thrown track

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77 Ford
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thrown track

Post by 77 Ford » Sat Jan 07, 2012 5:30 pm

I've trying to search and find some threads on getting a thrown track back on but i cannot find them. Does anyone know of any of the top of their heads?

I was driving and hard a loud pop from the right side and the track was off. It didnt seem very loose to me but I had not actually ran the track measurement.

I took the plug out of the adjuster and got about 1.5" or so out of it shoving it back, is that enough?

Im heading back out tomorrow with a couple of jacks to get the whole right side up.

Any tips or tricks would be greatly appreciated.

PS On another note I think resealing the water pump backing plate has fixed my water leak.
JD- 450C track loader
Serial #208336T

Finnsawyer
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Post by Finnsawyer » Sat Jan 07, 2012 10:48 pm

I had a track thrown last year and found I couldn't back off the mechanical adjuster. I cut down a 10 inch maple tree and cut a section off that I placed against the blade. I then used a screw jack off it against the track at the front idler to compress the track spring. Warning! The idler will turn somewhat as the spring is compressed. You also will need to use a wedge or some means to hold the spring in a compressed state. It may take several tries because of that idler rotation to get enough compression. Then you bar the track back on. It's really a two man job. :(

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Post by KenP » Sun Jan 08, 2012 4:51 am

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Last edited by KenP on Fri May 31, 2013 4:55 pm, edited 1 time in total.
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LeonardL
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Post by LeonardL » Sun Jan 08, 2012 4:16 pm

I agree with Ken!! These springs are a force to be reckoned with!!! :!: :shock: Have you tried to free up your adjuster by using the blade to help shove it back. If your idler is trying to roll, a good trick to try is placing a good hard wood block standing vertical against the front of the idler. This block needs to be taller than the center line of the idler.
Then place the horizontal block against the vertical block directly in line with the center of the idler and against the back of your blade. Then open your adjuster screw and depending on what adjuster you have, remove the grease fitting as well. Use your blade under power to help push the adjuster back and break it loose.
Wear safety glasses and gloves because I have seen the grease escape very rapidly and it can go in all directions at a high rate of speed.
If it doesn't release, smack the ram, not the cylinder with a hammer a couple of times and see if you can jar it loose. I have even used a big pipe wrench on the back portion of the ram and turned it under pressure and they will break loose.
I have also used a high pressure grease gun and forced the ram out just a little to break them loose.
What ever you need to do... You need to repair the problem. It will only help you later on.
Ken is exactly correct. Shoving the shock spring back isn't the right way to do this. It's a good way to get hurt and ruin your spring in the process.
Fix the problem! Don't give it a lick and promise because you might just get hurt. We don't want anyone getting hurt. I've seen these springs break and the end result wasn't a pretty one.
And that is my several cents worth...
40 plus years working on JD 350s, 400Gs, 450s and other equipment both Ag and Construction.

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77 Ford
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Post by 77 Ford » Sun Jan 08, 2012 8:42 pm

Thanks for the replies.

I went out this morning and was able to get the track back on in about 45 mins. I picked up the front with the loader bucket and jacked up the back with a 8 ton bottle jack. I had the whole right side about 4 inches off the ground. I then was able to use a come a long hooked to the bucket to pull the slack forward and a good crowbar to pop it over the idle pulley. Started pumping grease and pushed it out, text book style.

Now I need to figure out if I have something wrong or was it just an accident the track popped off. I actually broke out a straight edge and my tape and the left track was near 1.75" sag, spec is 7/8 to 1 1/8. I don't know what the right track was but they were both pretty close. They are now both set to 1".

I checked all the bottom rollers they seem tight, the sprockets and idler all seem good. The chain is between 25% and 50% wear according to crawler heaven's spec sheets. The adjuster on the right side is original the left side has been replaced with an after market.

Is there any chance this was a freak accident? I was in very rocky ground when it popped off. Would having an extra 3/4" of track sag be too much?

I took some pictures of the under carriage and I'll try and get them posted up soon in the picture section.

But at least it's not leaking water!
JD- 450C track loader
Serial #208336T

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jtrichard
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Post by jtrichard » Sun Jan 08, 2012 9:34 pm

yes if the track is lose it will come off thats why they are adjustable...... :lol:
2010 with 622 dozer with mod. 35 ripper and a 2010 with 622 dozer bought in 1969 and a 2010 loader with drott and mod. 36 ripper

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77 Ford
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Post by 77 Ford » Mon Jan 09, 2012 8:15 am

Is 3/4" to 1" of extra sag loose enough for it to come off ?

I started some pictures over in the show and tell section:

http://www.jdcrawlers.com/messageboard/ ... 4475#34475

Thank you again for all the help.
JD- 450C track loader
Serial #208336T

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CatD8RII
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Post by CatD8RII » Mon Jan 09, 2012 6:21 pm

From what I can make out on the picture, the recoil spring looks like it is a little tired. It should have one nice even pattern, like any other spring. If you look in the middle of yours, the coils are spread out, and they're all bunched up at the ends. If the recoil can't expand properly it can't "hold" the idler in position. Then when it's compressed and then "sticks" it could result in a "slipped" track. When new from Deere, the springs have covers over them, this helps (isn't 100%) keep dirt away from packing around the spring.
Also, you mentioned you were working on rocky ground. I'm not 100% on 450s, but the 350's came with rock gaurds standard. They try to keep rocks from getting between the rollers and chains.

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LeonardL
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Post by LeonardL » Mon Jan 09, 2012 10:35 pm

I agree with catd8rll on this. Your track is worn but not to the point of being the real issue. At least not now. I agree with catd8rll on the spring as well. It looks collapsed to me. Or, someone has set the tension wrong on it. It may even be broken.
The other issue of the rock guards... If you are in rocky ground, you have a lot of space between to back of the idler and your front lower roller. Your track tension looks okay with it sitting where you have it in the picture. But given the terrain you are working in, I'd say you have run a rock between the track rail and the front idler. Thus causing the track to roll off. Sometimes it doesn't take much. They like to do it when you back up and turn.... As they say... Been there... Done that!
I would clean those springs up and inspect them. I think they have an inner spring as well, just like the 350s. If that spring is broken it will cause the larger one to collapse. I really don't see a given issue with your under carriage. Other than it is getting worn. It is definitely past the 60% point.
40 plus years working on JD 350s, 400Gs, 450s and other equipment both Ag and Construction.

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77 Ford
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Post by 77 Ford » Tue Jan 10, 2012 8:11 am

Thanks for the suggestions, I'll try and get a good look at those springs next time I'm out there. There is an inner spring on the 450'c as well. Looking on a few sites that sell after market parts most only show the outter spring, is the inner harder to get?

Looking at the part numbers it appears the early serial number 450c's had the two spring configuration but the later ones had a single spring. The caps on either side of the spring use the same part number so is it as simple as buying the newer single spring and dropping it in?

I'll also have to look and see if the mounting holes are there for the rock guards and considering trying to run them down if so.
JD- 450C track loader
Serial #208336T

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77 Ford
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Post by 77 Ford » Tue Jan 10, 2012 1:17 pm

Upon doing more research I'm still a little confused and I called JD and while they did agree with me they did not instil much confidence.

It appears if you have serial number less than 222447 stock was two springs

T32048 & T20872

Serial numbers after that had a single spring of T106882 and a "tube" T10550 that basically replaced the inner spring. When looking at the spring rates the single out side is about 5200 lbs/in and the double has 900lbs/in on the inner and 3,400 lbs/in on the out side.

Both out side springs have the pretty close to the same dimensions.

Again it appears you can change to a single spring if you buy the tube but it sure would be nice if someone could confirm that before I pulled the trigger on it.
JD- 450C track loader
Serial #208336T

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Tigerhaze
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Post by Tigerhaze » Tue Jan 10, 2012 1:39 pm

77 Ford wrote:Is 3/4" to 1" of extra sag loose enough for it to come off ?

I started some pictures over in the show and tell section:

http://www.jdcrawlers.com/messageboard/ ... 4475#34475

Thank you again for all the help.
An inch of extra sag is enough to throw them- oftentimes it happens when you are running parallel to a slope (the downhill side will derail) or on a sharp turn going down or up a hill. Proper tension (meaning a little slack per operator's manual) is important to minimize this from happening.

However once track gets worn it can be inevitable if doing a lot of turning or working on slopes. After a while you get to noticing very distinct noises when the track just starts to slip and you can stop before it fully derails.

I think you may have been looking for the thread I posted which had photos of attaching a slipped track:

http://www.jdcrawlers.com/messageboard/ ... ht=slipped

Sorry I didn't get to you sooner.
(1) JD Straight 450 crawler dozer with manual outside blade; (2) JD 2010 diesel crawler loaders; (1) JD 2010 diesel dozer with hydraulic 6-way blade; (2) Model 50 backhoe attachments, misc. other construction equipment

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digitup2
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Post by digitup2 » Tue Jan 10, 2012 5:58 pm

If you are coming off on the front idler then the idler is probably wore out the track should be kept tighter as your track life diminishes.Only two places the track will pop off and the other is at the back sprocket what also happens is the rail gets off set in the rollers and as the chain rolls forward the back sprocket will pick the chain and kick out under or as you are in reverse and the roller flanges pop over the chain then the chain will kick over the front idler and roll out .As the crawler gets older keep the chain a small bit tighter.Digitup.

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77 Ford
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Post by 77 Ford » Fri Jan 13, 2012 2:47 pm

I called a 2nd JD dealer and he agrees with me and the first dealer. I should just be able to buy the single bigger spring from the later model serial numbers and slide it in. He thinks the tube is merely a safety tube for if the spring breaks it can't fly out.

I'm going to try a replacement and see how it goes.
JD- 450C track loader
Serial #208336T

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77 Ford
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Post by 77 Ford » Sun Jan 15, 2012 9:27 pm

FYI you guys were right on track ( what a pun....). I went out this weekend and looked at my springs very closely. The one you see in the picture is the good one....it's only broke in 2 places. The other one is broke in 5 places, it's amazing it works at all.

I used it about an hour being extra careful and did not have any trouble. Of course the tracks are tighter too, probably a combination of both.
JD- 450C track loader
Serial #208336T

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