Section for komatsu d20,21 and similar grey market dozers

I am trying to find out if swamp tracks on my d20p can be reversed or do they only go on one way

dirt_ripper said:

Krackerjack9,

Will you help me locate the 4 bolts we were discussing last time?

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their right there in that photo those little circles are just cork with paint on them I take the cork out and put some bolts in or seal with some silicone or maybe some epoxy

Krackerjack9 said:

their right there in that photo those little circles are just cork with paint on them I take the cork out and put some bolts in or seal with some silicone or maybe some epoxy

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So that's where water comes in..
I'm thinking of adding ripper to my dozer. Those holes might provide a good attachment points.

DannyO said:

Robert, Believe it or not, your problem is more than likely your alternator. The starter has an extra small solenoid that acts as a safety to keep the starter from engaging while the engine is running. It gets the power from the 2nd terminal of the alternator. If the diodes go bad on the alternator, it puts enough power (voltage) on that terminal to keep the starter from engaging when you hit the ignition switch. A simple test is to disconnect the the wires coming from the alternator. Of course, it's not so simple when you have the wiring harness removed. This is a common problem with these little dozers and if anyone has one long enough, they will eventually see the problem. Guess how I know!

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Sir,

Forum rookie and dozer rookie, so please forgive my ignorance. Having the same issue as describe above. Please elaborate on the test! I haven't pulled my wiring harness, yet.

VR
Tim

Been removing Eastern Red Cedar to build my house. Here’s a picture and maybe a video. While pushing the stumps and trees, a small piece of cedar wedged into the fan. I figure it snapped and fell just right and broke all but one fan blade. Amazon has the fan for $160 bucks. I’d prefer to go back with a simple mechanical fan, but can’t justify $160 bucks. Call me cheap, but I can put an electric fan wired in for free. Anyone know where to find one for less than a C-note?

All that being said, the fan with one blade has only allowed the dozer to jump 15 degrees warmer than it was before, using my laser temp gun. It will eventually lose that blade and kill my radiator, so it’s coming out later today.

Your machine your choice, don't look for many to tell you great idea on any of the above. Fan blade is cheap, burning up a machine because it was cheap to buy and do not wish to repair decently is not good sense.

I'm on my 3rd fan blade. I got both of mine from a guy in East Texas. He doesn’t come up on a search for that part number this time.

Found these guys with a quick search using the fan part number off my D20-PL6.

https://lifttrucksupplyinc.com/product/komatsu-forklift-fan-blade-600-613-0440/

The engine in mine is used in a bunch of forklifts as well and it’s way cheaper to buy forklift parts than dozer parts.

Theirs is $50. I used part number 600-613-0440. Yours may be different.


Where can you find an automotive electric cooling fan for under $50? Junk yard??

Installing an electric fan might be the way to go if you can rig up a way to take 12 volts off one battery of the 24 volt system and put in a switch. I've thought about doing that myself because mine overheats doing any real pushing.

If you go with the electric fan, please take pictures and describe your wiring strategy. I may be going that route.

dirt_ripper said:

Thanks for the info Krackerjack9..

Sharing my mods on pyramid shoe, to aid traction in dry land..

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Ten years ago I was reading up on adding more grousers back onto my pyramid tracks. I can tell you from long experience that tracks are meant to spin before the engine dies. I skipped every sixth pad when I added 3/8ths by 1 inch bars to mine. Yes it gives a rough ride. Yes it gives me all sorts of traction, but it is real hard on the little dozer that could. I don't have the slush box. Mine is just the 3 speed and if I had a lower gear it would need every bit of it. But boy can she push. Hard on the clutch though. Picture is of taking the tracks apart to rebuild front idlers and track rails. Gizmo with the blue handle is a 4 to 1 torque multiplier which beats a cheater bar in most cases.

DMiller said:

Your machine your choice, don't look for many to tell you great idea on any of the above. Fan blade is cheap, burning up a machine because it was cheap to buy and do not wish to repair decently is not good sense.

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I ride around with 2 mechanical gauges and I keep a laser in my pocket. I promise it won’t get over a normal operating temperature before I shut it down.

I have a hook up on free fans, temp sensors, solenoids. What makes running an electric fan a bad idea? PITA, yes. Bad idea, I don’t see your logic.

oldhousehugger said:

I'm on my 3rd fan blade. I got both of mine from a guy in East Texas. He doesn’t come up on a search for that part number this time.

Found these guys with a quick search using the fan part number off my D20-PL6.

https://lifttrucksupplyinc.com/product/komatsu-forklift-fan-blade-600-613-0440/

The engine in mine is used in a bunch of forklifts as well and it’s way cheaper to buy forklift parts than dozer parts.

Theirs is $50. I used part number 600-613-0440. Yours may be different.


Where can you find an automotive electric cooling fan for under $50? Junk yard??

Installing an electric fan might be the way to go if you can rig up a way to take 12 volts off one battery of the 24 volt system and put in a switch. I've thought about doing that myself because mine overheats doing any real pushing.

If you go with the electric fan, please take pictures and describe your wiring strategy. I may be going that route.

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$50 bucks is my jam. I could buy two and keep a spare, just in case I have another freak accident with sticks.

You just put a 24 volt fan on that bad boy. If you push from the front, you’ll diminish the power by 25%, but unless you spend some coin (which will eat your alternator) you’ll not find a decent fan that will match your mechanical fan and shroud. Do you have any damage to your shroud or space where it does not contact or let’s air bypass? Also, have you double checked your radiator for any dirt in the fins. Mine was fairly clogged when I bought it and I try and clean it off every hundred or so hours of use.

Shoot look no further... I've got both the 16" and 17.5" $70 delivered price in stock..

darinray said:

Shoot look no further... I've got both the 16" and 17.5" $70 delivered price in stock..

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I’ll measure tomorrow and give you a holler. Helping members that still post to forums is what keeps places like this going. Thanks bud. Doesn’t hurt you are perfect on the price. Hell, maybe I should have paid the $160 plus shipping that I was too cheap to buy.

Krackerjack9 said:

turns out my tracks are 5 joints to long and that my track adjuster cylinders need to be pulled out and see whats going on with them, anyone delt with those cylinders or is easier not cheaper to buy them and if so where??

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When I bought aftermarket track adjuster cylinders from the fellow in East Texas, the first one he sent me hadn't been finished on the inside. They sent me another one after some discussion but I ended up taking the second one to a machine shop anyway and had them rebore and polish the inside. You will need a big press to get the adjuster unit apart if the old spring isn't broken which mine was. Then when I did put it back together with a new spring I had to make a special stand to hold the parts while I had the machine shop with the 100 ton press compress the spring so I could get the keeper bolts started. There is a distributor here in Dallas who will sell you all the seals and Orings you need for the rebuild.

While you have the adjusters off the tracks pull your idlers off and check for wear top and bottom of your rails as well as the sides. I'm pretty sure mine was used for 2500 hours in a shrimp farm pushing seawater because the rails and idler frames were badly worn / rusted. I built them up with 7018 and ground them back to close enough.

You can rebuild all your bottom and top rollers if you can come up with some used ones to salvage parts from. When I bought my machine all the bottom rollers were shot and I replaced them with aftermarket. It was the roller surfaces which were worn out not the bearings. I used the guts of several of the least bad ones when I rebuilt the front idlers. All the track roller components are supposed to have several ounces of a fishy smelling oil sealed in them. The rollers have bronze bushings pressed into them which turn on a hardened shaft. There are sealing rings which are held in compression by big orings which allow the rollers to turn relatively freely while holding in the oil. Those rings are incredibly hard. They corrode thru from the outside and eventually leak all the oil out. I tried lapping enough of them to rebuild my idlers and several rollers and I can tell you better get a big diamond hone stone because they are made from something that don’t scratch. The Komatsu metallurgists really know their heat treat.

I made a mistake at the end of my rework on the rollers which I will pass on to you. I installed zerk fittings in the plug holes and injected regular grease into the ones which were empty. I am told now this was Bad Bad because the grease doesn’t get all the way to the sealing rings like the oil would. So I have tried making an oil injector which clips onto a zerk fitting. We’ll see how that plays out over the next 500 hours.

As far as water and contaminants getting into you brake/ clutch chambers yes. I found my biggest problem was letting enough dry air in to keep condensation from ruining the brake bands and clutches. I have left the corks out of the back plate and made sure I had a good gasket over the brake adjustment cover so water doesn’t get in there. Unless you are running the machine in 4 feet of mud or water there is no way it can get into those holes at the back of the gearbox. The air that circulates thru those bolt holes will keep the condensation from forming inside the chambers and therefore reduce rust.

Yes there is steep learning curve if you own and repair one of these. Get a manual and read it. It will save you time.

Thanks bud.....came in today

Anyone else have more damage than this on the front end? Pulling the blade and heating, pulling, tacking, rinsing and repeating.

Wow, what did you do?! use it for a chock on a 789 and forget it was there?

I've picked mine up by the blade to unstick it and not hurt it.

mitch504 said:

Wow, what did you do?! use it for a chock on a 789 and forget it was there?

I've picked mine up by the blade to unstick it and not hurt it.

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Looking at the rust that was there under the two or three layers of paint....I am going to assume it was cracked some time back and then the abuse I have given it over the last few months finally let it all come apart. After I pull it all apart, get it back to square and fish plate it, it will be stronger than it was from the factory. I’ve noticed a few other suspect welds and a few places where gussets will be added.

My wife told me I could break the bulldozer if I wasn’t careful, now she is gonna be right again. I don’t think it was 100% my fault, just glad it didn’t fold the blade up under it.

Lowbudgetjunk said:

Anyone else have more damage than this on the front end? Pulling the blade and heating, pulling, tacking, rinsing and repeating.

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Yikes, that's not going to grow back. Should be a factory recall and covered by warranty. Probably rusted from the inside out. Wholly cow man looks like some serious stretching, bending, pressing pounding, heating and some cursing thrown in for good measure to almost get it close enough to weld. The split on the inside curved part looks pretty catastrophic. Consider removing the entire blade. I wish you the best of skill, rigging and luck getting it fixed up.

GuglioLS said:

Yikes, that's not going to grow back. Should be a factory recall and covered by warranty. Probably rusted from the inside out. Wholly cow man looks like some serious stretching, bending, pressing pounding, heating and some cursing thrown in for good measure to almost get it close enough to weld. The split on the inside curved part looks pretty catastrophic. Consider removing the entire blade. I wish you the best of skill, rigging and luck getting it fixed up.

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If it doesn’t go back together fairly easily (relative term), I’ll cut the entire front end off an weld and plate both sides. Once the blade is off, I should be able to see the extent of the damage and make a great decision. Truth be told, I’m even more impressed with how well this dozer has done in spite of the prior damage that was there. Once it has been welded back up, I will have the same confidence that I had when I first got it.

I am looking at a D21a7 and noticed the track pads are not the same on both sides. Does it matter is the grouser rib travel is ahead or behind on the track plate?

Idiot put a rail on reversed