I bought the book if you want the roller specs I'll scan em and email them to you. I got chinese made rollers at HeavyQuip which specializes in aftermarket componenets and repair of undercarriages. Very Easy to work with. Boy when I got to drive it after I put the new rollers on it it was smooth as glass (well almost, seeing as the D20 has zero suspension). I put up a couple of pics of the machine in the Thread "How much can be an undercarriage?". I wanted to ask King of Obselete how does he repair his old Cornbinder tracks which have to work at -45F without cracking? How does he keep the track rollers rolling when it's that cold? One thing I have noticed with this machine which had new sprockets installed before I got it is that every so often when I turn, a sprocket tooth will ride up on the inside of the chain and BAM it pops LOUD. I'm sure this not good for anything on the machine but unless I want to replace the both track chains I guess I'm stuck with it. I'm hoping that as the sprockets wear they will kind of get to be better friends with the worn out links.
I have the operator/maintence book with roller wear measurements. I haven't check it yet. Is your track tension OK? My book says the top droop should be 20mm to 30mm. I need to add some more grease to mine, there getting loose but no popping links. So far the only problem I have are: 1. Its it hard to get into gear, you need to some time play with the clutch, other times it slips right in. 2. The air cleaner cover palstic latch lips are cracked and broken. The cover can easily come off exposing the element. Furtunately the filters stay snug. 3. Traction needs improvemnt when pushing medium to full loads. I can easily get the swamp tracts to spin. I hope to remedy this with some added bars. Thes pads are hell on rocks!! 4. My headlight switch is broken. I don't use it at night anyway. Overall no major issues.
Inertial brake band behind the main clutch When I first got mine I had trouble shifting when it was cold. It would grind and not go into any gear. After it warmed up it would shift far better but still got grinding accasionally. So I read the manual and it said that the inertial brake spring on the output shaft needed to be so and so millimeters long. On mine before I messed with it, the brake band didn't touch the drum at all. I tightened it up so it would give the specified spring tension and wham, it shifted when cold. But wait theres more. Now mine is doing what yours is and going into gear sometimes and sometimes not. I assume I need to back off the spring tension slightly to allow the shaft to turn except when the clutch is mashed all the way down. Somewhere else they were saying that after adding oil to the tranny it shifted better but my oil shows full.
D20p Lurker here...first time post. I'm looking at a '91 model D20P tonight. New sprockets, 60% UC, 3000 hrs 6-way blade, brush cab. I want to start a little dirt pushing biz to keep me off the street and out of the bowling alleys and making a little money in addition to cattle. Any pointers?
R Leo. I had a boss that once said if you wanted to make a million bucks in the cattle business, start out with 2 million. He happened to own his own contracting company as well and said the same thing about it. Welcome to the site anyway, and good luck!
Welcome to Heavy Equipment Forums!!:drinkup Thanks for joining us!
LOL. That's about right. I always like to say that we're making a small fourtune in the cattle business and that we're just daggone lucky we had a large one to start with. Thanks for having me.
Welcome to HEF R Leo! :drinkup Post some pics if you get it. :thumbsup
When I got mine I did some research and found this: --Don't get a -5 or earlier, parts are had to get. --Get one with <4000hrs Here's some good info about the Komatsu D20's and D30's http://www.alaskaexcavators.com/Komatsu_Dozer_Models.htm Post up some pics..
Went to look at the machine last night...it's -6 which makes it 1991-ish, looks to be well taken care of. Starts right up when cold, no smoke except under a load and that's a black haze. Clutch/brake OK, steering brakes fine...left one seems to need more of a pull to work than the right, sheetmetal isn't bent-up, hydraulics seem solid, no leaks that I could see. Currently has about 3000 hrs on it. The sprockets have been replaced by welding on a new toothed ring. Is this common? Pins are about 60-70% according to the seller and they're definitely worn but I know zip about these things so I'm in the dark on that stuff. Here it is:
Bingo! machineman, your link answered that question. Thanx. "WELDED ON SPROCKET IS A NORMAL REPLACEMENT TECHNIQUE FOR D21/20 MODELS"
One more thing.... ...my tractor mechanic claims that Komatsu dozers don't stand-up well to operating in sand. Tony sez the steel in a Komatsu isn't as hard as the steel in a Case, etc...
Replacing worn out sprockets by cutting them out and replacing with a new sprocket set by welding is a long time practice, though not seen much these days on the bigger tractors. It is a little labor intensive, but on a smaller machine, probably no more so than dismantling the roller frame and track to get to the worn sprocket for a complete replacement. This has to consider if the rest of the undercarriage is in good shape. If you are going to be replacing rollers, idlers, and track assemblies as well, then you might as well replace the entire sprocket and the seals behind it. No sense doing a little bit, only to have to go back in a little later to do some more. U/C work is grunt work and is to be avoided at every chance by using proper inspection, maintenance, and operating methods. Good luck!
Komatsu D21 Howdy New guy here. Just got a used Komatsu D21P-6. Serial # 62196, and don't know the year, but think 1991?? Don't know much about dozers, but am learning. Haven't worked it yet, still trying to clean it up, fix little stuff, etc.... Anyone know a source for the hydraulic oil filters? Part #103-60-23240? I got the manuals from SSB tractor, and they seem like good ones. It has the pyramid tracks. Lots of hours....5142. Took the hr meter out to install an oil pressure gauge. Runs at 75 psi. Will be clearing some brush and stuff in South Miss. Thanks Pete
Welcome to HEF kc5gxc! :drinkup
Around here (Austin, TX) the Waukesha-Pierce house has Komatsu parts. Waukesha-Pearce Industries Inc. 16029 I H 35 Pflugerville, TX 78660 (512) 251-0013 There's another supplier in Houston but, I don't have the name or number handy. Will get it this weekend and post then.
Try these. I did look for after-market crossovers, seems that I remember using some, but the sites I checked did not come up with this number. I have some other paper work around for PM sheets on D21's, if I stumble across those they may give me a number that will help. Many of the Japanese machines, not being big sellers in America, never did have much crossover transmission or hydraulic filters available. No money in it for manufacturers. Good luck! The Distributors in Mississippi are: Komatsu - Distributor- 605400 LYLE MACHINERY CO. City: Richland Address: P.O Box 23087 Jackson, MS 39225-3087 650 U.S. Highway 49 South Richland, MS 39218 U.S.A. Telephone: (1)-800-898-4000 Fax: (1)-601-939-8440 Web: www.lylemachinery.com Lyle Machinery Co. Biloxi - 605408 12202 Oaklawn Road Biloxi, MS 39532 phone - 228-392-7100 fax - 228-392-7324 www.lylemachinery.com Lyle Machinery Co. Columbus - 605409 P.O. Box 7888 4715 So. Frontage Rd. Hwy-82 Columbus, MS 39701 phone - 662-243-2152 fax - 662-241-4582 www.lylemachinery.com Lyle Machinery Co. Hattiesburg - 605411 7515 US Hwy 49 North Hattiesburg, MS 39402 phone - 601-296-7556 fax - 601-296-7599 www.lylemachinery.com
I'll give Wix, Donaldson or Baldwin a call tomorrow because my D20P-6 uses the same filters. The Wix Internet database may not have a crossover but a 'warm body' could have the answer...they did on my '78 model, German-built, Deere 2040. I called Wix and got the numbers then went to the local O'Riley's and they had all the filters in Wix...even both the hydraulic filters.
Komatsu D21 Thanks for all the info, guys. I will check out Lyle Equip....I also have been all over locally looking for that hydraulic filter...there ain't no crossover for it. It's only to be had from Komatsu. I can cross the engine oil filter with WIX and also NAPA with no problem. Fuel filter is no problem. Hydraulic is the bad one...and I bet it costs, cuz it's a big filter. I go up to Hattiesburg every now and then. I'll see if they got 'em and get one from them. Just got thru changing all the oil in the dozer. It ain't too much fun under it with all the dirt and oil dripping on your face...ha ha ha. Guess I'm gonna go buy a wash down setup and try to get all that fire hazard out of the pans. They are full of pine straw, dirt and grease/oil...and it's packed all together like cement. Whenever I can do a regular post, I need to ask some questions about other things.... Thanks again for the help. Pete in South MS
Did an oil analysis on the new (to me D20P-6) and it came back with a clean bill of health. Wear metals well within the average for that engine and no coolant present in the lube oil. Slightly elevated silicon indicated a possible intake air leak that's bypassing the filter so, I'll look closely at that when it comes onto the property this Sunday. FWIW, the pyramid pads on my machine have had rebar welded to the tips as seen earlier in this thread. The majority of operation will be in sand and soft soil so that should work out fine.
I have ad21p-6 with the front idlier bushing worn out.It has lgp pyrimid track.My problem is finding the master pin.The Komatsu dealer said to look for a pin with a demple.My dozer chain pins are all have dimples the same size.I have had two mechanics try to find it and say they have never seen one like it.Help John T
My pyramid tracks apparently did not split by removing a pin but instead had a special bolt together link which used 4 of the pad bolts to disassemble it. Clean all your links real well and you will see from the side that one link has a kind of zigzag joint in it. That link connects the 2 ends of the chain together. The guys at the shop which worked on mine said they see very few of these type of chains because they are expensive and they are made for the Japanese domestic market. They were using a 3/4 impact wrench and a 6 foot cheater bar on the socket end to take the pads off the chain. Hope that helps. Just rereading this and I noticed you mentioned your front idler pins were bad. My front right idler started squeaking at me but I didn't hear it for some time because I'm a little deaf already and therefore I now use earmuffs (instead of 30 years ago like I should have but thats another storey) Anyhow so I went to move her one day and heard the squeaking without the earmuffs. I figured the bushings were dry. I pulled the filler plug out and cross matched it to an odd metric thread and drilled and tapped it to take a zerk. I did this to both sides so now before I use it I squirt some grease into both sides. So far so good. I guess you could do the same thing with all the rollers but it looks like they would get a lot more beat up then the center of the idler wheels. John
Re-guarding traction or dozers,Rebar is very soft ! May not be worth the labor and rod. What I have done is buy grosser bar it comes in all sizes and 20' sticks and is harden, Works very well in the southwest!
Pyramid Plates You really need to consider the whole track system ,before spending time on welding,etc.Those wide pyramid plates are constantly stressing the chains & wear will increase rapidly when using them in conditions they are unfit for. Those pyramid plates are excellent in snow & swamp areas,but are useless for most other applications.You will spend a lot of time & a bit of money to make a bad traction system only slightly better. Remember,by fitting normal 12" plates,you will extend the life of the chains by a good degree,as well as get a much better tractive effort & safer operating on slopes.I have used small Mitsubishi dozers ,equipped with good 12' dozer plates,to pull big logs out of flooded creeks.A swampie version would just sit & spin all day.... I think a guy called KTBaugh (on eBay) sells track gear for small Jap dozers. There are many suppliers in China/Asia too.Komatsu should also be of help. The small Mitsubishi , Komatsu & Hitachi dozers were often used in rental fleets in Japan.They were used in snow clearing & paddy /farming operations....& often sat in mud/snow for weeks without use....hence the bad track frames & broken bolts.In recent years,dealers like RB offload old Jap machines to places like Australia & USA in great numbers.These machines are great little dozers,if you can buy a tidy one.
What purpose were the pyramid type designed for? Newvbie here.
How do you find missing dimensions of given total surface area of a rectangular pyramid? also how do you find missing dimension with given volume of the rectangular pyramid? Got a big math project, your help will be greatly appreciated!!! THANKS!!
I have seen rebar welded on track pads on cranes for traction on ice. Welded on late in the fall cut off in the spring with almost no wear. Rebar is accually allot harder than most people think.
hi there new member hear doz anyone know where i can buy a full set track plates for my d21-6 in oz either 300mm or 3400mm
Ok any of the d20s or d21s that have pyramid tracks i would say 85% of them were imported from Japan, those dozers were mainly used in swamp type fields for rice and other soft ground over there,
The pyramid plates in the U.K. are now a scarce thing to see, we called them Apex Pads and were more common to see on Komatsu D50P and D60P Tractors, they used to be made of a Manganese type iron and not the best for welding a magnet would not stick to them, they were made for Swamp Dozers that very often had direct drive not powershift transmissions Komatsu called them a Swamp Shoe.
I beg to differ on the pyramid plates and floatation, because !! there are 2 sides of a tri angle pushed in the ground, therefore there is more ground contact so therefore the ground pressure must be lower per Sq in. Same reason they make air / oil filters with pleats in the paper element to give greater surface area for better efficiency and more filtering area. I have always found pyramid plates to be better than normal LGP grousers.