Overdrive Magazine | Trucking Business News & Owner Operator Info
Issue link: https://read.dmtmag.com/i/757641
December 2016 | Overdrive | 45 SEVERE SERVICE E aton's 7-speed Procision automatic transmission was designed to compete with Allison's 2000 Series RDS in the vocational truck segment for auto- matic shifting. I recently took the unit for a spin around Navis- tar's proving grounds in New Carlisle, Indiana, in an International DuraStar matched with Cummins' ISB 6.7-liter diesel engine. The transmission's dual-clutch design prese- lects the correct gear for smooth rear-wheel torque delivery that lacks clutch lag and jerking, thanks to the absence of a torque converter. One clutch is fully en- gaged when the Procision is in gear, while at the same time the transmission's advanced ECMs are pre- selecting the next gearshift based on throttle input, the truck's load and data from the unit's grade sensors. Then the ECMs "cal- culate how much torque is being demanded at that point," said Jeff Spitzner, Eaton senior account manager. When it's time for a gearshift, the fi rst clutch disengages, and the other engages. Because one of the clutches is always closed and the unit isn't re- peatedly opening a torque converter, there is also a natural braking eff ect when coming down steep grades. For steep inclines, Ea- ton's Hill Helper prevents the truck from rolling back or forward for up to three seconds. This allows for a more controlled uphill launch and keeps you from crashing through the grille of the car behind you. I launched my DuraStar eff ortlessly from a dead stop up a steep grade. Roll- back was minimal, and the truck accelerated smoothly at half-throttle. A tangential benefi t of the Procision is that its gears shift at a lower rpm, which reduces engine noise. On a non-full throttle launch, a Proci- sion will shift in the 1,300 to 1,400 rpm neighbor- hood. You'll be in fourth or fi fth gear without even knowing it because the shift is so smooth and the engine is so quiet. Creep Mode allows con- trolled low-speed driving in parking lots and loading docks without applying the accelerator. Forward and reverse creep speeds are adjustable independently to allow a lower speed in reverse. The Procision clearly shined at low-speed maneuverability. A fully optimized Proci- sion can off er upward of 10 percent better fuel economy than a torque converter-equipped automatic, another selling point for drivers interested in keeping more pennies in their pockets. With almost car-like shifting, Eaton's hydrauli- cally controlled Procision and its smooth shifting can take a lot of work out of a work truck. Easy shifts from Eaton's Procision BY JASON CANNON Jason Cannon is equipment editor for Overdrive. Eaton's 7-speed Procision automatic transmission was spec'd in an International DuraStar matched with Cummins' ISB 6.7-liter diesel engine. The Procision's gears shift at a lower rpm, which reduces engine noise. Severe-duty shocks Gabriel's FleetLine shocks for Western Star, Kenworth and Mack models have an improved anti-corrosion coating, valving rates engineered to compensate for initial suspension softening and a preloaded pis- ton ring designed to combat wear. A mist- ing reduction seal helps reduce oil loss. Gabriel Ride Control, Gabriel.com