Good day folks! I’m doing the undercarriage on the old farm dozer, a CAT D6N SN ALY00699. Rollers were ordered by another mechanic before I came on and I seem to have a lot of double flange rollers. Then looking at the machine (he did one side before I took over) neither side is the same. I’m no expert on dozer undercarriage, I’ve just done a few pad/chain swaps and replaced a bunch of idlers. I’d like to expand knowledge a little bit and ensure we get some decent wear out of this. My question is: What is the correct order of double and single flange rollers? Or if there are multiple options, then what are the advantages of one arrangement to another? Thanks!
According to the system this is an LGP machine that has 8 track rollers per side. If that is the case then then the "standard" track roller setup according to the manual should be 4 x single flange and 4 x double flange rollers per side arranged as follows from front to rear: S - D - S - D - D - S - D - S
All the dozers I've ever worked on started with a double by the front idler and ended with a single by the sprocket. I usually put two doubles by the front idler and another at the center of the track frame. System one might have a different recommendation but we always put a double on the front.
I guess I am curious as to the benefit of one or the other, and why all rollers aren't double flange. Perhaps releasing retention of material is the benefit of adding single flange? I've changed rollers numerous times and have paid attention to which should go where, but I haven't wondered about why the singles/doubles go where they do until now.
We put the double right behind the idler to hold links in line with the track frame when going forward. It also seemed to hold the track on the idler better when in reverse. The single in front of the sprocket allowed the track to move a little to engage the teeth. We asked the factory years ago about the doubles and singles and were told the singles save some money. I like a double in the middle because on a straight track frame the machine would pivot over a ledge on the center mounted roller.
Don't think having more double flange would hurt anything. Double flange keep the rails straight. Just need single at the sprocket on low track machines.
to allow for mis aline ment at both idler and sprocket NIGE quote from THE book
I've been trying to lay hands on the info in print somewhere but certainly as far as high-drive tractors are concerned I was always under the impression that the Golden Rule always stated that the track roller closest to each idler (F & R) must be a single flange roller because misalignment between an idler and the adjacent track roller could result in excessive flange wear on a DF roller.
I was thinking that had to do with suspended track frames. I’ll pull some records from old appraisals and somewhere I have the track book for that time frame.
To the best of my knowledge, the difference between single and double flange rollers is just for track guidance. Here's a table of modern medium tractors. Document number M0129927.
Interesting, thank you!
Here is a quote out of the last track manual I got. "From the chart which follows, you will note that the rear roller (the roller nearest the rear idler) is a single flange roller. If a double flange roller were used as the rear roller, interference could occur between the inner flange and the rear idler. Therefore, a double flange roller should NOT usually be placed in the rear position." Here is part of the chart that shows the D6 high drive configurations. It does show a single flange for the front. D6H, D6R 6 SDS DSS D6H XL, D6H XR 7 SDS DSDS D6R XL, D6R XR, D6R XW D6H LGP, 8 SDS DDSDS D6R LGP This is from the chart for the low sprocket machines of which I have the most experience with. D6 6 S D D D D S D6 LGP 7 D D S D S D S D6B, D6NC 6 S D D D D S D6C, D6D 6 D S D S D S D8NC (8.00") 7 D D S D S D S D8H, D8K 7 D D S D S D S D8H, D8K 6 D S D S D S D9, D9D, D9E, 7 D D S D S D S D9G, D9H
Well, certainly some good information here. Certainly makes sense how alignment issues could occur between a double flange and an idler. Guys I appreciate the input!