I have been running iron since 5 and one thing that i could never completely understand was the corilation between speed and wear on U/C. my dad and some of the old boys from the company always told me that walking a hoe in fast mode or running the 850c in 3rd was hard on u/c. I always thought that if you were a good dozer op. you could cut grade @ 2.5-3 Atleast i can on ours. So i am traveling the same distance as i would at a slower spd and doing the same amount of work, so the only diference is that i am being more productive. what are your opinions on this topic?
Speed kills...:d
But how? same distance same wear as far as i'm concerned, that kind of speed produces no more heat than it would going slower would it ??
Here is the answer. http://http://www.deere.com/en_US/cfd/construction/deere_const/media/pdf/DKB765.pdf
You don't produce enough heat in the undercarriage of a machine to do any damage. All of things in the Deere publication listed in the post above explains it very good. One of the better publications I have seen on the subject.
Like Greg says, that is one of the best presentations I have seen to explain U/C wear and its causes. I especially like the graphic showing the wear in reverse. I have understood this for many years, but never seen it explained in such an easy to understand way.
High speed operations cause impact loading on the sprockets and bushings, especially in reverse. I have seen up to 30% faster wear for dozers with operators who continually run third gear reverse. I usually advise customers that I like being paid to work on undercarriage, so keep up the good work. Excavators use a different kind of track link and they don't move nearly as fast. I generally only ask operators to make sure the sprockets are always on the down hill side of travel. Reverse operation still wears out chain faster but excavators are only carrying their own weight.
So don't back up, don't turn, don't work on hillsides, don't work along crowns are swales, don't go fast, don't go far and your undercarriage will last longer!!!
Makes you wonder why some old standard shift dozers had five forwards.
Wow alot of that stuff i knew already but that definately reinforces my dad's point. I think i will print that off and go through some of that material on monday's start up meeting. Thank you guys :drinkup
mmm so if i don't use the machine it will last for ever!!!! wow i just saved thousands in fuel and maintenance
All sarcasm aside, there are slight changes to operator procedures that can be made to prolong undercarriage life, after all undercarriage accounts for more than 50 percent of maintenance costs of a dozer over it's life.
Interesting article. If you take the information about forward and reverse wear, and apply it to a high track. The high track "even in forward" is going over and idler "rear" with track chain loaded, where as a low track is not.
Which is why parts of the U/C on high tracks lost some life from the beginning. It led Cat to develop better components to get the life back up to the acceptable range. The arguement is that they are more productive, so it balances out. Not always though. Notice the smaller Cat machines all going back to low drive.
What makes them more productive??
850J. I set the reverse speed to 130% and boy the bushings on the chain literally cracked and started flaking off within 300 hours.
It eliminates the final drive system that oval track dozers have. The drive sprockets don't have to carry the weight of the dozer only drive it so more pushing power. The tracks fallow the contours of the ground better so more traction and smother ride. I'm sure theres more too.
So what's the verdict? Go slower and take more tome to do the job, but have your U/C last longer. Or go faster get the job done quicker, make more money, but more maintenance?? im confused.
From my very limited experience with dozers, you can be just as productive and sometimes even more productive doing big heavy slow pushes than by fast and light pushes, and reduce the wear on the undercarriage. I haven't run any hydro dozers, so I can't say what to do with them, but when pushing a full bladeful on a powershift push cat, first gear gives much better performance and efficiency than second. You also have more time to think and control grade better in first gear. In other words, you can get an area to the basic (but not finish) grade just as quickly and perhaps quicker by doing full pushes at a slow speed rather than by going fast and doing light pushes. You normally can't get full pushes going much faster than 1st gear speed. Thus, slow but full pushes are just as productive as fast light pushes, but slow pushes reduce the wear and tear on the undercarriage. For smoothing and final grade though, 2nd gear seems better, because you just want to make fine adjustments to a large area quickly, and no great earthmoving pushing force is needed. 3rd gear is just for travel around the job site in a 3 speeder. I'm no real dozer operator though, I've just messed around with them a bit, so don't take my words as the 'facts.' What do the real dozer operators here think about this?
You would make your undercarriage a lot happier if you never used 3rd gear, especially in reverse.
Saving wear and tear on the machine does not always equate to saving money. There is a fine line where things like extra fuel, operator wages and lost productivity cost more than a little wear on the tracks. For instance. Part of my job is stringing pipe. Sometimes I have to drag it 2 or 3 miles down a right of way. Now there are 6 or 8 guys and 3 or 4 machines waiting on me to get back with it. Do you want me to run 2nd or 3rd? What I am saying is there is a whole lot more to the cost of operating a dozer than the wear on the tracks.
Well put Galute IMO, it comes down to the individual situation. Having the most information available lets you make the decision of whether the speed makes sense. For a one man operation, slower is generally better long term. All you are affecting is your own time, and saving large costs. If you are like Galute above and have a large number of people, machines, and deadlines waiting on you, then the savings on wear by moving slower is dwarfed by the costs of the people waiting around. In that case, still remember the difference between forward and reverse, if possible. In between the extremes, add up the costs, and operate accordingly. In my experience, 3rd gear will cost around double per hour, and more like triple if it is reverse.
Ok now what about corks ? I have a 7 and a 850, 450dlc and 350dlc all corked up, I think that is the hardest on u/c yet, But with out them on those machines would be useless. So the boost in production should cover the extra wear? In my experience with a hyd stat dozer i found that if i have it in 3rd it will push as much as in 1st and as you gradualy loose your dirt you start to pick up spd. My dozers never runs by the hr so i figured that spd was more benificial to production than a expence, an expence that i belive is already included in a oporating cost
what are corks?
I assume it's ice lugs
track speed owned my first D6c 43 years ago and still run eight D8,s on scrapers, also eight LGP high drive dozers,and high speed kills tracks,costed and proved this out years ago,had third gear removed from the D6R,s via a laptop in under five minutes,the D6H,s will take a bit longer,third is not a working gear its only good for ragging tracks out
Ok, i read it all, and since i pay for all repairs, now i understand i can only go forward with a light load on level ground! ah well, The price of doing business huh? good article.
The nature of most dozer work involves doing things that are contrary to "best practices" for undercarriage life. That is just a fact of life. The difference comes from recognizing when you have poor conditions, and adjusting operating practices to reduce the amount of time spent in harsh conditions. Much of it is simple, like not backing up long distances. You will always back up, but if you have to travel, turn around and go forward. Dont ride up on the edges of your windrows. It side loads and wears pins out. Keep slack adjustment proper, and re check it when you change working conditions. Make gentler turns. A gradual turn stresses things less than a locked track turn. Spinning tracks should not even have to be mentioned, but many do. If you are spinning, you are wearing it out without the benefit of generating work. Speed going forward is bad. Speed in reverse is 3 times bad. Almost all dozer work is harsh, what you need to do to get the best life is minimize the worst of it. The operator is the biggest variable in the wear of the whole machine, but especially the undercarriage.
I hope some people are being sarcastic, Bigger dozers such as D10's, D11's, and maybe D9's spend over 70 percent of their track life doing the opposite. usually you see a D11 on top of a mountain pushing down then backing back up. Hope some newbies don't get the wrong impression then get their chance to sit in the seat then after this decide to push down turn around and head back up the hill in a forward gear. For guys that think 3rd gear isn't much wear and tear on a machine go ask any McAninch mechanic how much abuse it really is.
In case I was not clear, "travel" is not the same as backing up to make the next push. Whatever the push distance is, that is how far you back up. Traveling from point A to point B is a different story, and should be done going forward.
Along time ago were I worked we had quad tracked 9G's loading 666's in mine stripping operation I think we had 8 or 10 DD9's and maybe 15 plus 666's the rule for the push cat operators was back up in 3 gear take 3 days off do it the second time pick up your check. We had at least 1 DD9 in the shop for complete overhaul from the bare frame up and 666 for the same thing
"boss, I was hoping to take off Thurdsay & Friday. The wife & I have plans for the weekend." "NO WAY! WE ARE TOO BUSY AND NEED TO FINSIH" "yes sir, I understand. BTW, where's that DD9 I've been wanting to run some?" ....:drinkup
RolyD8K, Wit your D8's pulling pans I take it you run in third gear when in transport mode. Here, I load in first gear for the most part, sometimes in second when real easy going stripping top soil, third for transport. Use a D7 to push in real tough cutting ground. Like others pulling pans I have found undercarriage life to be quite good because of not using reverse much, and lots of long straight pull hauling.
Here's some good info from Cat http://www.cat.com/cda/files/870564/7/WEDQ1007+EAME.pdf
here is the undercarriage wear info from cat. http://www.cat.com/cda/files/1465543/7/undercarriage focus on the operator.pdf and even more: http://www.cat.com/cda/search/searc...s=25&x=7&footerURL=&searchField=undercarriage
I always cringe whenever I have to run the old D6H XL in 3rd to hurry up and get over to where the scraper is. It sucks being one of the 3 operators that knows how to push pull but they stick a new guy on one of the 627s instead, but I guess he didn't know how to run 6 either. We had to have the local John Deere dealership limit the reverse speeds on our 3 700Js because they were chewing through the pins and rails.
no third gear Hi Greg,no third gear used,load in 1st gear,and run in 2nd gear,loaded or empty be it hire work or contract,it would need to be one hell of good price to run in 3rd.