Section for komatsu d20,21 and similar grey market dozers

[Tim Ready]

First time poster. My D20A-6 "Squalls" when I tilt the blade left, but does not do that any other direction. Could that be a restriction somewhere, wrong Hydraulic Fluid (oil) in it, or? I also wanted to thank everyone for the wealth of information they have contributed here. Took me 4 days to get thru all 118 pages and I was so involved in it that I was disappointed when I got to the end. Special thanks to Larry as he is the one that inspired me to get a D20A in the first place!!

 

[tantoy]

Thats normal for tilt cyc. .not much volume in that cyc.

 

[Tim Ready]

Any places to find battery hold down hardware? Already talked to Kent Baugh (and he does not have).

 

[GuglioLS]

Consider 1/4" or 5/16" threaded rod from a box store. Bend a hook at one end, then cut to correct length. If the hold down hardware on your D20 is like mine there is a ~ 3/4" angle iron the length of both batteries with holes on each end held down by long rods at a ~ 45* angle with a small hook.

 

[Krackerjack9]

Any ideas?

trashed in as the sprocket wobbles on the shaft but the shaft is all good as in moving but the splines are bad and the sprocket is bad, if so I would just weld the sprocket to the shaft nice and square as possible then cut out the sprocket from the circles then get you sprocket ring and weld that in and your good to go

 

[epirbalex]

trashed in as the sprocket wobbles on the shaft but the shaft is all good as in moving but the splines are bad and the sprocket is bad, if so I would just weld the sprocket to the shaft nice and square as possible then cut out the sprocket from the circles then get you sprocket ring and weld that in and your good to goView attachment 192187 View attachment 192187 View attachment 192188

Not a good idea to weld a sproket to a shaft , weld will probably fail limiting later repair work . See if a new splin can be cut slightly smaller , have a matching spline cut on same thickness material to match it wide enough to clear the bolted cap , cut out used sproket to match new bit . Then carry on with fitting new rim normal way . Otherwise find a shaft and matching sporket off a wrecked dozer .

 

[Krackerjack9]

If your welder is good then it should fail or crack or what ever there is a shaft on ebay for 795

https://www.ebay.com/itm/NEW-A-M-KO...L-DRIVE-AXLE-SHAFT-10G-27-21311-/221261596944

 

[Krackerjack9]

the weld should not fail or crack, they weld 48 in pipe together on this massive pipeline their building now thur Texas along hy 44 and FM 624 and pick it up with excuvators and drop down the trench 10ft looking at it one would think that the pipe would bend or break but it dont

 

[epirbalex]

the weld should not fail or crack, they weld 48 in pipe together on this massive pipeline their building now thur Texas along hy 44 and FM 624 and pick it up with excuvators and drop down the trench 10ft looking at it one would think that the pipe would bend or break but it dont

Not a good comparison , if the sprocket could be veed out so every bit of the length of the spline could be welded it may have a chance to hold , seals are very close to the heat . Short cut too far for me .

 

[GuglioLS]

Looks like quite an invested in a new set of tracks and sprockets, why not fix it all the way? Nothing like repairing it properly. Be prepared to install new bearings and a seal or two. Tracks and sockets will be off anyway why not go for it?

 

[Joe C.]

Thanks guys for the input. I supposedly have a shaft on the way from Japan. Used for around $700. Also have a sprocket and seals coming. The worst part of it all is the sprocket and shaft are in excellent shape other than the splines. The old guy I bought it from must have had no idea what was happening as he really ate up the splines. I considered welding them only because I couldn't find a shaft anywhere. My problem was how do you get it hot enough to get a good weld and not burn up the seals behind the sprocket? And the shaft on ebay isn't the shaft for my dozer...

 

[Krackerjack9]

the seals are good dosnt leak at all, I had a leak in hose on the blade put 2 new hoses on and no leaks now, around the cylinders theres a seap but its just enough to attract dust and dirt but that's it, the rollers at least aonther 8mm before their worn enough to replace so if I get aonther 500 to 750hrs out of them then its ok with me. im just getting the out rims cut out and the new ones welded in, This was common practice up till the early 80s but Komatsu didn't start doing this till the 90s. And to get the sprockets pressed off you got have a better than average press. oh im sure you could hit it with a 15lb sledge and work it off but welding it has been done for years as standard repair

 

[Joe C.]

Got my shaft, new sprocket, and seals from DM Machinery, LLC. Got it all back together and it's doing great....except it won't turn right. Ugh. I feel a clutch job coming up. Would you do both sides even though the left side still clutches?

By the way, Darin is the man for hard to find parts on these little komatsu dozers. Thanks tantoy for mentioning him.

 

[mcbike57]

New member here. I recently purchased a Komatsu D21A-6. Was told it needs steering clutches. Shows about 2400 hours. Undercarriage looks great. Literally no wear on bushings and sprockets look almost new. Engine sounds good. Dipstick under the brake pedal shows clean/clear and full. Dipstick under the front of the seat shows clean/clear and low. Tank on right side shows no oil in level glass. There is oil leaking from the blade control shafts on top of the control bodies. All cylinders do not leak. Read into the posts for abit and then jumped forward. In the early posts I saw mention of 60 something men getting their first dozer. That's me now 12 years later than those early posts. The answer to my question/s may be in the many posts here already, but I will ask anyway. Here is what I would like to ask: How do I determine that the steering clutches are actually bad? The dozer goes back and forth just fine. From my little bit of research in the shop manual I downloaded the steering clutches are just a bigger version of a motorcycle disc type clutch and are under spring tension. The whole clutch pack is bolted to the final drive gear on one side and bolted to the output shaft from the differential on the other. Steering is initiated by pulling one of the steering levers which operates a hydraulic slave cylinder of sorts that compresses the springs in the clutch pack releasing the spring pressure on the pack which in turn disconnects the final drive gear from the differential thus letting the other track pull the dozer into a turn. Since the little feller goes back and forth easily (under no load just moving itself) is it possible that the steering clutches are stuck rather than worn out? I own and operate a small motorcycle business here in south central Kentucky so sometimes I understand how something works. Would rather try gathering information and checking all adjustments before actually taking it apart for no good reason. Also I am getting a little bit work brittle here of late

 

[mcbike57]

Me again. I really like that HEF has this section for us guys that buy these little machines to work around on our property. Thank you.

 

[mcbike57]

Me again. I do need a few pieces for this little dozer. The panel that goes on the right side under the blade controls is missing. The armrests are just two pieces of metal now. There is a front panel missing on the left side down below the throttle and gear shift and the lower panel behind the batteries is missing. These two panels I can fab easily enough, but the one under the blade controls would be a little tricky unless I could get a template to cut one from. Thanks for any and all help/advice.

 

[darinray]

Welcome to the forum.. Yeah there is a pile of pages in this section and I can remember when it was started. Well barely but still.. WOW times flying.. If the steering clutches are not releasing when trying to turn it will bog the engine down IF the brake bands are functioning properly too. If they are slipping for some reason then the tracks will stall out (not turn) when pulling a lever or putting machine under a load.. Will need more details on what its doing..

 

[mcbike57]

Welcome to the forum.. Yeah there is a pile of pages in this section and I can remember when it was started. Well barely but still.. WOW times flying.. If the steering clutches are not releasing when trying to turn it will bog the engine down IF the brake bands are functioning properly too. If they are slipping for some reason then the tracks will stall out (not turn) when pulling a lever or putting machine under a load.. Will need more details on what its doing..

I actually have not been on this little dozer since I bought it a week ago plus a day or two. At this time I have not checked all the adjustment parameters for clutch/inching clutch, steering levers and brakes. I can tell you that the day it was loaded for transport was warm and wet. The following day (day delivered) was cold and dry (30 degrees). gear shift cable was frozen and dozer would not start by key switch. Finally managed to get it started. Would not move. After it ran for a few minutes it began to move. Managed to move the gearshift just little. most likely just enough to semi engage first gear. Only way to change direction was to use the clutch/inching pedal which caused it to twitch a little to one side or the other. Pulling back on the steering levers made no difference what so ever. The weather has warmed up some here so I intend to check adjustments first, top up fluids, investigate the leaks on the blade control shafts, fire the little feller up and try to get it toward a big stump I have on the property and put it under a load to see if the clutches will slip Appreciate the reply. Thank You.

 

[darinray]

Keep us posted. I had one machine here that had the same symptoms and was actually ONLY the darn inching valve linkage was froze up not allowing the transmssion to fully engage. Take the floor board off and make sure the linkages are all moving as expected. Good luck

 

[mcbike57]

Thank You!