Section for komatsu d20,21 and similar grey market dozers

[oldhousehugger]

I'm not sure what you mean by "need to replace the clutches and the final drive was removed." Some further explanation would be helpful. I got my manual from an online source. It's been so long ago that I do not remember who it was. Look for the official bound shop repair manual. The PDF's are tedious to work with. The owners manual has little actual useful repair information.

I don't know how common the backhoe attachment is but manuals for that will be rare.

The steering clutches are located directly in front of the backhoe in the transmission weldment. To access them the backhoe will have to come off in order to work on them. The Main clutch is bolted to the engine and connected to the transmission by a short drive shaft. You will need to drain the wet clutch, unbolt it and lower it down so you can pull it out from underneath the machine.

To identify part numbers from schematics I use k-part (dot) com. Komatsu dealers are very cagey about who they let have information. These guys used to be free as well. Now its by subscription.

 

[Spkerking]

the steering Clutches are already out. The person I bought it from removed the final Drive think that was the problem. it was not but I will have to pull it back apart and inspect the bearing and replace the gasket on the housing. Do you know where the serial number plate is? I would like to confirm the model and find out what year this is. using the number on the transmission housing and exhaust manifold I came up with D20P-5 but I could not find a range of years.

 

[Back Track]

Hello! New member here. I've read through all 140 pages of this thread -- amazing how much great info everybody has contributed. I have not seen any information about the specific issue that I'm having, though, so here it is.
I've got a D21A-7 with 825 hours showing on the clock. I bought it in March '22 and have put about 30 hours on it. Everything works fine except over the course of those 30 hours it has developed a pretty serious squeal, but only when backing up. Going forward there's no un-ordinary noise. I used a mechanic's stethoscope and listened to the rollers and sprockets while it was up on blocks and was pretty convinced the noise is coming from the rear sprocket hub (on both sides - the right more pronounced than the left). The oil level in the final drives was basically full and looked clean, but I didn't know what weight or type it was, so I drained them both and refilled with 30wt according to the manual. I did find a small amount of metal shavings in the left drive when I changed the oil. I was told the machine had been recently serviced before it went up for sale. All the fluids looked full and clean and everything worked as it should.
Any ideas on why the tracks, etc. squeal (loudly) ONLY in reverse would be much appreciated.

 

[Krackerjack9]

find it odd that noise would be coming from final drive area, about a year ago I had a squeal but would only happen when I was making a left turn when pulling left steering lever, it turned out to be a big bearing on a arm that engades the steering clutches, and its a pain to change, your description and mine dont seem to match but odd that its in reverse and coming from both sides

 

[Krackerjack9]

the steering Clutches are already out. The person I bought it from removed the final Drive think that was the problem. it was not but I will have to pull it back apart and inspect the bearing and replace the gasket on the housing. Do you know where the serial number plate is? I would like to confirm the model and find out what year this is. using the number on the transmission housing and exhaust manifold I came up with D20P-5 but I could not find a range of years.

Serail number is stamped on the back of dozer that big plate between the final drivers on the drivers side i will have model number then serial number stamped on from top to bottom as far as year thats something I dont know there is Komatsu Guru that is in NY named Darin Mitchell he has all sorts of parts for these machines DM machinery or PM me and I send you his phone if you cant find on google search

 

[oldhousehugger]

Try pulling the cover off the brake adjuster nut at the back of the machine. If it's up on blocks you aught to be able to listen for the sound easily if it's coming from the brake/clutch area. A squeal could be from the brake band dragging on the clutch drum in reverse. There are 2 springs holding the brake band. One or both could somehow have come loose.

Also check to see if the sound could be coming from the front idler bearing.

Also check to see if there is something wedged in behind the drive sprocket rubbing and making the noise.

Also check to make sure the emergency brake lever isn't engaged. Ask me how I know.

 

[Back Track]

Thanks for the suggestions. I tried everything and was hopeful that maybe it was the emergency brake. I disconnected the linkage from the brake pedal just to make sure there was not any excessive pull on it - no change. I also listened to the two brake adjuster nuts and readjusted them according to the manual - even backing them off an extra half turn just in case they were over-tightened - no change. I also listened to the front idler bearings; there was a just bit of noise coming from them but nothing at all like that from the rear sprocket hubs. I'm not set up for (or capable of) tearing into the sprockets, so I'm probably going to have to take it to the equipment shop and pay the piper...

 

[g_man]

Did you try listening to the transmission case ??

gg

 

[Back Track]

Not specifically. Where would be the best place to do that?

 

[g_man]

Not sure - on my Dresser it would be under the floor boards. I'm thinking maybe the reverser shaft in the transmission but I hope not.

gg

 

[luckybull7]

guys, what is the meaning of these 3 light indicators?
Additionally, shouls i missing 2 fuses on this fuse box?

 

[IrondogKane]

guys, what is the meaning of these 3 light indicators?
Additionally, shouls i missing 2 fuses on this fuse box?

Not sure about the fuses, the light are from L to R charge lamp, oil pressure caution lamp and heater signal

 

[IrondogKane]

Great forum
Have a D21A-5 with hydro shift and have a question. The gear shift lever linkage came loose at the lever while operating. I got it reconnected (big pain in the butt) but afterwards it seems to be in constant 1st and no neutral except when the lever is in dead center. I am thinking that in the speed valve spool might have gotten pulled out a little to far and the 2 detent ball and springs might have gotten loose and are not allowing the spool to move forward enough. Anyone ever had this happen or thoughts on this would be greatly appreciated .

 

[Back Track]

Not sure - on my Dresser it would be under the floor boards. I'm thinking maybe the reverser shaft in the transmission but I hope not.

gg

Followup on my squealing in reverse issue... Turns out it was just the track pins. I hauled it into the local heavy equipment shop, expecting the worst. They said because it had sat for so much of its life (it's only got 800 hours on it...) the track pins had gotten somewhat frozen (rusted?) in and were complaining very loudly (but only in reverse). They soaked the tracks in waste oil for a couple of days and told me to go use it. It was a HUGE improvement. I'm continuing to squirt oil on the pins every now and then just to be sure they get completely loosened up, but I'm a happy camper now! Plus, the shop didn't even charge me a thing. They said "we really didn't do much of anything to it."

 

[Gardozer]

I have

Hi Steve

Thanks for the upgrade.
If anyone needs any book info on the D21, I got the books.
Pete

just bought a D21p6 this summer and now I’m having trouble with turning it. Do you still have the manual available thanks

 

[Gardozer]

I have a very similar problem with my d21p6 . I replaced the steering clutches last summer.Every thing was working perfectly until I started to use it this week. It worked great two weeks earlier. Now it turns to the left but when I try to turn to the right it does nothing, the engine does not seem to lug down. it is if the left track isn nor turning. I hane taken the seat floor board etc off, and it seems that all the visible linkages are the same left and right. any help or advice would be greatly appeciated.

Here is a picture of my D20A-6 dashboard. I don't know if you are talking about the same thing as what I have an arrow pointing to, which could very well be located elsewhere on your dashboard, but this is the display for the glowplugs to let you know they are working.

View attachment 93161

I have an owners manual and service manual for the D20 and D21 A and P version 6 machines. but not the version 7. I actually have an extra service manual that I am willing to sell for 20 bucks (the cost to have it copied) plus shipping. It is a copy of a copy, so there is a little reduction in the quality of the print and drawings, but still very readable.

Do you still have a copy of the manual available? I’m in Mt Enterprise and could pick it up. Thank You

 

[tool_king]

Do you still have a copy of the manual available? I’m in Mt Enterprise and could pick it up. Thank You

What is your email ?

 

[Gardozer]

Garwinthegreat@yahoo.com

 

[tool_king]

Garwinthegreat@yahoo.com

Email sent to you .

 

[jhamill01]

D21P-6 cold start problems

New to the group. Just purchased a D21P-6 yesterday. Injection pump was said to have just been gone over 10hrs ago. Problem is, will not start cold. Will smoke when cranking, but won’t fire. If you give it a small shot of starting fluid, it will fire, but then it has a raw fuel smoke to it for quite a while. Any help would be greatly appreciated