Komatsu D20A-6 ?

   / Komatsu D20A-6 ? #1  

GuglioLS

Veteran Member
Joined
Feb 13, 2005
Messages
1,143
Location
Edgewood, NM USA
Tractor
Jinma 354, 1953 Ford NAA Golden Jubilee, Komatsu Bulldozer
I am looking to purchase a used Dozer for road construction on my property. The road will be diagonally cross cut up into the side of a hill that has Lots of rocks & loose dirt. I have looked as several dozer's over the years, mostly Komatsu's D20's & D30's none of which were in very good condition. Well today I visited my favorite used Equipment lot and saw this Komatsu D20A-6 S/N 68449. Of all the Dozer's I have looked at, this one seems to be in the best condition. Price is 12,500. I was hoping to get your opinions of what you think of it's condition and if the price is right. I am not going to rent as I want a dozer to do the road project myself and at my leisure. I may sell it when done or just keep it for future clearing, leveling, & maintenance projects. I do not know all the Dozer terminology so please don't laugh at me to hard.

Here is what I know is in need of some work:

Visual:
The hour meter says 1477, no telling how many times the hour meter has been replaced over the years. I know it's a fairly new hour meter as it's not faded like the Oil pressure gage.

Six Way Blade, works all six ways with little to no slop in the joints. Cutting edge appears in good condition.
Two of the left hydraulic cylinders rods for the blade are pitted, so there are some small hydraulic leaks. The cylinder rods & seals will eventually need to be replaced. Cost? for parts. I can do most, if not all work needed.

The right side cylinders are excellent.
Tracks are nice and tight and seem to be in good condition.

I test drove it:
Engine starts with just a few cranks, it runs smooth, no white or black smoke, Clutch seems fine, breaks work. Turns Left no Problem.

Right turns are another story, when pulling back on the steering lever ALL THE WAY most of the time nothing happens, if you wiggle the lever a little - then it turns to the right no problem. There are several linkages that move and may just be out of adjustment? Sometimes it turns to the right sometimes not, when it does turn, the right track is held tight so I don't think the steering break / clutch needs replacement? not sure.

Anyway here are some pictures for all you experts to take a look at and let me know what you think of it's condition and if the price seems in line with it's age and condition.

Thank you for your input -
Larry
 

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   / Komatsu D20A-6 ? #2  
I have looked at a lot of crawlers over the years, but lacked the courage to buy one. It looks as if it has had reasonable to good care, and no signs of visible abuse or leaks? The sprockets maybe an issue however; the teeth on them look pointed and worn, and you may want to check on the replacement costs? It is also my understanding if the sprockets are at the end of their life cycle; so are the pins and bushings involving the tracks? The tracks show no sign of sagging? I would spend the money and pay a "crawler guru" to check it out for piece of mind after the purchase; it will be money well spent. They can hide a lot of their deficiencies that our pricey! Have that both turning clutches checked also. If one is going bad, the other may soon be a problem also.
 
   / Komatsu D20A-6 ? #3  
Hi Larry,

It looks like a recent paint job. That always scares me because I worry that they are hiding something. Same thing with the hour meter.

The sprocket looks really good. No points and it even looks flat at the end. I don't know what machmeter sees that I'm missing, but you're good to go there. The rails look like you have plenty of wear left on them too.

The bushings are your biggest concern with the tracks. You have to feel those with your hand. Are they round, or wore out on the sides? Have they been turned and is there a good side and a bad side?

That can be expensive if you need to replace them. Having them turned is a few grand, replacing them can be twice that.

One test to see how the clutches and final drives are is to bury the blade and keep pushing. If you can spin both tracks evenly, that's a good sign. If one track spins and the other doesn't, or they spin at a diferent speed, that's bad.

The price seems about right. I was originaly looking at those dozers myself. I saw them from $8,000 up to $20,000 depending on age and hours.

I ran a JD 450G on my place for awhile and realized it was way too small to do what I wanted. The D20 is allot smaller then the JD 450, so it's gonna be even less effective.

Some of the problems I had was being able to dig into the dirt. The tractor just wasn't heavy enough to break through hard packed clay. My neighbor has a guy working on his place with a low track Cat D5. It's a much smaller version of the high track models, but I don't know the specifics. His dozer is also too small to dig in the clay. They had to bring out a trackhoe to dig up the dirt, then use the dozer to spread and smooth it out.

If you have loose soil, then smoothing it out is what it will do well. Small dozers are not for road building, but for finish work and small jobs like residential pads and working in tight areas.

At 40hp and 9,000 pounds, I think you'll be dissapointed with it.

Eddie
 
   / Komatsu D20A-6 ? #4  
I have a 40 horse JD dozer for several years now. Eddies points are right on. The Komatsu may be grey market but parts are available anyway, might take a little looking.

Taking out trees w/a small dozer is a hassle. A backhoe of some sort is much faster. Although a BH on a hill has exciting moments as well BTDT.

The steering clutch may be an adjustment - since it sometimes works. dry/wet/steer clutches? Cylinder is a simple fix just takes some work, hydraulic shop can manufacture a new ram if necessary.

The hours on mine is 7700 + undercarriage was refurbished by the 20 year owner.

Tight tracks on a for sale machine is suspicious as it hides problems & the seller wants to make sure the tracks don't derail before it clears the lot.

Clearing rocks on a hillside with a dozer - it's best to have a bigger dozer than the rock. If your evenly matched weight wise the tracks spinout until there is enough rock weight on the blade - then the blade hooks the rock and the rock stops being pushed and starts rolling and your dozer starts mounting the rock. You don't want to be at the bottom of the hill with the rock & dozer on top of you!

The Cat forum was full of helpful tips on dozer operations: Welcome to ACMOC! I had no idea how to run a dozer (or a tractor for that matter) but figured a tracked machine was less likely to get stuck in the mud.

Post pictures when you get it home & be sure to practice on the flat & level a bit before tackling hillside clearing. Look forward to the finishing steps with loose gravel - will be the most unterrupted fun!
 
   / Komatsu D20A-6 ? #5  
EddieWalker said:
Hi Larry,

It looks like a recent paint job. That always scares me because I worry that they are hiding something. Same thing with the hour meter.

The sprocket looks really good. No points and it even looks flat at the end. I don't know what machmeter sees that I'm missing, but you're good to go there. The rails look like you have plenty of wear left on them too.

The bushings are your biggest concern with the tracks. You have to feel those with your hand. Are they round, or wore out on the sides? Have they been turned and is there a good side and a bad side?

That can be expensive if you need to replace them. Having them turned is a few grand, replacing them can be twice that.

One test to see how the clutches and final drives are is to bury the blade and keep pushing. If you can spin both tracks evenly, that's a good sign. If one track spins and the other doesn't, or they spin at a diferent speed, that's bad.

The price seems about right. I was originaly looking at those dozers myself. I saw them from $8,000 up to $20,000 depending on age and hours.

I ran a JD 450G on my place for awhile and realized it was way too small to do what I wanted. The D20 is allot smaller then the JD 450, so it's gonna be even less effective.

Some of the problems I had was being able to dig into the dirt. The tractor just wasn't heavy enough to break through hard packed clay. My neighbor has a guy working on his place with a low track Cat D5. It's a much smaller version of the high track models, but I don't know the specifics. His dozer is also too small to dig in the clay. They had to bring out a trackhoe to dig up the dirt, then use the dozer to spread and smooth it out.

If you have loose soil, then smoothing it out is what it will do well. Small dozers are not for road building, but for finish work and small jobs like residential pads and working in tight areas.

At 40hp and 9,000 pounds, I think you'll be dissapointed with it.

Eddie
Eddie: Thanx for correcting me; I thought the points on the sprocket were completely worn down and just the "nubs" left, making the sprockets ratchet under heavy loads? I know you have a lot of hours and experience, and your "da' man" with things to look for, and good advice also.
 
   / Komatsu D20A-6 ?
  • Thread Starter
#6  
Eddie,

Thanks for your analysis on the sprockets and rails. And for what to look out for on the track bushing condition. The new paint does not seem to be hiding anything other than maybe an old faded out paint job underneath it? Looks like they even went to the trouble to put new decals on it as well. I do not have any hard packed clay, so I should be able to push what I have intended for it. I did bury the blade as you suggested and both tracks spin at the same rate. Doing that sure does tear up the ground and make a deep trench in a hurry. I now see how one could get himself in deep trouble if your not paying attention.

Barry,
I appreciate the operation tips - fortunately I do not "intend" to push rocks bigger than the Crawler. But like icebergs you never know what lies just beneath the surface. The trees that are in my way have no tap roots, they spread out in all directions just under the surface. The soil is loose and mixed with small to large 100+ # rocks. In the past, I have pushed over several trees with my FEL attached to a 35 hp ~ 6000 # tractor.


One other question - Pyramid tracks vs the straight blade? tracks. What are the applications / advantages / disadvantages of both?

Thanks again,

Larry
 
   / Komatsu D20A-6 ? #7  
Pyramid tracks give you more surface area and are better in soft conditions. In your area, I'd think they would wear much faster without any added benifit.

Both will give you similar traction as weight of the dozer is what determines traction more then anything else.

One good thing about buying a dozer and finding out it's too small is they all sell pretty good. Hard to lose money on them if it's running and everything works when you put it up for sale.

Eddie
 
   / Komatsu D20A-6 ? #8  
Sounds like you are ready to get started.

Straight blade is a fixed tilt angle vs 6 way (or more) adjustability. To cut an angle shove some dirt under a track to set the dozer & blade at angle. Takes more space & time to accomplish. Less pins, bushings & hyd to maintain.

Tracks can be wide as well - used to float the dozer in swampy & muddy areas. Wide tracks wear fast in dry rocky work.

Another track type is the rounded grouser profile - the verticle fin on the track. These are found on tracked loaders - they spin easier to facilitate loader turning. I've seen a dozer blade stuck on these in place of the loader hardware at auctions.

Nothing like the sound of a dozers' deep throaty rumble while you are working changing the face of your land.
 
   / Komatsu D20A-6 ? #9  
Looks like a decent machine. Only thing I noticed that you didn't mention, the light mounts on the front. One appears to be bent to the side. Nothing there that you couldn't fix. Do you plan on keeping unit after you finish your road project? If not, might be cheaper to hire it done (no fun in that), but if you are going to keep it, might offer $10,000 and see how it goes. Good luck.
 
   / Komatsu D20A-6 ?
  • Thread Starter
#10  
Thanks for all the input and advice - I made a counter offer, it was accepted so we closed the deal.

Lots have happened since I took delivery - here is an update:

The biggest concern I had with the purchase of this machine was that it would not turn right when you pulled the right steering break lever. I read over the manuals I got and discovered a simple adjustment for the steering breaks. So I pulled off two bolts removed a small cover, tightened up the adjustment bolt a few turns and Shazam! The steering now works perfect ! :D
Here is a picture of my "new" (dirt cheap - used) Dozer at it's new home:

After making the break adjustments to both sides to make them even, I tested out the steering, here is a video of it doing a figure 8. The dozer is amazing, I have never driven or operated a dozer before. It will now turn on a dime:

I will need to drain all the fluids and replace the oil & fuel filters. I think this thing uses about 25 gallons of oil in various places :eek: I also need to reverse the cutting edge on the blade. After that, I think it will be ready to go. Oh need to set the valve lash - I doubt this has had any of the required scheduled maintenance.

Engine-----------------8 liters 15W40
Clutch case---------- 6 liters 10W
Transmission case 16.5 liters 30W
Hydraulic reservoir 33 liters
Final sprocket drives Left & right 12 liters ea (24 total)10W
Total 87.5 L or 23 gallons of various oils.
Fuel tank 60 liters (15.8 gallons)

All in all, this was a smoking deal, and I am fortunate to have found this little machine. I will need to practice on flat land so that I can develop skills in operating it safely and efficiently. The purpose of all this is to use it to cut a road to access the other 3/4 of my property.

Larry
 
 
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