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huntingtome1

Do Real Dozer Operators Backdrag?

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Does backdragging wear dozer sprockets, bushing and pins prematurely or is that just another myth orginated by Cat?

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It wears the bottom of the blade!!! would say its easier on the machine than pushing

thanks Sam

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Generally, good dozer operators will hesitate to back drag. Most track shoes were designed to pull hard in a forward direction only. In forward, the grouser pulls the track link against the rollers, while in reverse, the load pulls the track link away from the rollers, and then slams the link back against the rollers, as the roller runs over the grouser, causing accelerated wear on both kinks and rollers. A machine with the tracks on backwards will also wear out undercarriage very quickly. Also the dozer is meant for pushing only, backdragging damages the treaded ends of the cutting edge bolts, and premeturely wears out the frog of the blade. (The part that the cutting edge bolts to)

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Once in a while even a good operator

will use the back of the blade to drag

dirt out of a hard to reach spot. Then

he will spread it going forward. Yes

if you backdrag enough it is hard on

undercarriages and dozer blades. If

a cat was built for working dirt in reverse

it would have cutting bits and face on

back of dozer. Dozer blades were built to

take the stress from pushing not dragging.

Backdragging is hard on the braces,pins,

bushings,and trunnions on the blade.

It is a trade mark of an inexperianced

operator. What Cat instigated myths have

you heard?

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------or if some dumbarse truck driver drops his load of expensive metal, in a heap, on the bush road, and you have to scratch it back onto the carridge way---as to not waste it

without a grader, and with little material to play with, back blading, with an angle blade, on float, but still using the tilt rams---you can make a ghee whizz job-----it is acceptable in some cicumstances

when you see a neat finish, with grouser marks printed all over, it sure looks good-----

Mike

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I have been known to backdrag but mostly with the blade on float or with an old D7 cable lift blade. I did operate a D7E in the Nat. Guard thathad swing away rippers on the rear of the blade that would dig on the backstroke and fold away when dozing forward. They only stuck down about 18" below the blade and were not much help at all.

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Sawmill

You trying to tell me you are supposed to use the front of the blade :(:( Thought the front was for rolling things out of the way so you could back drag it :huh::huh::huh::huh::ph34r::ph34r::ph34r::ph34r::ph34r:

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Back dragging is easier to smooth out loose dirt than going forward. Due to the shape of the back of the blade you obviously can't dig fresh dirt going backwards so how can you hurt anything? There is one thing worth considering. Going forward the forces go from the sprocket to the track and directly into the dirt. Going backwards the tension is on the top of the track and tends to pull the front idler back against the tensioner. Any heavy backwards load like pushing a scraper with it going backwards could cause trouble by causing slack, etc. I've been trying to figure out how the forces act on Cat's stupid high drive system but haven't had the time to work it out.

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did ya ever try cutting your steak with the knife upside down? it doesn't work all that well. Also try and distribute your turns evenly, by this I mean not always turning one direction all the time, also when working on side hills, try and give each track a equal time on the uphill side, these things will make your undercarriage last alot longer.

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Well, I've been around some excellent operators, and was even accused of being adequate once :) , but I've yet to see an operator that didn't backdrag something, somewhere, if for no other reason than not to leave grouser marks in fresh work. But as others have said, it's always in float to just distibute a little loose material. If you're needing to do more than that in reverse, you probably need a little more time in the seat. :P

Chads

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Hi Tom As far as operating, I know it wears the bolts & frog & an old highly experienced owner/operator said the material is always laid down more even when you have a bladeful & it rolls in front , he said it always settles uneven when backbladed, I saw alot of his roads & they were great. For undercarriage wear, when you work backwards you are pushing the track under , instead of pulling it under & pushing it over the track frame & top idlers, it causes the bushings to climb the sprocket tooth( same as high speed reverse wear ) which puts more load on the edge of the bushing & tip of the sprocket tooth. As said earlier too, it causes roller & idler tension mechanism stress. Thanks fer the pics, Russ B)

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If you're talking about trying to EXCAVATE material by back-blading,no...you need more seat time pushing forward.

As for finish/tidy up work,my clients always like the look of a neatly backbladed surface,as you're leaving the job (float position only).Gives them a nice surface to work with.

Hey MIKE...we must get the same truck drivers on our jobs!....the ones that tip the load 20 metres from the tip face...........

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If you're talking about trying to EXCAVATE material by back-blading,no...you need more seat time pushing forward.

As for finish/tidy up work,my clients always like the look of a neatly backbladed surface,as you're leaving the job (float position only).Gives them a nice surface to work with.

Hey MIKE...we must get the same truck drivers on our jobs!....the ones that tip the load 20 metres from the tip face...........

u can always tell a truckie

just cant tell em much..................................... :P

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Q: What do truckdrivers and refrigerators have in common.

A: When you shut the door the light goes out. :lol:

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when we grade off a lot thats to be loamed by a landscaper we dont back blade. the landscaper ussually has a dozer or skid steer on hand. when we loam the lot itself we backblade on float the whole thing. the laborers complain when they rake out all the track marks.

p.s. if your ever lost in the woods...just bang in a grade stake and when the dump truck comes to run it over, ask the driver for a ride out.

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Cheers Terry, that is much clearer now. Rocko59 explained it much better but it was what I was trying to say but I think I got myself tongue tied.

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Cheers Terry, that is much clearer now. Rocko59 explained it much better but it was what I was trying to say but I think I got myself tongue tied.

It all depends what you are trying to do .To state that|you need more time in the seat" is a total load of bollocks.Anyone who has worked in muskegg at sub zero temps will attest to that.We would open up muskegg in the winter months for rigs to move on .\at 30-40 below ,the road surfaces freeze and get frost heaves ,making them as rough as guts ,plus getting ruts from the wheeled vehicles.Once the road is formed on muskegg ,you dont cut it again going forward,so you backblade it ,dragging loose stuff on the top and some snow..Hopefully you get enough to fill in some of the ruts,and it will freeze in ,and help smooth it out.This is an ongoing thing,and over time as the frost is pushed down,the road will take more weight.If there is a grader around ,that helps,but normally there isnt so backblading is the norm.We would backblade for miles sometimes,two or more cats Each time a bit .more frozen stu ff would get dislodged and keep filling the ruts.Sometimes we would have a water truck on as well ,hastening the freezing process.As backblading was done in the "float"position,therfe is minimal loading on the cat,and no appreciable increase in track wear than from normal reversing,as it is all low speed.These were older cats with out the "high drive" tracks,6,s,7,s and 8K,s

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In my case I don't think I will have any dramas since I only want to clean up a few tracks around my 110 acre property. I am very new to dozers and I have found that if I push the dirt to where I want it, I can then dress it better by back blading which even removes my own track marks without doing any damage to my old dozer. There is only around a mile and a half of tracks that I will bother with, the rest can stay as they are.

Being as new to this as I am, it is interesting learning how this thing works and the repercussions of my actions in the way that I use it.

While I have a good grasp of things mechanical, I am still learning every day, even at the wrong side of 50!

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I backbladed a lot to start with, but experience and better dozer tractors means I don't as often any more, I'd try it as much as you can going forward, when you get so frustrated you can't take it anymore go ahead and backblade.

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Just curious why your average brain-dead truck driver can load a dozer or boom tractor smoother & without tearing up the deck of a loboy than the know-it-all operator! :rolleyes: Have seen drivers load a boom tractor with a glass of water on the goose-neck & not spill a drop, never saw a so called operator do the same with a blade on. :huh:

Q: What do truckdrivers and refrigerators have in common.

A: When you shut the door the light goes out. laugh.gif

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I've noticed that myself busman7.

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Hi, Folks.

For what it's worth here is my take on this question. (And PLEASE, remember to be gentle with me as I have only been doing it for a short while, just a tad over 47 years if I remember rightly.)

When you are travelling forward with a crawler tractor, bare or with a blade, the track is drawn by the sprocket from the idler, under the rollers and to the sprocket in a smooth stream under tension all the way and all the slack is up on top over the carrier rollers.

When you are travelling in reverse, all the slack is drawn away from over the carrier rollers and bunched up between the bottom of the sprocket and the rear-most bottom roller. This bunching up causes faster internal wear on pins and buhes and faster external wear on the outer surfaces of the bushes and the contact faces of the sprocket 'cos the bushes are bunched up against the sprocket teeth instead of being lifted off at the optimum angle like they are when all the slack is up on top. In addition, this wear is taking place on the opposite sides of the pins and bushes from the ones that wear when travelling forward, both internally and externally. The more slack there is in the track, the worse the effect. Likewise, the more load on the tractor when in reverse, the worse the effect.

When you KNOW what you are looking for, you can sometimes tell a tractor that does a LOT of work in reverse by the comparative wear patterns on the front and back faces of the sprocket teeth and on what is the front face of the bush when the track is up top.

On this aspect of the great back-blading debate, I would put it thisaway. If you NEED to backblade, go for it. There are some situations where it is the only practical way to 'gitterdunn'. How-wevver, if you are back-blading just 'cos you like the look of it or, assuming that you have some skill and ability and are not just a raw beginner, 'cos you are just plain too lazy to do it going forward, DON'T ask me to pay your track repair bills.

On the issues of damage to the blade base and the cutting edge bolts, back-blading is not much of an issue in most softer materials with NO rock, although it does place extra strain on the trunnion bolts 'cos they are pulling the load intead of simply holding the end cap on to stop the push arm falling of the trunnion. In rocky material, there is way more potential for damage and the harder the rock, the greater the potential.

As far as this question applies to the high sprocket drive crawlers, there is still the potential for increased wear in reverse but not to the same extent 'cos the slack in the track is between the sprocket and the rear idler rather than bunched up between the bottom of the sprocket and rear track roller. With both drive designs, there is still the issue of added load on the track adjusters and the front idler mountings. On the high sprocket drive crawlers, there is also added load placed on the cannon and shaft of the front idler mounting.

As for the comment about the "myth perpetrated by Caterpillar" about increased track wear in reverse, I don't think I have yet read an operator's manual from ANY manufacturer that didn't mention this aspect of track maintenance - - - - - before or after the high sprocket drives came on the market.

Hi, Busman7.

May I ask what you are calling a 'boom tractor' that has a gooseneck? If you are referring to a unit on rubber tyres, yes it is possible to load a rubber-tired unit more smoothly than a tracked unit most time 'cos you don't have to contend with a point of balance.

Just my 0.02 from a bloke who is still learning.

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Yeah that is logical, and kind of what I was trying to say in another thread that ended up discussing this subject, and that is why TerryInOz bumped this thread, so that I would have a better understanding of what back blading can do to a dozer.

This was my assumption: "Yeah I think I know what you mean, and while pondering the other ramifications I was thinking that instead of "pulling" the tracks from the bottom of the drive sprocket, it would be trying to "push" the tracks forward, does that make any sense? While pulling the tracks they are under tension but while pushing the tracks they will have a tendency to want to bunch up between the drive sprocket and the front idler. Does that sound logical?"

I am a VERY raw novice and I don't want to destroy my old TD14A, but like they say, all things in moderation or something like that.

I assume that its part of the learning curve, and I wish I had the benefit of your experience, but that is something money cannot buy.

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The thing I've noticed about operators being noobs as far as loading goes is most truckers know to use the blade or bucket to keep the tractor from slamming when it breaks over,for some reason most operators load with blade or bucket 10' off the deck.

I loaded mine that way cause' somebody welded fenders on my stepdeck and someone else welded some bar on so that the crawlers wouldn't scramble for purchase.

Just don't try to pull a huge load in reverse and it will be okay actvd.

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