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Section for komatsu d20,21 and similar grey market dozers

RRRancher

Well-Known Member
Joined
Jun 3, 2011
Messages
113
Location
Henderson, Texas
Occupation
Retired
I will defer to others who are more educated on the subject, but I think if it were mine, and it was doing as you described, I would loosen the brake band adjustment on the left side a bit and see if that helps. I'm guessing that if you are smelling it like that, the brake band is engaging when it shouldn't be. If the fluid level was low for the steering clutches, I would think you would have the same problem I had where it would bog the engine no matter which way you tried to turn. But since it is only the one side, I would think that it was the brake too tight on that side. Good luck with it. You are tougher than me by far if you can brave 8 degree weather. :notworthy I wimp out when it gets in the low 40's. I told my wife I would take her to Alaska some day. But only in the summertime. :)
 

g_man

Senior Member
Joined
Apr 21, 2011
Messages
321
Location
Northeastern VT
Occupation
Retired
I was wondering what happened back in in October when you were having trouble steering in reverse. Did you do something to fix that or did the problem just go away?? If there is any moisture at all in there at those temps it will be hard to get it adjusted. I am wondering if that is why it is acting so inconsistant. Have you been able to find a manual for it??
Those are some nice pictures you posted. Big country for sure.
 

jillmd

Member
Joined
Oct 11, 2012
Messages
21
Location
Alaska
Well I just got back from my cabin. I decided to remove the steering clutches and had success doing so. The first day was just remove panels and linkages. Then we drenched the steering clutches with PB blaster and let that soak up for a day. The following day we started to remove to the bolts and they all came pretty easy. Didn't have one really bad bolt. I believe the Penetrating oil worked. The clutch in questions came out with a lot of black powder. The second clutch barely had any powder. The hardest part of all this was getting the clutch covers off. I know Im going to have hell with putting everything back together. Any tricks on hooking up to the brake bands and brake band adjustment bolt?
Prior to all this work I put heat on the dozer for 2 hrs. Then I started it and smoothed out a spot with the blade. By the time I got done smoothing out the ground, the right side steering clutch was really squealing. I could barely move.
Anyways here are the few photos that I got so far.

437.jpg438.jpg439.jpgleft side clutch.jpgright side clutch.jpg
 

g_man

Senior Member
Joined
Apr 21, 2011
Messages
321
Location
Northeastern VT
Occupation
Retired
Thanks for the pictures and good luck. It looks like you are in for an interesting time. Keep us informed of what you do as much as you can so we can all learn. Hopefully someone will be able to help you out with some reassembly tricks.
 

Melson

Member
Joined
Feb 4, 2012
Messages
5
Location
Tennessee
We had already checked the strainer but did so again. Clean and does not seem to be the issue. Due to a death in the family things got put on hold until last week. Took the pump, modulator valve, and direction/speed/inching valve to the Komatsu service facility. They indicated the pump looked good and told me they had several D21 and D31 dozers come in a few years ago with simular symptoms. There was an issue with the strainer screen deteriorating and very small metal wire pieces getting into the modulator valve and causing it to stick.

Today we will take the valve apart and clean all the parts and use emory cloth to ensure the parts are smooth.

Anyone else hear of this?

Mike
 

jillmd

Member
Joined
Oct 11, 2012
Messages
21
Location
Alaska
I think I found the bad clutch disc. You can actually see through it. Absolutely no meat on the disc whats so ever.
Had to build a tool to hold the clutch so I could remove the bolts.

Left side clutch disc.jpgClutch tool.jpg
 

GuglioLS

Well-Known Member
Joined
Apr 5, 2009
Messages
59
Location
Edgewood, NM USA
Occupation
Electronics Field Service
Hi Mike, (Jillmd),

Nice tool you made to compress the clutch springs. I see your clutches are worn thin. Mine were not worn but rusted together in a bad way so I had trouble dis-engaging them as opposed to them slipping. Also both control shafts and needle bearings going through the steering case covers were pretty much rusted solid causing the breaks to lock up. The outside drum on mine was also rusted pretty bad and worn where the breaks engage. I replaced the clutch / break drums, all clutch discs, break bands, needle bearings, seals and control shafts that go through the steering case cover (both sides). However I did not replace the inner spline part of the clutch, I just sand blasted those clean.

After sand blasting I recommend using a wire wheel to smooth off the roughness left by sand blasting, then use an oxy –acetylene torch to lightly blue the metal, doing that will help slow down rusting and give a smoother surface for the clutch plates to slide on.

Amazing job you did taking it all apart in the freezing cold up there in Alaska, not to mention not much daylight this time of year either. You got to be tough as nails to pull that job off under those working conditions, nice going. No doubt you might have seen on page 100 where I did a similar break / clutch job? Except I did mine in June when it was like oh 75 degrees :D

Let me get this straight - You drove the frig gen dozer 12 miles out into the wilderness of Alaska in the middle of the frig en winter to rebuild the clutches and breaks right? :Banghead

You're not by chance related to any of those dudes featured on discovery channels "Gold Rush" are you? :eek: No disrespect, just wondering......
Keep the progress reports coming my friend.


Larry G
 
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jillmd

Member
Joined
Oct 11, 2012
Messages
21
Location
Alaska
That was almost rude about relating me to those fake gold miners. They would of paid some one to rebuild this **** or they would of left it. I know nothing about heavy equipment but I can turn a bolt. Larry I do appreciate everything you done for me, but this wasn't planned. I'm just doing what I can on getting this Dozer running. "****ing glory hole".
 
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GuglioLS

Well-Known Member
Joined
Apr 5, 2009
Messages
59
Location
Edgewood, NM USA
Occupation
Electronics Field Service
I know you didn't plant it that way. No disrespect or trying to be rude, Just trying to lighten up the situation a bit with some tong in cheek "humor" My apologies if in poor taste. I know the situation is not ideal. Your doing an amazing job under the circumstances and are to be commended. Those Gold "miners" ARE a joke, the whole thing is staged for "drama" I suppose. I stopped watching after I caught on to the gig they are trying to pull, it is so obvious.

Now for the sticker shock of buying parts....... I could not believe how ridiculous prices are, it's criminal. What should cost 50 is 500 and that's no joke! Get all that you can from the supporting independent parts supplier(s) of this forum.

Larry
 

randyaz

New Member
Joined
Dec 8, 2012
Messages
1
Location
oklahoma
Komatsu D40P-5 (Japanese)

My D40P-5's forward/reverse lever (mechanical transmission) has started "falling out" of engagement. If the dozer is on an incline and not under a load it slips out of gear. It isn't jumping out it simply falls out. It always felt like there was a detent or click when engaging it but now is smooth and I can keep in gear by simply keeping my leg against it. I pulled the deck up and inspected the linkage hoping what ever held it in gear was external to the transmission but it appears to be internal. I'm concerned that a spring or something has either fatigued or broken and will cause internal damage.

There is hardly any info on the internet on this model. I'm hoping a forum member can give me some advice on what is happening.
 

Matt2010

New Member
Joined
Dec 16, 2012
Messages
1
Location
Conway AR
D21A-7 running hot

My D21A-7 is runs right at the hot mark on gauge. Checked antifreeze and it is not low. Have cleaned radiator with low pressure water hose. Any other suggestions.
 

Treewinder

New Member
Joined
Dec 7, 2012
Messages
2
Location
Accomac,Va.
My D21A-7 is runs right at the hot mark on gauge. Checked antifreeze and it is not low. Have cleaned radiator with low pressure water hose. Any other suggestions.

Since it does not appear to be leaking or low on antifreeze, check thermostat to see if it is not stuck closed, see if fan belt is slipping, if all looks good, check out your thermo coupler, and the wire to thermocoupler that it is not shorted. Lastly look at your hoses, they may be collasping internally.

Ed
 

Treewinder

New Member
Joined
Dec 7, 2012
Messages
2
Location
Accomac,Va.
Any good decal suppliers out there?

Looking to buy a set of decals for my 1991 D21P-6; some years ago a friend borrowed the machine to clear a pasture of briars and in return said he'd paint the dozer. Not that it really needed it but he did and right over the original decals.

Most of what I see on ebay are newer gray decals, not the darkblue/black with white 21P. Searched in the forum and searched on the net but no luck yet. Appreciate any leads or people you have dealt with.

Thanks
Ed
 

rodneym45

New Member
Joined
Dec 21, 2012
Messages
1
Location
Arkansas
I am the new owner of a D20A-7E and I'm in the process of changing out all the fluids. I have done everything except changed the main clutch and final drives. What do you guys use in your main clutch? The manual calls for 10W, but I have not been able to find it. What besides 10W can I use safely?
 

JFoshee

Active Member
Joined
Apr 4, 2010
Messages
28
Location
North MS
I have a D31p-18. I have a bearing noise in the transmission. I am pretty sure it is on the forward/reverse shaft. Has anyone ever been in this transmission? Had this problem or one similar?Time involved to R&I? Time to rebuild if you have all the parts? Any special tools needed that a decent mechanic couldn't make? Any help is appreciated. Thanks.
 

illinoisboy

Well-Known Member
Joined
Sep 16, 2009
Messages
146
Location
Greenup
Occupation
contractor
Sprocket shaft

I have the d20p-6 and I need a sprocket shaft if anyone knows where to get one, I have a price from komatsu, but last time I got one I paid half of dealers price... But not having any luck locating one now.. Thsnks
 
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