Track thrown

Yellow Machine · Post by **Yellow Machine** » Thu Nov 17, 2011 6:58 pm

Since I have put a loader on my 440ICD I have been throwing tracks. New bushings, pins and rear sprockets last winter. All of the idlers good no play as far as the bushings are concerned. The chains are quite worn but can not find better ones. I have weights on rear. I have been told that it is a worn front idler wheel causing the trouble. Does anyone have any thoughts on building up the front idlers or chains if it will fix the problem. If so does anyone have the specs for the chain and idler.

Tigerhaze · Post by **Tigerhaze** » Thu Nov 17, 2011 7:26 pm

I would suggest additional assessment of the reason for the track derailing before you attempt to build up the front idlers, which involve considerable effort on someone's part.

Loaders seem to cause more problems with throwing tracks because the center of gravity changes when lifting or extending the bucket- this can lift the track off the ground momentarily on uneven ground and then cause a slightly loose track or misaligned track to become derailed. Similarly, sharp turns with worn undercarriage components and/or loose track can also cause derailment. Travelling parallel to a slope or incline can cause the downhill track to slip off the bottom rollers. Don't ask me how I know all of this

I would first ask you if the tracks are properly tensioned. There is a small amount of sag around the top idler when properly tensioned but not excessive- there are measurements for it in the operator manual (at least for 2010s). I think for my 2010 the allowable sag is a couple of inches. Loose tracks are a big reason for derailment, especially if some undercarriage components are worn.

Assuming the tracks are properly tensioned, I would next check alignment when in motion. The best way is to have someone drive it forward and reverse for enough distance to get a couple of track rotations- while in motion walk slightly to the side in front and behind to look for the rails moving to one side of the undercarriage components. Watch the front idlers to see if they are out of alignment or wobbling- it may simply mean you need to adjust, tighten, or shim the front idler brackets or idlers. Also watch the top idler and bottom rollers- if the top idler flange is really worn it doesn't take much for the track to slip off. If the bottom rollers are excessively worn, they may be hitting the pin bosses. Newer rollers with worn rails can cause problems because with the rolling ssurface of the roller being unworn, there is less height distance between the rail and top of roller flange and it doesn't take much to jump the roller flanges when going over uneven terrain. Also check when turning- this is when some track jumping issues manifest themselves.

I wouldn't expect some of the usual causes such as track snaking and chains riding up the teeth of the sprockets have likely been eliminated on your machine with the new pins/bushings and sprockets. I am also assuming that you checked the sprockets for play- worn final drive bearings can cause the sprockets to lean inward or outward causing alignment and jumping problems.

Finally if a track frame is bent it can cause alignment issues at the front or rear.

Let us know what you see-it may very well be the front idler flange height but good to see where and when the jumping is happening. There are specs for rail height available but I didn't see specs for your crawler on the CrawlerHeaven site. I am not sure I know of specs for front idlers and you may have to find someone with a new front idler to measure for you- the issue may be not only flange height but also width.

Yellow Machine · Post by **Yellow Machine** » Thu Nov 17, 2011 8:01 pm

Thanks for your info. It derailed under a full load. I tightened the tracks to spec from manual with rail above upper idler. My friend machined a new upper idler to specs from the manual. The bottom rollers are hitting the pin bosses but I was thinking this was because of the worn rails. I checked the site for rail heights but could not find a height for a 440. do you know if they are the same as one of the other models. I do believe they are quite worn though. I will also check the bottom rollers to the specs in the manual. We did check for any wobble when I did all the track work. I do remember the rear sprockets turned perfectly true when we had the track off. As close as I could see the track frame is straight. I will try to find the idler specs for height and width as the same friend said he has a rotery welder he could build them up with.

Gil · Post by **Gil** » Thu Nov 17, 2011 9:19 pm

The JD440 rails / chain links have an original height of 3.19". If they are 3.00" or less, they are considered 100% worn according to Deere (or according to me considered about what I can expect to find on my machines).

I have a NOS roller somewhere if no one else has the dimensions. It would be after Thanksgiving before I could locate it, if you need me to measure it. GLP

Yellow Machine · Post by **Yellow Machine** » Thu Nov 17, 2011 9:25 pm

Thanks. I will check my rail height but am sure it is way less than 3". Is the roller you are talking about the front one?

Tigerhaze · Post by **Tigerhaze** » Thu Nov 17, 2011 9:35 pm

i think Gil is talking about a bottom roller, as the front one is called a front idler.

You didn't mention if you have 2 bolt or 4 bolt rails, but generally rails are the same for the 420s, 430s, and 440s. Rollers are same for 420s, 430s, and 440s, and also may be the same for 1010s and late S/N 40s. I'm assuming you didn't have them replaced at some point with 350 rails.

One of our members put together a nice cross-reference chart for undercarriage- it can be found here:

http://users.upwardaccess.com/trachte/c ... geXref.jpg

Since you mentioned the track jumped while loaded, I tend to think that it occured while rear of track lifted slightly off the ground coupled with maybe a turn. This allows the track to derail off the bottom rollers and if not caught quickly enough, causes the track to come off. I am guessing this based on my experiences.

The pin boss wear can be a combination of both rail wear and roller surface wear (the roller surfaces shrink in diamater as they wear as well as the rail height wear which allows the roller flanges to touch the pin bosses). however I wouldn't think that alone would be causing the track to jump unless a flange is broken off or roller is flat spotted. however you mentioned you inspected it.

Sorry can't be more help-others may have ideas.

Yellow Machine · Post by **Yellow Machine** » Thu Nov 17, 2011 9:53 pm

Thanks Tigerhaze. I am not sure what you mean bt 2 or 4 bolt but if you are talking about the pad bolt pattern it is 4. You were dead on about load and turning it was just after a backup then going forward. I do know no roller had any broken flanges but what do you mean about flat spot? I thought that was Gil was talking about but hoped for it to be a front idler. Do you think it would help to add more weight to the rear? At this time I have about 600 lbs. I will check both the rails and rollers for just how much wear there is and you have been quite helpful with your ideas.

JD440ICD2006 · Post by **JD440ICD2006** » Fri Nov 18, 2011 7:30 am

What type of grousers are on your 440ICD? It is highly recommended to only have the semi grousers on when using a loader. The regular grousers with deeper bars will not allow the tracks to slide when loaded. This not only can cause a track to jump, but quickly wears out parts of the U/C.

JimAnderson · Post by **JimAnderson** » Fri Nov 18, 2011 7:34 am

I posted the dimensions for bottom rollers and front idlers on
February,25,09,These were based on new Deere 40-1010 bottom
rollers and new 440 front idlers.Just type in bottom rollers and do
a search by author and its on here.Hope this helps.Luck JimAnderson

Post by **Lavoy** » Fri Nov 18, 2011 8:07 am

You should have about another 500lbs on the rear, that might help.
I have a couple of NOS front idlers with new bushings if you decide you want idlers.
Something is wrong, we just need to figure out what it is.
Lavoy

Tigerhaze · Post by **Tigerhaze** » Fri Nov 18, 2011 10:02 am

Yellow Machine wrote: I do know no roller had any broken flanges but what do you mean about flat spot?

Flat spotting is when there is uneven wear on the roller wearing surface because the roller stops turning and instead slides along the rail surface, causing a flat spot. If the roller then starts turning later, it causes an uneven surface which would cause the track to jump. I don't think that is your issue because you mentioned you had checked all of your idlers and rollers for bearing wear.

Lavoy's suggestion on counterweights may really help your situation. Less counterweight than recommended may cause you to tip forward with a full bucket and pick the rear of the crawler off the ground, especially on uneven ground- that doesn't help keeping the tracks aligned with the bottom rollers, especially if the tracks are a little loose.

Yellow Machine · Post by **Yellow Machine** » Fri Nov 18, 2011 4:55 pm

Thanks everyone. The grousers are only about 1/2 to 3/4" high. I will check your post Jim to check out my parts and add extra weight to the counter balance. After checking mine if they are the problem I will be in touch Lavoy.
Ted

Yellow Machine · Post by **Yellow Machine** » Fri Nov 25, 2011 5:16 pm

I am adding some additional info to my previous post. Since I am new to all this and this is a new machine to me any suggestions to my derailing problem would be appreciated. The derailing before and now has only happened on the right side so far and always with a loaded bucket of a 831 loader.
Left front idler is 18 15/16", flange height 3/4" & width of 1 1/2".
Right front idler is 19 1/8", flange height 5/8" & width of 1 1/2".
I was only able to measure the back rollers on each side and both are 6 7/8" & a width of 4 1/2" between the vertical flanges.
Grousers are 5/8' tall.
Rail height on both sides is a consistant 2 15/16"with some pin boss wear.
The track carrier is straight on the outside so I guess it would be the same on the inside.
All the bottom rollers look the same as far as wear with no flat spots or broken flanges all of them turn freely.
I am going to add the extra counter weight as suggested by Lavoy.
The machine is going to be brought in, tracks split and rails built up with weld. I am also going to look at a 440IC loader and bepending on cost and condition as a parts machine.

Post by **Lavoy** » Fri Nov 25, 2011 5:28 pm

Do you mean you have new pins and bushings in the rails?
Grousers will tend to de-rail worse than street pads.
Lavoy

Yellow Machine · Post by **Yellow Machine** » Fri Nov 25, 2011 9:29 pm

What my friend did was make all new pins and rotated and built up the bushings in some cases as nessary. He had all the pins harden at his work.
Lavoy, how bad do you think the front idlers are and should I be talking to you about those NOS ones you have?

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