Section for komatsu d20,21 and similar grey market dozers

[earl1957]

Sorry Idid it again my typing sux I'll try it one more time (p31d)kamoksu track loader.I think I got it right this time.

 

[toolbox]

hey all , new here , nice site

like a few others im here for info , and probly steering clutches.
Darrin , can you explain my serial # problem ?

decals say d21 - , tag says d21a-6 - 71855
has d20 6 71855 stamped on l/s rear

machine has 2 speed power shift .

yes its grey mrkt from co in texas , but been good machine for 5 yrs
been sitting for 2 now , need to get right

thanks , keith

 

[Frank Dozer]

Hello Larry,
I'm back in town again. Your pictures are fantastic !!! I'm going to get quotes on steel for the ROPS this coming week and I'll post pictures from start to finish. Thank you for the pictures!!! I almost forgot, my dozer is a 1985 Komatsu D21A-5 with a 6 way blade and only 1800 hours and I store it inside. This week I'm also going to start to design the 3 point hitch and I plan on using your recommended 3 hydraulic cylinders and 3 lever ......valve. It'll take me awhile so be patient. I specialize in curve balls, so any more you can think of, go for it.
Frank

Frank,

That three spool valve is going to need some fittings.
Get two of these for the in & out: SAE 8M x 3/4 NPTF 90* SWIVEL

Then for the work ports to the cylinders- are you going to use quick connects so you can remove the TPH assembly? or are you going to hard plumb it for a more permanent installation? Obviously the fittings will be different for which way you go. I suggest using 3/8" id hose max. There really is no need to have huge ID hose going to the cylinders as they will not be cycled very often, flow rate or heat build up is not going to be an issue so you might as well save costs by using the smallest ID hose and fittings possible. The valve takes SAE 8M fittings Here is a link to the SAE 8M fittings and adapters: CLICK HERE
These are the quick connects CLICK HERE

Larry

 

[darinray]

Hello Keith,

The stamp on the rear is always stamped D20 so just go by the tag. Hope this helps.

Darin

hey all , new here , nice site

like a few others im here for info , and probly steering clutches.
Darrin , can you explain my serial # problem ?

decals say d21 - , tag says d21a-6 - 71855
has d20 6 71855 stamped on l/s rear

machine has 2 speed power shift .

yes its grey mrkt from co in texas , but been good machine for 5 yrs
been sitting for 2 now , need to get right

thanks , keith

 

[darinray]

Earl1957, Do the steering lever pull back the same distance? If one side of your machine stops pulling then you may have the linkages not correctly adjusted....clutches are in oil from a leaking seal....how was the outer drum when you put teh clutches in? Were the groves chewed up from teh clutch teeth?

Darin

Just read your past post.. We need to know for sure what model you have because the D31 depending on the years are wet clutches so my statement about the oil thing will beout the window. Let us know

 

[keitho]

My experience tells me a new starter will be way over priced, somewhere in the thousands of dollars Something that should normally cost 150 is marked up at least a 1000%. I highly recommend the started be removed and taken to a rebuild shop to have it repaired / re-wound.

Larry

i hear that
the water pump went out on my d-20 a few years back and komatsu wanted $550 for a new one
a outfit in portland oregon rebuilt it for about $125
still spendy but a lot more reasonable

keith

 

[earl1957]

I think I must have y'all confussed.The d31 is the one with the starter problem,it's the p21d-6 with the clutch problems.When I bought the dozer a couple of years ago it had problems on one side.It would'nt stear at all on the one side and had been like that for a long time the man said.Maybe as long as 2 or 3 years the man said.I know this to be true becouse the side that would'nt stear was a 100&10 per cent worn out and the other was 90 per cent new.When we got down into it the big berring that pushes the clutch fork had came a part,hence being the problem.The clutch plates on the bad side were worn completly out along with the sprocket,rails,and rollers.I rebuilt the entire bad side and bought one stack of new steering clutchs.I stacked them one from the good side with one new one and so on till I had both sides.That gave me one new clutch plate and one 90 per cent new staggered for each side.I replaced the bad berring,I did'nt check the tention on the springs in between the clutchs plates and I guess I should have but did'nt.The teeth on the clutch drums looked good.I relined the bands on the break drums.On this model the clutchs are dry.But sence you mention something about a sill leaking,I don't have one I checked,but after what you said I do have a control vowel above the bad side that leaks.I'm sure it run's down on that side and is getting on that steering drum.Could that couse the problem I've been talking about?I never thought about a little oil on the clutch drum and a dry clutch at that.Would that couse that one side not to pull when in a bind?If that is the problem would break cleaner spraied on it while it runs corect it?Someone please give me some input on how to go about fixing this.I'm thanking anyone in advance for their help.

 

[darinray]

If the clutches are all oil then yes it will cause it not to pull but I was actually referring to the steering clutch release cylinder leaking or the bevel gear seal leaking. The oil from the control valve I suppose could get inside but...... If the clutches are oiled up the brake cleaner won't even be able to get to them unless you take them apart again. Check your oil levels on your machine to determine where the oil leak (if there is one) is coming from.

Darin

 

[Danny B]

Battery conversion

I finally got around to attempting the conversion of batteries to US standard size batteries. They fit like a glove. That means the fit is almost as tight as a well fitting glove. I will attempt to post pictures. Hope this comes in handy for someone who hasn't done this already.
Well, it looks like it won't let me post pictures.

 

[richied]

can i get a little help im new to this

 

[richied]

i am looking at buying a kumatsu dozer . the man has been honest to me . he says at first the steering is not good , but in a little bit it starts working good.

 

[richied]

I have a question for those who work on their own Komatsu dozer. Where do you get your parts? A Komatsu dealer? Are there any other options. I have a D20P7 and can't find anywhere to buy parts. Help

brandies equip. louisville ky or evansville ind.

 

[richied]

kumatsu dozer please help

im looking at buying a d20p and the man told me at first when u start moving the steering is not good but after a little bit it works fine . anyone have any replies or input.

 

[shouldabeen]

what would a blade for the D-21 cost? its bent at the top between the arms. Any suggestions to get the pivot ball to take grease. yeap tried heat and new inserts still nothing.

 

[keitho]

im looking at buying a d20p and the man told me at first when u start moving the steering is not good but after a little bit it works fine . anyone have any replies or input.

hey richied
i have a d20-p also circa 1990 or so that i got about 10 years ago
the steering seems to disengage the final drive on a side before it applies a brake on that same side and it appears to be done via a dry clutch pack that looks kinda like a automatic tranny clutch pack but run in a dry enviroment
i think if it sits awhile, the clutch pack kinda rusts? or seizes or some such as if i let my machine sit for 4-6 months or so then the steering is lame and appears to improve with use
not saying this is the absolute fact regarding steering but it appears that way to my lame a$$
btw: theres a fellow on this site that seems to know about the steering system and has parts for that,darin ray ? i think as i'm a new poster myself and can't 100% remember

keith

 

[richied]

thanks were going to look at it tomorrow.this guy is just selling it for his in laws and he has one just like it and he said his does the same thing.

 

[GuglioLS]

Hello Larry,
I'm back in town again. Your pictures are fantastic !!! I'm going to get quotes on steel for the ROPS this coming week and I'll post pictures from start to finish. Thank you for the pictures!!! I almost forgot, my dozer is a 1985 Komatsu D21A-5 with a 6 way blade and only 1800 hours and I store it inside. This week I'm also going to start to design the 3 point hitch and I plan on using your recommended 3 hydraulic cylinders and 3 lever ......valve. It'll take me awhile so be patient. I specialize in curve balls, so any more you can think of, go for it.
Frank

Hello Frank.

Glad to see you made it back safely. Fabricating a ROPS and TPH for your D21 from scratch are two very ambitious projects. I'm glad you found the pics of my ROPS to be of some help. No doubt it will take some time to put everything together. Nevertheless, I look forward to seeing pics of your progress. I can't help but wonder if it should be documented in a new separate thread so as to maintain some continuity and be more seamless to follow? What do you think? I see no reason why you cant start your own thread that is focused on a ROPS build, for that matter start two threads, one for the ROPS and one for the TPH as they are two distinctly unique and important projects that many may want to follow along, be able to look-up and refer to for all time. But hey, what do I know?

Larry

 

[keitho]

I see no reason why you cant start your own thread that is focused on a ROPS build, for that matter start two threads, one for the ROPS and one for the TPH as they are two distinctly unique and important projects that many may want to follow along, be able to look-up and refer to for all time. But hey, what do I know?

Larry

while that may be true
it is nice to have most of the micro komatsu stuff in a thread of it's own so folks like me can find it
but then that is just my opinion

btw: loved reading your tph stuff
that little round plate on the back of a 20-21? is that a pto access?


keith

 

[GuglioLS]

Hi Richied,

Keithio is spot on about the steering and drive clutches on these D20's. My D20 does the same thing, even after sitting for only a couple weeks. Sometime the steering breaks are locked up, and I have to pop the clutch at high RPM's to break it free. Other times, the clutch disks are frozen together and it will not dis-engage, so when I pull on the lever the breaks catch but the clutch does not dis-engage, it will not steer left or right and bogs down the engine when I pull back a level. To remedy that, I rev it up, pull back hard on both levers, put it in gear and pop the clutch. After everything is broken free, and driven around steering to the left and right for several minutes it operates like a new machine.

Now that you have more than 3 posts you can attach pictures uploaded from your computer. After your pic is uploaded post it right away, I think the pics disappear if you wait too long between uploading the pics and submitting your post.

Pay very close attention to the condition of the rear sprockets, front idlers, track links, track rollers, track shoes, front idler, and how much room there is left to keep the tracks tensioned. Also look for hydraulic and or oil leaks. Drive it around for at least a half hour, then bury the blade into the ground while traveling in first gear, see if both tracks keep turning at the same rate. If one or both tracks stop or slow down, the steering clutch(es) are most likely shot. Is the exhaust clear after it warms up? Will it go full throttle and run smooth after it warms up? Just a few things I can think of to check.

Larry

 

[GuglioLS]

...........Snip................Snip.......
that little round plate on the back of a 20-21? is that a pto access?

keith

Hi Keith,
Sure would be nice, I'm afraid not though, I think it's access to a shaft and bearing for transmission assembly / disassembly.

Thanks for chiming in on the TPH & ROPS "to new thread, or not to new thread" So you like the idea keeping it all here? I understand that.

What's the P in you 20-P stand for? Is that power shift or something? How does that work?

Larry