Steeling Up Track Life

With undercarriage components contributing up to 50% of the owning and operating (O&O) cost of a large earthmover, there is a big opportunity for you to increase profitability by investing in the latest technology - both in terms of hardware and management tools. But the results will really depend on where you're operating and how you currently manage your undercarriage.

Reducing sliding friction and increasing component durability can increase undercarriage life. "Weight, motion and stress are what cause wear," says Dan Drescher, product marketing manager for crawlers, Deere & Company. "A larger component can take more of that than a smaller component."

As such, Deere & Company has increased the size of several major components. "We are using larger rails, a little larger bushing, larger pins," says Drescher. "But as far as wearing, it would be the bushings and rails that would be the big drivers. There is more surface area and a little more weight there."

Fewer pin and bushing turns
Pin and bushing turns have traditionally allowed you to maximize your undercarriage investment. The alternative is to run the undercarriage to destruction, which can be much more costly.

But you need to identify the appropriate time to make these turns. "If you go too long, then of course you lose that opportunity," says Drescher. The longer you can go between pin and bushing turns, the more money you can potentially save.

Deere & Company's SC-2 extended life bushings are intended to maximize undercarriage life and extend the time between pin and bushing turns. SC-2 is actually a coating process applied to the bushing. The coating is sprayed on with the aid of robotics, then fused to the bushing by heating it in a hydrogen furnace.

This coating adds strength. "What SC-2 gives you is a super-hardened coating that can actually flex on impact. So it doesn't break, but it still wears very long," says Drescher.

Flex is important in undercarriage components. "If the coating doesn't flex a little bit, then it could fracture," says Drescher. "You get accelerated wear and a broken component."

The SC-2 undercarriage is managed like a conventional undercarriage - you just run it to a higher hour level before turning the bushings. Its lower maintenance cost makes return on investment especially rapid in harsh environments. "In the abrasive Florida marketplace, SC-2 lowers your operating expense by about 35%," says Drescher. "Return there would be significantly faster than it would be in someplace like Ohio or Iowa, where they have loamy conditions and you are going to get 4,000 to 5,000 hours on your undercarriage without SC-2."

Of course, not all technology to extend undercarriage life is hardware related. For instance, Deere & Company has taken advantage of the new electronic transmission controls to limit operator-induced wear.

"On the crawler products, the transmissions are electronically EH controlled," says Drescher. "That allows you to program in adjustable reverse gear ratios. In a lot of applications, you can slow down your reverse speed independent of your forward speed. It does save on undercarriage wear, because on anybody's undercarriage - at least on the bushings - you [generate] wear twice as fast in reverse as you do in forward."

Less sliding = less wear
Caterpillar actually eliminates the need for pin and bushing turns with the SystemOne undercarriage on its D3 to D6 dozers. "From the standpoint of reducing the owning and operating costs, it has really saved customers a significant amount of money because they don't have the bushing turns," says Tom Neeley, sales support manager, Caterpillar. "In addition, they are getting longer wear life. We have customers who have almost doubled the life."

The SystemOne track uses high-tech cartridges to hold the links together. Unlike a conventional pin and bushing design, the cartridge design doesn't depend on the link interface to remain sealed. The factory-sealed cartridge joints are laser welded, which prevents loss of seal compression and reduces the likelihood of leaks.