I was doing some light dozing yesterday on my D4D and noticed my left track starting to come off. I caught it before it completely came off the front idler and it was already off the lower rollers. I backed up and managed to get the track re-seated. Did a quick check, everything looked OK, track tension looked about factory, so kept going. At the end of the day I was doing a slight turn, getting ready to shut her down, and the track came off all the lower rollers. It's still on the drive and idler sprocket. The pins, bushings, rollers, etc. are darn near new. I don't think I can move the dozer without tearing stuff up. Is there some trick to getting the track back on or do I need to go get a jack big enough to lift the dozer and just move the track back under it? I guess I'm just trying to avoid driving to town and spending the money. Any ideas what's causing the track to come off?
You might look at the frames wear the idler rides. They might need some welding. You might try shimming your idler to take some slop out. Make sure your bearings are good in your idlers. You don't need a jack to lift your dozer. Put blocks under the rear of the machine then push your blade down. This will lift your machine up. Good Luck.
sometimes what I do is put your blade all the way down so you get the FUBAR track off the ground as far as possible then stick it in reverse and only turn the FUBAR'd track slowly (by taking as much wieght off the tracks as you can with the blade down it should want to spin out in reverse when your just trying to turn one track). Now this only works under certain conditions depending on what way the track is coming off. Show us some pictures
i have the same problem but my pins are pretty worn. is theis a dry undercarriage or a salt undercarriage. the problem i have is on slight slopes going across the slope, the rails are rounded on the outside and the rollers are rounded on the outside flange. makes it want to roll off the rollers before it tries to come off the idler. loosen the track before you try to put it back on and then tighten the track tighter than you had it and try again. the pins and bushings may be worn more than you realize. when you have it loose, pry between the pads to check the wear.
If the lower rail guards are missing that will also tend to encourage the tracks to walk off.
OK, got the track back on using Turbo's method. thanks! Worked like a charm. I went to tighten the track and noticed the spring is broken. Yet another thing the PO didn't tell me about. I guess that explains why he had the tracks so tight when I bought it. I've only run this dozer about 40 hours. At first I ran it with the tracks tight, like he had them, cause I was busy troubleshooting other issues. About 3 hrs ago I set the tension proper and I've thrown the left track twice since then. I guess the broken spring is why I'm throwing the track? I have some pics will post ASAP.
Please show us some pictures of your undercairage; rails, sprockets, rollers and idlers. The U/C may not be as new as the PO told you it was. You should be able to run it with the track sloppy loose and not throw a track unless you on some pretty steep ground or other adversly servere conditions
this is what a good undercairage looks like. Notice how the running surface and the edges of the rails are flat and the corners are crisp. Same thing with the rollers, you want flat running surface and nice tall and strait flanges. I hope your rollers don't look like the one on the left in the last pic
Take a small bar and pry outer part of idler ( where track goes around ) pry between outer bearing (bracket or porkchop depending on brand of machine ) I suspect you will find a good amount of slop. - if you see some fresh wear marks or grooving in bracket you do not even need to bother, the bearings will be gone in the idler
if the roller on the left is one that came off the dozer, there is something wrong besides the spring broken. something caused the one side of the roller to wear and that is what is throwing the track off. the rollers will not keep the track on. maybe rear mounts for the track frame, allowing the frame to walk or spread. chains and sprockets look pretty good. check play in the pins and bushings, see if it is excessive. definately, broken spring will not keep track tight. check front idler wear pads, it may be letting idler turn or **** out of line and make the tracks wear funny. there is definately something going on with your undercarriage. it is possible that the rollers were not changed with the tracks and sprockets last time. rollers and chains need to be square on sides to keep them on track.
I had the same thing happen to me about a month ago with my d6 9u. not sure of the differences in the track but I replaced my tension spring with a different one because the bolt down the center was broken and the spring was extended. I have some pics if you think they would help. but it is pretty trivial to fix.
The broken spring means nothing, all the spring does is absorb shock if you get a stone or debris lodged where it doesn't belong. Sounds more like improper track adjustment. Drive it forward and roll to a stop, lay a straightedge from top of idler to carrier roller on top of tracks you should have 1 - 1 1/2 inches sag. jr
That roller is not from the topic starter's machine. I was just posting those pictures to show hime the difference between good and bad. Your right on about the chains needing to be square
Correction: The rails might just be wore out. Have an undercarriage dealer near you send a product support rep out and measure it. Rish Equipment is near you; their ph# is (540) 887-8291. It may be that the rails just have too much slop from internal bushing wear and link wear. Your idler assembly will be sitting very much foward on the track frame if this is the case. Post some pics.
Here are some pics guys. not much to look at but she runs great! I know the pads are sad...they'll be getting changed this summer, along with a paint job. The rock guards are all beat to hell. I tightened the tension up a little---to what you see in the pic---took her out for a while, did some left-right turns. No problems so far. I tried to lever the idle wheel back and forth a bit. It looked like the whole "fork" assembly moved about 1/4" or so, but not the idle wheel on the shaft, which is good I guess. Note the busted spring, two places. I didn't take a pic of the pins. They gotta be within 90% of perfect round and haven't been turned. What do you think of the U/C?
Another pic. included one of my grill fab-up, too. Sourced the Cat grill off an Ag dozer in Oregon. Couldn't really get a pic of the other rollers without lifting the dozer. The inside flanges on those rollers are just as square as the outside ones you see in the picture above.
I wouldn't go any tighter than that. The U/C looks pretty good. What wer you doing when it threw the track besides turning (uphill, downhill, sidehill, crossing a ditch, ect.)
Rolls look good but it looks like a lot of internal pin and bushing wear, see the big gap @ the end of the links by the pin bosses. Couldn't tell real good but looks like a gap between the pads too. jr
adjustment looks ok. jr
Turbo, yeah I tightened it up a little today to see if it made a difference. I didn't work it too hard today , though. Kinda freaked out that I'm really gonna throw it for real. But, looked good today. Before, each time, I was turning on a fairly steep hill, say 25 degrees, once turning left, the other turning right, to go up the hill. Both times the track wants to come off to the inside. A third time I was pushing a pretty good load straight on level ground. I can hear the track get tight, squeaking, and the I can feel bam! bam! bam! which I guess is the rollers riding on the pins or something?? I know it's for sure time to stop then. Twice I've reversed and managed to get the track re-seated. Note picture of spring, left side.
Exactly. Have someone come out and measure it. We do it for free & I'm sure other dealers do too.
Broken spring does make a difference. Effects track adjustment. Installed length of spring should be 18.75 in. Maximum screw adjustment is 6.7 in. measured from back of turning nut to face of spring plate. (5.1 in with hydraulic adjuster) Maximum pitch increase measured across 4 track links (with chain stretched) is 27.4 in.