Ok, I'll preface this by stating that I'm new to excavators, specifically minis. I'm just looking for some knowledge from experienced users. I picked up a Bobcat E42 earlier this summer, and recently experienced my first de-tracking incident. I've been wondering when it was going to happen, and dreading it. Fortunately, it wasn't really that big of a deal, and I easily got back up and running. This is a new machine...less than 50 hours on it. I've been keeping an eye on track tension, making sure it was within Bobcat specs, so that shouldn't have been the problem. Other than this incident, it's been a great machine...very pleased. My questions are: What really caused it? I was in a fairly open grassy/sandy field, dry conditions, doing some stumping work. In the middle of repositioning, I heard a little popping sound from the RH track, and boom, it was off. The undercarriage was pretty clean, no sticks or rocks or other debris in the way. I always figured when it happened, it would be because of running over rocks, logs, stumps at an odd angle, or trying to spin around in muddy or loose conditions, or picking up something in the undercarriage...none of which happened. Are there techniques that I should be following regarding moving, turning, repositioning that will put less stress on the tracks and minimize the chance of de-tracking? Kind of late now, but are there makes, models, design characteristics that more prone to this condition than others? Since I'm still under warranty, could there be a problem with the machine that I should have the dealer check out? Hoping for some great answers...thank you!
Twisting on the the tracks is hard on tracks and rollers, whole undercarrige, but sometimes you have to do so based on the space you are in but in an open field I would practice picking up one end of the unit with the bucket and spinning on the end of the tracks while turning the cab. It is hard to describe this in words but their are many U-tube videos that show what I am talking about. Just google "turning excavator with bucket." Here is a thread also, HeavyEquipmentForums You stated you kept an eye on track tension, did they get loose often and you tightened them or you just checked them? How did you check them? I had an E50 last year the tracks loosen up about every 10 hrs from new. Found out Bobcat grease zirks that you put grease in to tighten the tracks had a bad check valve. Had to replace both (under warranty) and problem when away. If you operate equipment long enough, you will throw tracks from time to time, there are those who have had it happen and those who will... I check tracks daily during warmup and have still throw a track or two over the years. My dads rule was, if you did it, you fixed it, nothing is better at teaching than 98F in August in AL woods putting tracks back on a D6 dozer cause you were too lazy to keep them tight.
hi otg, Im like you with new machine and waiting to pop a track. Im a newbie also and not thrown a track yet but i have busted tracks (destroyed them) on other machines and even though its inevitable they will break im sure i contributed to there demise through poor skills on my part when leaning the basics. I can only speculate but i think the tracks become damaged internally and weakened at the cables on the lug when you crush rocks in the sprocket or idlers. When the tracks are new they seem to crunch rocks ok but when they get old and soft they ether burst or create a soft spot on a lug just waiting for the right conditions to fail. If you are aware of rocks in soft material you can maneuver and dodge most of them but some roll in there you don't see when you are digging and turning. So in your case maybe you ran over a rock and it pushed one of the internal lugs in your track in just the right place when you were turning. It would want to be more of a rare occasion than happening to you all the time one would think. The issue of popping tracks off seems to be more prevalent with rubber tracks as most steel tracks have guides behind the front idles to help keep the tracks on. Some machines only have one lip on the rollers under your machine which is not so desirable in keeping the tracks straight on slopes. Maybe someone with bobcat experience with your machine might chime in with more info?. My machine is zero swing and under counter balanced in weight and if i was turning on the spot the track under the counter weight will always be the track sliding on the ground. So when you know that when moving through bad ground you just stick and boom out a little more across the track you don't want to slide. Your machine has overhang and better balance so if you are turning on the spot you are grinding both tracks with big side pressure. But you can stick out more like me or even bucket down and lift the machine slightly to make sharp turns. I try to make larger turns but what i have noticed try not to force your turns. What i mean by that is as you are moving and turning with blade forward and house faced forward all of the weight is mainly on your front idlers. As the machine goes over high and low spots in the ground you will feel the machine spin easy on a high spot and you take advantage of that. The bad side to all this off course is the cuts to the sides of your tracks so you carn't win. Good Luck with your machine, Cheers
tracks typically stretch (and loosen) the most in the 1st 100-200 hours. most of our service calls for a track off is on a very low hour machine, (including CTL's)
Thanks for the replies. I've been checking track tension every 8-10 hours and pretty sure it was within factory specs. Being a newbie, probably have a thing or two to learn about tracking and re-positioning under different conditions. Something to work at...
As the saying goes OTG, "experience is the best teacher". There's a number of things that can flip a track, but a very common occurrence is something gets the track off center of the bottom rollers, could be a staub sticking up out of the ground, could be an embedded rock, even turning the machine on uneven ground. You could have encountered one of those situations, which pulled the track off center of the bottom rollers, and kept walking a distance without even noticing it until, pop, it came off. I once had a rental customer that flipped a track on a T300 driving it straight across an open field. Obviously, there was nothing on that route that would flip a track, he had to have upset it when he was back in the woods before he traversed the field. In many cases, when one pulls the track off center of the bottom rollers the machine will have a different feel when tracking. Maybe a vibration you didn't feel before, maybe on track seems to take more engine load to make it drive, but they typically do something that would make you take notice that something is wrong. If you get to where you notice this, stop and check it out, you may find you can correct the discombobulated track before it actually flips.
e 50, and it had a bad zerk from factory....lets the grease out....did it twice and then changed dealers...fixed properly then....I keep the tracks a little tighter than what they say, and also make myself check them regularly...Tony
I would expect things to loosen up in first 100hrs as CrewChief888 noted. I don't get wound up over loose tracks...but am mindful of turning 'hard'. Having both tracks turning while making a turn will limit one track from binding in dirt. Doesn't take a lot to throw a track. I will say if your throwing tracks a lot, you either have tracks way too loose or your putting too much force on rollers and idler (quick way to destroy your rollers). Avoid high speed turns, carrying heavy weight, or being in a rubble pile, and making sharp turns. They put a lot of side torque on rollers (they are not made to take that punishment). I'm in rock most of the time (BC), and if on jagged bedrock, I will lift a track with arm and spin the other track to turn. But if in loose dirt, I don't bother... I assume you've adjusted your tracks a few times...after adjusting zerks, see if any are leaking grease after tightening.
Thanks for the advice. Much appreciated.