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The
Banks SmartLock
To get maximum performance from a Banks
Brake on a ’94-03
Ford 7.3L Power Stroke turbo-diesel or a ’92-03 Dodge/Cummins
5.9L turbo-diesel with an automatic transmission, the SmartLock
is a must.
By C.J. Baker
Regardless of what you
call it, a diesel engine exhaust brake, diesel exhaust backpressure brake, turbo brake,
a pickup or RV jake brake, or simply an exhaust brake, such a supplemental brake is
a great investment for diesel motorhomes and pickups that are used to haul heavy loads,
pull trailers, or are used in hilly or mountainous country. That includes just about
all diesel pickups and motorhomes. Such a brake not only adds braking safety to the
vehicle, it also saves considerable wear on the vehicle’s service brakes. This
is because diesel engines provide little or no braking effect when the driver backs
off the accelerator pedal (see "How
an Exhaust Brake Works" elsewhere on this site).
An exhaust brake creates
the diesel exhaust backpressure to generate engine braking. This braking force then
needs to be applied to the rear wheels of the vehicle. Unfortunately, Ford and Dodge
pickups fitted with automatic transmissions don’t transmit the engine braking force
created by an exhaust brake to the rear wheels. These vehicles were not designed with
an exhaust brake in mind, so when the driver releases the accelerator pedal, the on-board
engine computer signals the electronically-controlled automatic transmission to supply
minimum transmission hydraulic line pressure to the clutch packs and to unlock the torque
converter clutch. The torque converter essentially "free wheels" and very
little braking load is transmitted to the clutch packs and transmission output shaft.
These features were programmed into the Ford and Dodge automatics through the ’02
model year to enhance fuel economy and to reduce the pressure against the transmission
seals when no load was anticipated. Banks solved the problem by engineering the SmartLock
to solve these problems for Ford and Dodge automatics.
The SmartLock is a microprocessor-controlled
device that monitors operation of the exhaust brake, engine RPM, vehicle speed, and
the electronic engine control (EEC) processor. It also interfaces with the transmission’s
electronic pressure valve (EPV) and the torque converter lockup solenoid. During engine
braking created by the exhaust brake, the SmartLock locks the torque converter at engine
speeds above 1200 RPM, and computes the appropriate transmission line pressure required
to prevent the clutch packs from slipping under the braking load being generated. It
does this by matching the line pressure to the factory value necessary to prevent slippage
under an identical acceleration load. By not increasing line pressure above the amount
necessary, transmission pump and seal life is enhanced.
The SmartLock disengages
the torque converter clutch below 1200 RPM to prevent lugging down the engine. The Banks
Brake exhaust brake also releases below 15 MPH to eliminate any exhaust restriction
noise and to allow faster throttle/turbocharger response when the accelerator pedal
is next depressed.
The SmartLock is an electronic
transmission management computer that overlays the vehicle’s electronic engine
control processor. Those of you who have read "Why
Add a TransCommand" elsewhere on this site may be wondering if the SmartLock
is the same thing. No, the TransCommand is designed to increase automatic transmission
line pressure for firmer shifts and reduced clutch pack slippage during acceleration.
It works as a "stand alone" transmission enhancement, or in conjunction with
a Banks power system. The SmartLock, by comparison, is designed to increase transmission
line pressure and lock the torque converter during deceleration in conjunction with
an exhaust brake. And yes, the TransCommand and the SmartLock are compatible and both
may be used on the same vehicle. This is because the SmartLock functions only when the
accelerator pedal is fully released, or in the idle position, whereas the TransCommand
has virtually no affect on transmission line pressure in the idle position.
Only the ’01-03 Chevy/GM
6.6L DuraMax offers the DuraMax tow/haul mode switch on its automatic to allow the driver
to keep the torque converter locked at speeds above approximately 20 MPH, and the transmission
line pressure up to keep the clutch packs from slipping. This permits some engine braking
from engine friction – or the installation of an exhaust
brake. Consequently, Duramax pickups don’t need the SmartLock.
Installation of the SmartLock
is easy. The fully potted microprocessor in its extruded aluminum case is mounted out
of sight under the vehicle’s dash. The SmartLock wiring harness is then plugged
into the unit and the EEC. Ford vehicles require extra connections directly to the Ford
transmission. Factory-style connectors are provided to simplify the connection.
Not only does the SmartLock
improve the performance of a Banks exhaust brake, it also extends transmission life
by eliminating the fluid heating that otherwise occurs when the torque converter free-wheels
and the clutch packs slip. The SmartLock is highly recommended to get the most out of
an exhaust brake whenever one is installed on a Ford 7.3L Power Stroke or a Dodge/Cummins
5.9L turbo-diesel with an automatic.
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