Section for komatsu d20,21 and similar grey market dozers

dgarner1988 said:

i am working on a komatsu d-20 p6 and wondering how to remove the steering clutchs on the right side, i have tore into it and have the final drive off the right side but i cant get the shaft out that goes into the clutch pack out to the final drive! any help would be appreciated. and what do i have to do to be able to start new treads?

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What's wrong with the dozer?... like most other multi-disc clutch/band type brake dozers the steering clutch has to come out through the top. There should be no reason to remove the final drive :beatsme

i thought that the final drive had to come off because the shaft goes from the final drive into the clutch pack. not sure though, htis is a trial and error thing for me. i have tank and everthing off and can see the clutch pack but dont know how to get it out. the dozer will turn right sometimes and wont sometimes it will chock the engine off if you try to turn right. not sure whats wrong just trying to figure it out.

Sounds like the RH clutch is not releasing and when the brake applies it stalls the engine but you should ensure that the pressure is OK and the release piston and yoke are moving fully.... before you start disassembly (ooops)

Once you are sure the problem is in the clutch assy then it can be removed by removing the rings of bolts on either side. You will need to rotate the sprocket to get at all the bolts then just lift it straight out.

thanks! i will let you know what i find!

Love Em

I've been running komatsu dozers for about 9 years and I think they are the best finish dozers out there!!! I've been running a 41E since 2000 and love it but my company took it the other day and is got me the new 51. Didn't think anything could compare to the 41 but so far I love it!!! BETTER VIEW!!!

Welcome to Heavy Equipment Forums MUDSLINGERS! :drinkup

well this is a long thread. actually didnt read any of it. but i am in the market for a used dozer to use on the ranch here and possibly make a little money with. i was thinking d3. but i want something i can pull with my 3/4 dodge cummins. is this what im looking for? a d 21?

My d20 has a 4D92-1 and the label says 38hp

R Leo said:

The deck plate (the piece under your feet) and seat plate (what the seat is bolted to) can be removed for full access to the brake/clutch linkages.

I don't know about the -5 but, these are the adjustment specs for the -6 steering linkages.

Steering adjustments


Hope this helps.

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anyone have a photo of the deck plates for a -3, someone removed mine and never replaced them.

Welcome to Heavy Equipment Forums dane busth! :drinkup

The new 51 is nice, and a great finish dozer, but the first problem i ran into is that you have to have a special permit to haul it here in oklahoma, not like my old 41 that I can just pick up and take anywhere I want, now I have to wait on that little paper to say i can move it!!! That's so much waisted time!!!!!! But other than that, I love it. I do alot of finish work, and guys I am telling you, I have ran all kinds of finish dozers and this has everything you could want in a dozer ( visibilty, power, and comfort.)!!!! JUST TRY ONE!

I am looking at a basket case Komatsu D53

A seller says his mechanic quit and left him with a partially repowered Komatsu D53 with a 4 way blade. He says UC is good and that it just had new pumps installed before the original engine cratered. He says they installed a 5.9 Liter Cummins truck engine, but never finished putting it back together. Tommorow I am going to go look at it and see if any of this makes sense. I can only wonder why the mechanic quit and if it had anything to do with how honest this guy is.
My other questions are what can you tell me as to good and bad points of that model machine besides the problem with it being 2 wide to move without permits.
Thanks
John
My other machine is a D20 with swamp pads. It has been relatively trouble free after I had the radiator rebuilt and the front idlers shimmed so the tracks would quit coming off. I did have to make special plugs for the front axles so I could use zerk fittings to force grease into my front hubs. It took a weird fine metric tread bolt. I drilled and tapped the ends for zerks and put the new grease fittings on both sides.
It started when I heard a weird squeaking noise in the right track one day when I was moving it without ear plugs. Turned out the front right idler hub was hot as a pistol. Not wanting to pull the track off to rebuild the bearings I opted for the lubricate and see method of repair. So far so good. Nobody has seized up and squeak is gone.
Below is picture of D20 getting new rollers after old ones fell off and just prior to me finding out the left fuel tank support was full of cracks and about to drop my tank off the back. Notice 1/2 x 1 mild steel bar I used as grousers. If I had it to do again I would have used fewer because now it just stalls instead of spinning. This is OK most of the time because I treat the old girl pretty easy.

hugger, how do you like that D20?

How I like D20

Motor is as smooth as glass until I stall it. Starter bendix is going out and It is a trick to start. Machine is a good size for working around farm but the transmission does not have a low enough gear for real pushing and machine is too light for heavy clearing. Angle blade can dig around stumps and I have dug out huge ash tree stumps with it. Requires patience and tenacity. Others have said this guy was designed for grading fill dirt and I think that is propably true. I have used it hard but fair here on our land north of Waco Tx. Swamp tracks wear out fast because of the much higher stress that the extra width grousers put on the pins, bushings and rollers. But the tracks let you put every bit of horsepower behind the load. I find pushing straight forward and back is much less stressful to the machine. It will not steer using clutches pushing a load because it just spins the other track. I steer using blade tilt.

See my post from 4-15-07 for picture of D20 in bottom of pond we dug.
Search by user name then reply title: price of parts and location, location, location

Hugger,With that being said would you do the D20 again or the D21?

Whether to D20 or not to D20, That is the question!

I believe the straight blade D20 I got was the most machine for the money I could afford at the time. If I had it to do again I would have prefered to have gotten a 6 way instead of the 4 way blade for a couple of grand more.

this is a great thread! I have an older 21P, I would guess to say a late 80's model. What a great little dozer. But I do need to get some work done to it. I have the same problem as others on this thread, that the machine will pull with the right track and turn left but the left track slips and turning right can sometimes be a problem. If I am reading properly, I can remove the floor plate and the seat to get at the clutches and brakes? And how do I get them out? Must I remove the final drives and the tracks or can they come out from the top? And what should I do to them. Also it sometimes takes an arm and a leg to pull the steering lever. I have a manual but it is a little vague. Any help would be greatly appreciated. Thanks James

Komatsu Clutch rebuild tool 791-417-5000?

According to my manual you need clutch compressor tool 791-417-5000. From the bad picture, what this looks like is something like a couple of discs and a threaded rod. Does anyone have a drawing of the tool with dimensions which one could then make a similar one from scratch? Remember the right jig is worth a thousand swear words. If anyone has a CAD drawing of the tool and they can figure out how to insert that image into this thread, it would be most helpful.
Another helpful hint would be where to get reasonably priced clutch discs for the D20-21 's Here in Dallas there is a local clutch and brake outfit that can reline the brake bands but I'm not sure about the clutch plates.
John

oldhousehugger said:

According to my manual you need clutch compressor tool 791-417-5000. From the bad picture, what this looks like is something like a couple of discs and a threaded rod. Does anyone have a drawing of the tool with dimensions which one could then make a similar one from scratch? Remember the right jig is worth a thousand swear words. If anyone has a CAD drawing of the tool and they can figure out how to insert that image into this thread, it would be most helpful.
Another helpful hint would be where to get reasonably priced clutch discs for the D20-21 's Here in Dallas there is a local clutch and brake outfit that can reline the brake bands but I'm not sure about the clutch plates.
John

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There's a guy selling rollers, sprockets and clutch parts on eBay sometimes.

Here's his current ad:
eBay

D21-5 starter armature burned up

as title sez, starter is shot. Took it to 'old school' starter/generator shop and they have no sources that supply replacement armatures for this starter.
Komatsu price for a rebuilt is $780 plus $280 core, and even with old starter you must pay core so it can be returned to Komatsu for evaluation and credit adjustment.

anybody here have a source for used parts?

TIA,
MikeK