440IC Dealing with broken link?

[NEpilot]

Take it easy on me, my first post after reading for hours and hours.

New owner of a 58 JD 440IC that my wife has named YellowThunder58, she calls it yet another money pit (like motorcycles and racecars). Like all things in life if you get a "good deal" something is wrong or maybe many things are wrong. In my case this 440 had steering problems that with reading this forum and a copy of the service manual I was able to rectify without much drama. Machine runs like a champ and the bucket works with no leaks!

Fast forward to dealing with the undercarriage, one side had obviously been apart and would not hold tension and just puke grease out the tensioner. It was missing the ball-bearing, with that addressed and tension set I measured 23.40 --> 23.45" which seems to be in the 75% window I read about on here, so far, so good.

It is at this point I notice something more concerning that I missed previously, a damn broken outside link. It is broken where I would expect, at the point it kind of ramps down.

Now for the question; how on earth do I go about addressing this issue? I have found the master pin so I can take the tracks off without much drama but then what? I'm thinking this isn't the kind of thing I can just weld back together so I need some opinions. I am of the motto that if it is worth doing it is worth doing right but my budget has limits like most.

Thanks!
-Chris

[JimAnderson]

Hello Chris,
You have a few options to address the broken link.You can Vee it
out and weld it up with something like 7018 rod.A little grinding and
you should be good to go.You may be able to get a replacement NOS
link but then you have to match the worn height of the existing rails.
You could go with a worn used link but it needs to be close to the sizes of the worn parts and then to replace the link you need access to a track press.If it were mine I'd weld it and see how it holds up.IMHO it would be
be the easiest solution and you could always replace the link at a later
date.Luck, JimAnderson.

[pop pop]

weld it , make it look good.

[NEpilot]

I will take a picture in the morning, it was obviously used with the thing broken so it opened up a bit. Figure I will let the tension out and measure pin-to-pin on another link so I know what to make the final dimension as I don't know how much it has opened vs. wear.

With everything I've read about how hard the link base metal is I wan't even going to try to weld to it, but, with new optimism I will try!


Pop Pop - Didn't know there were any crawlers in Chandler! I'm there lots for business and every time more fields are gone and turned into more strip malls! That strange partially completed building with just the concrete floors near Price stays while new stuff all around it, just crazy!

-CC

[NEpilot]

Couple photos of the problem.

[hydrogeo]

Tough to tell from the pictures but it looks like the bottom of the link is bent a fair bit. If it were mine I'd be inclined to break the track so the link is on the floor and easy to work from all sides, and put some heat to the link and try and square it up as best as possible before trying to weld it. Not sure how the links are tempered, though. At any rate, a repair seems at least worth a shot. What does the link height measure?

[NEpilot]

Right side (side with broken link) track height = 2.955"
Left side track height = 3.021"

[vtjoe]

I agree with hydrogeo about putting the track on the floor, it would make it easier to access all sides. quality grinding before welding is the key. v it out so there a good 1/8 gap after you heat and realign it if you must by heating and bending, or not! the idea is to have about 30-45 degree open vee with 1/8 spacing and maybe about 1/4 inch undisturbed metal left in the center. vee from both sides is the best but not necessary. use 6010 or 6011 maybe 6013 for the first weld pass, to fill in the open space then fill out correct size with 7018 or 7014 grinding to completely clean between passes no slag or pit holes remaining a wire feed welder makes it easy
gas covered E70 RS not flux core you will get a lot of life out of it, post another picture when done

[hydrogeo]

New link height referenced in this post is 3.2"

http://www.jdcrawlers.com/messageboard/ ... .php?t=984

I'd weld it and give it a shot. Worse comes to worse you are going to have to split the track anyway to either replace the link or put a new set of rails on so at least it will go easy the second time.

I've found truth in the notion that owning a dozer is a lot like having kids, if one truly understood the work, frustration, and expense before hand there is no way you'd have either, but once you have them it's about impossible to think about not having them.

[JimAnderson]

If these rails are used on a loader you may want to start looking for a
replacement set of rails if you plan to use the machine a lot.If the
part of the rail that the pads bolt to is thicker then what the roller runs
on then expect more breaks.The 3.200 dimension on new rails is
from the pad mount to the rail section that the roller touches.As the
rails wear they also get thinner where the roller flange touches their
sides.The more wear the less structure is left to support the loaded
weight and you see more sag between the the pins.
From the pictures I'd say the break can be repairedbut I really don't
think there is a whole lot of life left in the rails.JMHO,Luck,JimAnderson

[NEpilot]

Thanks for all the suggestions and info, I'm going to attempt the repair tomorrow. I'll post some photos of the repair as I go, even if I screw it up at least there will be photos of what not to do.

It is 10 degrees outside so with some luck it will start in the morning!

[NEpilot]

I hope everyone doesn't mind lots of photos, if so just let me know.

After getting the old girl in the garage this morning it became apparent that taking the track off would be the best approach. Removing the track was a two beer task and some left over Chinese food from last night.


I'm guessing this isn't standard John Deere issued master pin with custom c-clip.


Actually doesn't look that bad, but it was loose and came out with just a couple hits.


Max snake -


Hmm a second strange looking pin -


Other side of second master pin?


The reason I took the track off in the first place, the cracked link. Appears to me that maybe the reason it broke was a seized pin that ended up breaking the bushing. Now what?




Drive sprocket -




Front wheel -


Tensioner / Spring -



This was why I didn't want to take the track off, I had a bad feeling I would find more things wrong. The top idler has a decent flat spot, but I got it to rotate nice.

Front most bottom roller is trashed, I doubt there is a bearing left inside it so that has to come out. Three in the middle are a little sloppy but reasonable , the first roller is a sealed type unit that has almost no slop.

Now the big question, what to do about that broken link? Sure I could weld it but do I also weld up the broken bushing? Or it this a loss and time to start shopping for new rails?

[gus]

From the photos, I'd be looking for another set of tracks. There's too much wrong there. I paid $500 for a half worn out set that had the pins turned in far better condition than yours. Fix it once.
Gus

[JimAnderson]

I agree with Gus,those rails should be replaced.With that said I would
repair the link and put some hours on the machine.Nothing but use
will show additional problems faster.A 440 with a loader is a lot heavier
than one with a dozer setup.Decent used two bolt rails are not that
plentiful but you can get 350 rails and pads new.Down side to that
solution is having to rerim the sprockets.Luck,JimAnderson

[NEpilot]

Not sure what the loader weighs (it is a Deere 91), but I discovered without the rear weights the dozer likes to tip forward with even an empty bucket!

The rails where the master pin is located seem to be of a different vintage, the pads on that section are bolted using square nuts Vs. hex nuts for everything else. The PO also seems to have used a grossly wrong size pin for a second master pin so that needs to get addressed.

I started cleaning up the broken link / bushing this afternoon trying to get a game plan. Going to v-groove it and try to weld using my mig and some L-56. Trying to work out how to weld the bushing back together without welding it to the pin by accident.

I'm going to have to deal with the front most roller but first I need to cut three of the stuck nuts holding the rock guards. I got all but three and the three that are stuck I ripped the inner head trying to break the nuts loose, just one more thing to fix

The upside to all this is how mechanically simple the thing is, technology just like an old Cessna or Cherokee.


Is Lavoy the person to get a new master pin / clip from?

-Chris