BorgWarner | K32 Durospeed Fan Drive

New two-speed drive is specifically designed to deliver reliable cooling for construction and other severe operating conditions. While on/off fan drive models offer durability and fuel efficiency for over-the-road applications, BorgWarner engineers note, the K32 DuroSpeed suits severe service vehicles by reducing fan engagements—boosting reliability and lowering noise.


The K32 DuroSpeed suits fans up to 32-in. diameter, hence a broad range of vocational and off-road vehicle power units. BorgWarner engineers underscore the drive’s potential for such trucks, which have less ram air cooling than over-the-road models. As a result, DuroSpeed magnets prompt higher fan speed when the clutch is disengaged. Reduced clutch engagement frequency preserves the Powerwedge liner service life.

“Dump trucks and other vocational applications have very different cooling needs than line haul trucks,” says BorgWarner Thermal Systems President Daniel Paterra. “Our testing shows the DuroSpeed fan drive’s innovative flux ring design enables this clutch to run 70°F cooler than competitive offerings. The cooler internal operating temperature increases bearing and liner durability, allowing nearly twice as many engagements over its lifetime.”

In severe-duty applications, on/off fan drives are continually engaging and disengaging. When disengaged, engine temperatures rise quickly, causing the clutch to engage repeatedly. The pneumatically actuated DuroSpeed is designed with a higher disengaged fan speed to prevent engine temperatures from rising too quickly. As the drive engages and disengages less often, clutch life increases, noise decreases, dust buildup in the radiator is minimized and more horsepower is available—allowing the vehicle to achieve higher work output. The DuroSpeed fan drive has no spinning air connections to wear, inspect or service, and is designed to operate at lower temperatures for longer bearing and liner life. Weighing 5 to 10 lb. less and using 11 fewer components than comparable units, the clutch also contributes to fuel economy.

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The K32 DuroSpeed’s two-piece, flux ring assembly kit (right) equips the K-Series all makes clutch (left) to run up to 70°F cooler than competitive offerings, BorgWarner engineers note. The Powerwedge friction liner (second from left) allows full clutch engagement at 1:1 speed, where cooling demand peaks. A lower internal operating temperature increases liner and K-Series bearing durability.





To reduce complexity and minimize upgrade costs, the DuroSpeed modular design uses the same K-Series clutch unit for all applications up to 32-in. fan diameter. Any BorgWarner Kysor on/off series fan drive can be easily retrofitted to a K32 DuroSpeed with a two-component conversion kit. The new drive joins the manufacturer’s full line of airflow solutions for a variety of cooling needs. — BorgWarner Thermal Systems, Auburn Hills, Mich.;