Komatsu D20A-6 ?

[GuglioLS]

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

 

[machmeter62]

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.

 

[EddieWalker]

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

 

[BarryinMN]

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!

 

[machmeter62]

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.

 

[GuglioLS]

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

 

[EddieWalker]

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

 

[BarryinMN]

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.

 

[BTDT]

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.

 

[GuglioLS]

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 !
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 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

 

[GuglioLS]

I did a bunch od dozer maintenance @ 1748 hours on the proof meter. I am documenting this here so that I can print it out and and place it in my owners manual.

First thing was to replace the muffler - it was rusted out, leaking all over the place, causing soot deposits all over the engine compartment. The four nuts holding it on are shot. They came off no problem after heating them up with the Oxy-Acetylene torch:

Here you can see it rusted all the way through from the inlet to the outlet. There are supposed to be baffles in there:

Here is a side by side comparison of the old muffler and new one:

The gasket between the manifold and muffler is a one time use made of paper thin steel. So I made a new one out of a 1/16'" thick copper plate I had laying around:

I replaced those rusted out and torn up nuts with some nice new hardened steel ones:

This is what it looks like now :

This concludes the muffler replacement procedure.
Larry

 

[GuglioLS]

When I had removed the muffler, there was easy access to the valve cover. So I removed it to check the valve clearance. The rocker arm is pretty black with sooty oil deposits. I will change the oil now and at 50 hour intervals until this clears up.
The valve lash clearance is 0.3 mm for both intake and exhaust. There is a mark on the front pulley for TDC. All I had to do was rotate the engine using a ratchet wrench, then look for the #1 intake valve to open, then close then look for the TDC mark. In the manual it states I can adjust 4 valves at that point, the ones I can adjust are in a chart printed in the manual. After those 4 valves are adjusted, rotate 360* to TDC again, then set the other 4 valves. This sure beats rotating over and over for each set of valves. Most of the valve gaps were a little over 0.3 mm which is a good thing. I set them all to the 0.3 mm spec.


End of valve lash adjustment procedure.


Larry

 

[GuglioLS]

After the valve lash adjustment, Now it was time to drain the oil, remove and replace the oil filter. It takes a NAPA Gold 1206 oil filter:

I used Chevron DELO 400, 15W40 Heavy Duty oil for Diesel engines, it took eight quarts:

Then I removed and replaced the Fuel Filter with a Baldwin BF-954:


End of Engine oil, filter and Fuel Filter replacement.

Larry

 

[GuglioLS]

Next up was the cooling system maintenance. I had to crawl under the front of the blade to get to the radiator drain. So I blocked up the blade for safety:



I drained the radiator:

Then the engine block:

I FLUSHED & FLUSHED then flushed some more until the water came out clear. Then I closed off all the drain plugs filled the system with distilled water and added some coolant system flush and ran the Dozer for a half hour. Then I Drained that out and flushed again until the water came out clear again.

After all the flushing I had a pretty big puddle of mud
I then filled up the coolant system with 1 gallon of Fleet charge SCA antifreeze, then one gallon of Distilled water, then added 2 quarts of pre-diluted Fleet charge for a total of 10 quarts of coolant:


End of cooling system maintenance.
Larry

 

[GuglioLS]

By this time I am trashed - I look like a dozer mechanic - black with soot, grease, oil, and mud from head to toe with a hint of diesel.

Now I checked the track tension. Pretty easy just lay a board across the tracks and measure the slack in the middle. To set the tension there is a cylinder that is pumped up with grease, that in turn pushes the track farther apart making it tighter. If you make it to tight, just turn a nut and let some grease out.

Check out that spring:

Tracks tension is set to 30 mm slack on both sides now. All done with that. It was real easy.

Larry

 

[GuglioLS]

On the home stretch. Now it's time to remove the floor plate to check out all the gizmo's underneath. From here I adjusted the clutch pedal free-play, the break pedal free-play, and the Left / Right Steering levers free-play.


And one more adjustment - the Inertia Break band

The clutch on this is a "wet" clutch (submerged in oil) and there are massive gears in the transmission. So there is lots of inertia and fluid coupling between the clutch output shaft and transmission input shaft. When you push in the clutch, the fluid and inertia keep the output shaft turning (a bad thing). To stop the rotation of the output shaft when you push in the clutch, there is a break band around the output shaft called the inertia break. I adjusted the tension on the break band to stop the inertia when you push in the clutch to change gears:

Thats it, I'm done, the Dozer is ready for some action.

Larry

 

[GuglioLS]

One night a while back I returned home from another road trip to El Paso, TX.
It was a long drive so I was sitting on my butt for a while. When I got home I needed something to do so as to move around a little bit.
So this is what I did:
The Armrests on my dozer were falling apart so I made some new ones
Here are what the old ones looked like (Falling apart)

The "T" nuts were all rusted, and the particle board was disintegrating:

Had to use a bolt cutter to get the old bolts & "T" nuts off of the mounting bracket:

Larry

 

[GuglioLS]

Found some plywood scraps and cut them up into little pieces on a table saw:

Glued them together to get the thickness close to the originals:

Then aligned and clamped them together:

Before the glue set, I used a pneumatic Brad gun to tack them together (Brad let me borrow his) No really it's from...... well you guessed it, Harbor Freight. Except I buy the "good" HF tools


Larry

 

[EddieWalker]

Larry,

Congrats on the dozer!! And the video was fun to watch.

I know you already bought the new muffler, but next time, you might want to consider an auto muffler on the tail pipe. The muffler on my dozer sells for over $800 and was rusted through. The metal on it is fairl heavy, so I welded up the holes and the put it back in. I have a 3 inch tail pipe and found an inline muffler for $75 that works great!!!

You know the old saying??

The two happiest days of owning a dozer is the day you buy it and the day you sell it!!! I'm looking forward to my next happy day. hahahaha

Eddie

 

[GuglioLS]

A few of the corners needed to be rounded so they got cut on a scroll saw:

That saw works nice for curves as the blade is very thin and narrow:

Glued:

Then tacked together:


Larry