is there a condition that causes the rail to "cup" more then usual? meaning, that the rail is maybe 40-50% at the pin, and 20% 1/2-2/3's back. i didnt know if like a too- tight condition or something can cause abnormal wear.....thks
What kind of dozer are you running?
its on a 6r cat lgp. the pin and bushings have 55% left. by cat spec. thks for any foresight into the matter, im a slow learner
By cupping I am assuming you mean the valley that develops just behind the link pin boss. I am assuming your percentages are describing the amount wear left in the rail and that this bellying in pronounced on your tracks. The area under the pin and bushing bosses is essentially doubled in width by the preceding link so that area wears at a lesser rate than the areas under the internal struts. This is normal on all dozers. How much wear is there on the bushings and have they be turned?
We used to drag D8 tracks rails down on an asphalt road to help this condition. We always blamed the cupping on the way the rail only touches in the center while traveling on the idler because of its large diameter as opposed to full contact on the bottom rollers and smaller diameter carrier rollers.
bushing are in really good shape for the way the rails are worn, never turned that i remember. i bought this rig, but dont have it home yet.
Like DPete says, It is from wearing on the idlers. Look at new ones, and they only contact the idler in the center of the link. After the wear pattern you are describing (we call it "scalloping") then the entire length of the link is in contact. This makes for a rough ride, as each roller "climbs" over the bumps in the rail as it sits on hard ground. This wear pattern shows up on the high drive Cats since there are 2 idlers to roll over instead of one on the old machines. On a positive note, once it wears to ther point that the entire length of the link is touching the idler, it will not get worse, just stay the same. I guess if you want a smooth ride you can wear them out a bit more like DPete says to smooth them out.
Just do it when the grass is green on the shoulder, heh heh don't ask how I know. On the older conventional track D8's we would give a quick resurface to the rail at P&B turn if needed, what little rail heigth we lost off the high spots was better than shaking the machine on scalloped out rails or so we thought.
I hear you. I will also add that the smoothness factor is more important on a rigid track frame machine, like all low drives and high drives under D-8 size. The suspended bogey style suspension on the rollers of the larger tractors "roll" over the bumps with a lot less shaking of the machine than one with fixed rollers. PS, Do I hear a "hot" story line to follow?
Uh huh, sparks from tracks and dry grass don't mix but we got it out