Most very large crawlers have "walking" undercarriages. Maybe I am not using the right terminology. The front crossmember pivots in the center allowing the two track frames to not be parallel. Many small ones do not. Why do I prefer one over another in a 15,000 LB machine. Willie
It's an oscillating undercarriage. Basically a pivot bar up front attached the the frame and to each track roller frame. My 953 is oscillating but the D5G is not. It gives a better ride on the larger, heavier machines.
The mechanics were complaining they didn't get to lay under the machines to work on them enough, so they added several failure points to repair often. Gives the weldors and line bore guys a bit of game time as well.
Engineers, and architects should have to live with their designs. An architect who designs a crawl space should be put in it, and nailed in for a week or so. An engineer should fix his design in field conditions.
One of the reasons that the smaller machines do not have it is cost but we operators appreciate it,it does give a better ride.Ron G
It's not the economy. This system is cheap. It has advantages in light bulldozers, except for a mild stroke. On heavy tractors it provides a better grip with the ground tracks and more resources rollers. The problems - often fail cartridges, pins and dampers.