Track fell off Komatsu D20p-7, any suggestions?

My left track slipped of the front idler and bottom rollers. Its still on the sprocket and top roller. Happened while traversing some rocks off camber. I was able to back it up to a flat area where it now sits

Any ideas on how I can get it back on? I tried to releave the pressure in track tensioner ram by removeing the gease filler zerk but nothing came out. Is there a fitting somwhere to releave the ram pressure? If I can releave the track tension maybe I can slip it back on? Probably invlove the purchase of a couple 10ton botle jacks...

Thanks.

Cut a block to fit between the blade and the track. You should be able to push the Idler back with the blade angle. Once its retracted you can pry the top of the track onto the idler and raise the front of the machine with the blade and you should be able to pull the track onto the bottom rollers.

If I remove that ram zerk will the grease come out if I push the idler with the blade? The first time I removed the zerk I rocked the dozer back and forth and no grease came out even with it under lots of tension. The track link channel is rideing on the inner lip of the bottom rollers making it very tight.

I seems to me that it should but there should be another relief valve somewhere too. The track may have your idler pushed sideways so hard that it wouldn't let it slide when you tried rocking it back and forth. Its been about 18 years since I delt with one of Komatsus smaller dozers.

relief

there should be a 7/8ths bolt head you loosen but dont take out this will release the pressure.at least on cats thats what there is.

Don't remove the zerk assembly all the way....just loosen it up about 1/2 a turn. If you remove it, you may lose the check ball at the bottom of the fitting when the ram comes back...(think that's where it is).
From your pic, the block and blade should move the idler back, as the idler is gonna be pushed to the inside a bit by the angle of the blade on the block...and if it's jammed, looks like it would be jammed to the outside.
Be careful, this stuff is unforgiving.
Good luck
Pete

IIRC to loosen the track you don't remove the zerk fitting, you loosen the "lubricator" that looks like a big nut or plug that the zerk fitting screws into. Don't back it out more than 1 turn though. The grease should come out of a relief cut into the side of the threads (again IIRC).

machineman, as others have indicated the larger fitting (not the little zerk) should be loosened one full turn ONLY. If you then apply pressure to the idler the old grease should be pushed out allowing the adjuster piston to retract.

If there appears to be a lot of tension on the idler and spring that can't be relieved you should check that the preloaded spring assembly hasn't failed. These can be quite dangerous so be very careful.

Good info... When I removed the cover the spring was in good shape. The nut that the zerk goes in looked like it was in another nut that threads into the cylinder. Might require 2 wrenches to prevent the looseing of the larger nut in the cylinder. Not sure what size they were. The hard part may be getting the dozer up high enough in that soft ground to slip the links back under the bottom rollers. The site is remote and I won't be back out there for a couple weeks so I want to be well prepared to fix it.

if it still won't relieve pressure you might try to find the master link in the track and take it loose. Make sure it's somewhere on the rear sprocket when you take it loose. this should relieve the sideways pressure and pressure in general, then maybe the idler will slide back. I've got lots of ideas......not guaranteeing any of 'em are good ones

It's possible you have a stuck or frozen track adjuster. That might explain why the track came off in the first place. If everything you try will not move that idler and adjuster fork back, that's most likely the problem. It will then require disassembly of the track and the adjuster hardware -- CAREFULLY. Once you have it apart, clean up and inspect the various parts, then replace what you have to and reuse the rest if undamaged. This is not an uncommon problem with smaller dozers.

Good Luck!

Update:

I was able to get the track back on. It wasn't hard and only takes an hour or so depending on how much dirt you need to chip out.

Procedure:
1. Remove ram cover and clean out dirt around Zerk. (17mm bolts)
2. Loosen 27mm nut that zerk goes into, lossen 3/4 turn only. (Grease should start coming out of slot in threaded ram cap)
3. Put wood block between blade and tracks. Use blade to force idler back. (more greease should come out)
4. About every 2min apply more pressure to the block pushig more grease out. You have to keep repeating this until the idler is back far enough to slip the track over the front idler.
5. Release block from blade and lift up front of dozer with blade.
6. Use pry bar to slip front track over idler.
7. Tighten the 27mm grease relief nut.
8. Usaully the track is off the bottom rollers as well so if possible winch or pry them back under the rollers. If this is not possible (as in my case), with the front end up, slowly rotate that track forward using the correct steering lever while the other track ramains stationary. This should ride the track back under the rollers. If you think the track to loose and will come off the front idler again pump some grease back into the ram. Try again to run it back uner the rollers.
9. After its back on, start filling the ram back up with grease. If it gets to hard to pump drive the dozer back and forth a few feet to relieve the strain.
10. Fill to correct track tension. Mfg spec is 20 to 30mm track droop.
11. Drive around and check tension again.
12. Put cover back on... DONE.

Good Job!

Machineman, how do you like that Komatsu d20?

Legdoc said:

Machineman, how do you like that Komatsu d20?

Click to expand...

Its a good machine. Being a small dozer it takes a few more passes to get the job done but for my needs and small budget it's worked out great. So far no major issues. Mine still has < 3000 hours. I use it on my property to to clear brush, make secondary roads, and grading. Cosmetically I've beat the hell out of it with dense brush breaking the lights and scratching the paint all up. Also its small size makes large rocky areas difficult to push through.

I know this has been on for sometime. Almost 8 years later the advice came in mighty handy. Thanks to all.