kensmith69
Well-Known Member
Well im not going that fast so Ill try not using it much.
When you say valve spool you mean the valve itself needs work?
When you say valve spool you mean the valve itself needs work?
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Section for komatsu d20,21 and similar grey market dozers
- Thread starter rangerfreak
- Start date
g_man
Senior Member
Well that was bad luck. Collapse your track tensioner and push it back all the way. Use a come-along or a block behind your blade and angle it back or a tractor. Get it off the ground - if there is a hitch on the back block under it, or any place rear of the sprocket you can block will help get the back end up when you raise the front. Raise the machine off the ground with the blade. You want the track to be looped under the rollers. Get it on the top of the sprocket first. Then work it around - easier said than done. Good luck.
kensmith69
Well-Known Member
Got it done following your basic instructions.
Tensioner wouldn't go back and I wasn't sure whether I should take the grease zerk right out.
I just loosened it and after lots of playing around the grease started oozing out.
What would happen if I took it right out?
So anyway got it back on , work for a couple of hours and it fell off again.
I must have problems, right?
Both times it fell off when I was backing straight up.
Suppose I need new front idlers?
Are the available ?
How hard are they to change?
Tensioner wouldn't go back and I wasn't sure whether I should take the grease zerk right out.
I just loosened it and after lots of playing around the grease started oozing out.
What would happen if I took it right out?
So anyway got it back on , work for a couple of hours and it fell off again.
I must have problems, right?
Both times it fell off when I was backing straight up.
Suppose I need new front idlers?
Are the available ?
How hard are they to change?
g_man
Senior Member
Ouch. Hard to say what might be wrong.
When you go forward the bottom of the sprocket pulls the chain under the machine. So the chain is tight on the bottom between the front idler and rear sprocket. Everything, sprocket, rollers, and idler, should be lined up straight so the track won't try to come off. But if there is a misalignment the weight of the machine will tend to hold the machine down on the chain. Plus there is more stuff on the bottom as track guides. When you go in reverse the top of the sprocket pulls the chain tight over the top roller and idler making the top of the chain tight and bottom loose. If there is any misalignment the chain is more likely to pull off on top because you don't have the weight of the machine holding the chain in place thru the misalignment. That's why it comes off easier backing up.
Get the u/c wear specs and check your under carriage components. Chains, idlers, and rollers. Over wear is common but it might give you an idea where your trouble is coming from.
Make sure every thing is lined up. Make sure the track frame isn't bent cocking a front idler in or out. The top roller should be centered, same with bottom rollers. Are your chains worn so much or the front idler worn so much that the pins contact the center of the idler and cause the chain to ride up on the front idler. Raise the machine with the blade and watch the track run front and back. Maybe you can see why it is trying to come off.
Removing the tensioner zerk won't cause any trouble.
When you go forward the bottom of the sprocket pulls the chain under the machine. So the chain is tight on the bottom between the front idler and rear sprocket. Everything, sprocket, rollers, and idler, should be lined up straight so the track won't try to come off. But if there is a misalignment the weight of the machine will tend to hold the machine down on the chain. Plus there is more stuff on the bottom as track guides. When you go in reverse the top of the sprocket pulls the chain tight over the top roller and idler making the top of the chain tight and bottom loose. If there is any misalignment the chain is more likely to pull off on top because you don't have the weight of the machine holding the chain in place thru the misalignment. That's why it comes off easier backing up.
Get the u/c wear specs and check your under carriage components. Chains, idlers, and rollers. Over wear is common but it might give you an idea where your trouble is coming from.
Make sure every thing is lined up. Make sure the track frame isn't bent cocking a front idler in or out. The top roller should be centered, same with bottom rollers. Are your chains worn so much or the front idler worn so much that the pins contact the center of the idler and cause the chain to ride up on the front idler. Raise the machine with the blade and watch the track run front and back. Maybe you can see why it is trying to come off.
Removing the tensioner zerk won't cause any trouble.
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kensmith69
Well-Known Member
Worked about 4 hours today in rough country.
The tracks were binding up I could hear them but they stayed on.
Front idler has about as much meat as my finger?
Back sprocket looks new doesn't it?
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g_man
Senior Member
They both look good to me
darinray
Charter Member
Your inching pedal sticking is probably sticking on the swivel mount or mounts. Best to take cable off and check where it's hard to move.... A remove... clean... lube... and reinstall will get that baby free moving again. 
With the tracks coming off I can't tell by the pics of the condition of the bottom rollers.. Make sure the flanges are all intact. Before they come off can you see that the tracks keep loosening up? Also be sure to check side to side play in the front idler (shaft movement too) does it move up and down alot off the frame rail?
Good luck..
With the tracks coming off I can't tell by the pics of the condition of the bottom rollers.. Make sure the flanges are all intact. Before they come off can you see that the tracks keep loosening up? Also be sure to check side to side play in the front idler (shaft movement too) does it move up and down alot off the frame rail?
Good luck..
kensmith69
Well-Known Member
Front idler does move around a bit.
treylt
New Member
new to the forum and a first time dozer owner. I just purchased a D20p-7 and im wanting to change all fluids. There are 3 plugs on the rear under side of dozer one in the middle and one on each side. could someone tell me what these drain plugs go to? also what oil should be in the chunk at the rear of tracks? thanks
RRRancher
Well-Known Member
Welcome to the forum, treylt. The operator manual lists all the fluids that go in the various places on the dozer. If you don't have a manual, you can purchase one online at a website I linked a few pages back. I have a D20A-6, and I know what to use on mine, but not sure on your model.
Edit: I found the website again and here is a list of all the manuals for the D20 line.
https://www.tradebit.com/filesharing.php/search/0/komatsu+d20a
For normal maintenance, you will want the Bulldozer Operation and Maintenance Manual for your serial number. For disassembling and reassembling and adjustments, you will want the Workshop Service Repair Manual for your serial number. They also have a combo package with both of them.
Edit: I found the website again and here is a list of all the manuals for the D20 line.
https://www.tradebit.com/filesharing.php/search/0/komatsu+d20a
For normal maintenance, you will want the Bulldozer Operation and Maintenance Manual for your serial number. For disassembling and reassembling and adjustments, you will want the Workshop Service Repair Manual for your serial number. They also have a combo package with both of them.
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treylt
New Member
thank you for your reply. ill look for that post and try to get a manual ordered or downloaded. im in the process of pulling one of my steering clutches to rebuild now im sure the manual would be very handy
RRRancher
Well-Known Member
Well, don't count too much on the shop manual for that. It is not the best thing for sure. The pictures in the original manual were done very poorly, and it is difficult to see any details in them. And the instructions are written in, what some would refer to as, Jinglish. You have to think about what they are trying to say sometimes to understand them.
There has been lots of discussion here about pulling and working on the clutches. Some have uploaded some really good pictures of the process that will probably help you as much or maybe more than the shop manual will.
If you have a printer at home, I would suggest just downloading the manual(s) in PDF format, and if you need a reference in the shop, just print the page or pages needed to take with you. If they get dirty, no biggee.
Good luck with it, and let us know how it turns out.
There has been lots of discussion here about pulling and working on the clutches. Some have uploaded some really good pictures of the process that will probably help you as much or maybe more than the shop manual will.
If you have a printer at home, I would suggest just downloading the manual(s) in PDF format, and if you need a reference in the shop, just print the page or pages needed to take with you. If they get dirty, no biggee.
Good luck with it, and let us know how it turns out.
treylt
New Member
Thanks for all the advice. I've read most of the posts in this thread and found tons of useful info. I appreciate all the experts posting on here helping us beginners. I'll surely keep you posted. Can't wait to get the dozer going and start cleaning the place up. Thanks again for your help!
ffmloyd
Well-Known Member
Ok fellas im pretty new to this just bought a used D21p-7 and im looking to buy a book for it but for now i though i ask about some maintenance things. The dozer runs great has 2100 hrs but im having some problems with reverse ill list below and add picture.
1-Im unsure of parts look up because my tag only says D21p-7 and the part manual online RRR posted a few threads ago has several versions of the d21 How can i tell what the extra letter is in the model number
2- Also would like to know the year, my ser# is 78448
3- I need a list of capacities and weights of oils and fluids. ( i want to do a full service on it before i work it much)
4- Also need help determining where to check and fill these fluids (some are obvious like the motor)
RRRancher seems to be quite knowledgeable on these little babies!
when i find these things i intend on posting pictures to help other people because pictures are worth a thousand words.
below is a picture of mine.
5-Reverse sometimes will not go, but after working the power shift forward and reverse it finally goes.. i noticed a site glass on the right rear of the body behind the door that is very low.. is this hydraulic oil check or what. please explain
1-Im unsure of parts look up because my tag only says D21p-7 and the part manual online RRR posted a few threads ago has several versions of the d21 How can i tell what the extra letter is in the model number
2- Also would like to know the year, my ser# is 78448
3- I need a list of capacities and weights of oils and fluids. ( i want to do a full service on it before i work it much)
4- Also need help determining where to check and fill these fluids (some are obvious like the motor)
RRRancher seems to be quite knowledgeable on these little babies!
when i find these things i intend on posting pictures to help other people because pictures are worth a thousand words.
below is a picture of mine.
5-Reverse sometimes will not go, but after working the power shift forward and reverse it finally goes.. i noticed a site glass on the right rear of the body behind the door that is very low.. is this hydraulic oil check or what. please explain
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tpitt
Well-Known Member
My D21A-7 serial # is 78529 and it is a 1995 model.
ffmloyd
Well-Known Member
yes i did find this site that was helpful.
http://alaskaexcavators.com/Komatsu_Dozer_Models.htm
and this one
http://alaskaexcavators.com/D21P_Brochure.pdf
but does not specify the exact year. i figure the serial number might help.
I ALSO noticed the specs on the battery on the Brochure page says its 12v system. mine is wired 24v using 2 batteries and not one as stated,,, so i dont really know whats going on there.
http://alaskaexcavators.com/Komatsu_Dozer_Models.htm
and this one
http://alaskaexcavators.com/D21P_Brochure.pdf
but does not specify the exact year. i figure the serial number might help.
I ALSO noticed the specs on the battery on the Brochure page says its 12v system. mine is wired 24v using 2 batteries and not one as stated,,, so i dont really know whats going on there.
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ffmloyd
Well-Known Member
you can get a decelerator option here. http://alaskaexcavators.com/Komatsu_Dozer_Models.htm
ffmloyd
Well-Known Member
ffmloyd
Well-Known Member
darinray
Charter Member
1995 model you have.. And yes your machine is a 24V system.