The potential damage from too much stop-and-go driving is greater due to the trend toward more fuel-efficient spec’ing, says Lon Miller, product service manager for Roadranger field marketing, the arm of Eaton that works with dealers and customers.
An easy step toward better fuel use is to lower the rear axle ratio to, say, 3.55:1, but doing so has other ramifications. “This is hard on the clutch, U-joints and drive shaft,” Miller says. “You can shorten clutch life as much as two-thirds in a stop-and-start environment by starting in the wrong gear. We’ve seen a substantial rise in clutch maintenance.”
A key sign of improper drive train specs is poor startability, Miller says. “You should be able to choose a gear where you let off the clutch without touching the accelerator and the truck should launch easily,” he says.
Starting a truck in too high a gear generates heat for the whole system and shortens the life of the clutch and flywheel, Miller says. Using the proper, lower gears means more work behind the wheel under miserable driving conditions, but it will save a lot of maintenance dollars.
The failure of many drivers to choose proper gears and the resulting drivetrain wear is one reason for increasing sales of automated and automatic transmissions, especially with customers in urban applications, Miller says. Automated and automatic transmissions always choose the right starting gear.
The increasing acceptance of automated and automatic transmissions should continue, says Darry Stuart, head of DWS Fleet Management Services. He sees the trend driven not so much by customers trying to minimize equipment breakdowns, but because more drivers see the equipment as a “creature comfort.”