Weekend Wrenchin - HGM Automotive Electronics

Weekend Wrenchin’
Tech
Gearstar 4L60E Install
O
ne of the unsung heroes of any build is the transmission. This is mainly
because most hot rodders don’t understand the black magic going on inside
of them. Too often we just pick up whatever transmission comes along, bolt it in and
hope for the best – not fully understanding what combination of hardware would best
enhance the drivetrain setup in the vehicle at hand. Most all of us have been guilty of
this, but there’s a much smarter alternative – ask the experts. This is just what we did
when deciding on how to get the power from the engine to the wheels in this project.
Getting the right answer was as simple as picking up the phone and calling the
qualified folks at Gearstar Performance Transmissions. The power for our project was
coming from an oddball Chevy 194. They asked all of the important tech specs about
the car, even what the intended driving style would be and used their proven formula
and experience to come up with the right transmission that would provide optimum
performance.
In short order the recommended 4L60E with its custom converter, furnace brazed
with flanged hub and carbon fiber clutch, arrived well packed in a sturdy crate. The
package was complete with a universal fill tube and dipstick, universal transmission
mount, and a special low-profile aluminum converter cover ordered specially for our
low clearance application. The new transmission in the crate was not some stock offthe-shelf unit - Gearstar doesn’t do that – it was built by a qualified technician named
Dave, who was with the project from start to finish, even conducting the Dyno testing.
Because of the testing, the trans comes filled with eight quarts of ATF, plus there are
even an additional three quarts included in the crate for future use. They literally ship
their transmissions ready to install in every way.
The battle-ready crate arrived packed with everything needed for a successful
installation. Even the appearance of the Gearstar transmission doesn’t disappoint.
It looks brand new!
Installation was as
easy as it gets since
we were working
with a bare chassis.
We decided to take advantage of another option offered by Gearstar, the Compushift electronic transmission control system. The programmable unit operates
automatic shifting and torque converter clutch lock up for a wide variety of transmissions including our 4L60E. The real beauty of this unit is that you don’t need a PC or
laptop to program it. The system is delivered with versatile factory set programming, as
well as all of the necessary cable harnesses and throttle position sensor. For additional
programming capability, we opted for the optional liquid crystal display. This made
programming of the transmission’s shift speed and pressure exceedingly simple. You are
able to fine tune with the push of a few buttons.
As for the installation, there’s not much to explain, the transmission of course bolted up like any other once we removed it from its protective travel arrangements. The
car had previously been fitted with a 700R4 so it was a straight bolt-for-bolt swap to the
4L60E, then the simple addition of the universal fill tube and dipstick. Next we followed the instructions included with the Compushift unit for the installation of the
cables so we could then assemble the car.
Once the car was assembled we were ready to complete the installation of the
Compushift assembly, which included the Controller and AccuLink Throttle Position
Sensor (TPS). We gave consideration to the mounting location of the Controller, keeping it away from extreme shock and vibration, high temperature or high input voltage
as well as moisture. Suggested locations were on the floor pan or under a seat with at
least one inch of clearance and away from exhaust heat, and not in the engine compartment as to avoid getting the unit wet. We decided on a spot behind the dashboard,
which is easily accessed through a removable firewall panel.
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The Throttle Position Sensor (TPS)
comes with stainless steel bracketry for several common carburetor types. We had to fabricate
a bracket for use on the unique
Weber sidedraft setup we were
dealing with.
The Compushift unit is ready to go out of the box and has more functions
than you’ll likely need.
Select a safe location for the
Compushift Controller unit;
somewhere free from impact,
exhaust heat and water. Ours is
under the dash.
Calibrating the TPS is simple and
takes less than a minute and is
even easier with the aid of the
optional LCD display.
The transmission harness install is
as easy as plug and play.
The Speed Sensor is also a simple plug
in. Your Transmission Shaft Speed
Sensor (TOSS) will be on the tail snout
for two-wheel drive applications.
The AccuLink TPS is designed to easily mount directly to Edelbrock AFB, Holley
and Rochester carburetors and connect through included stainless steel linkage. A
cable-operated sensor is also available. The sensor is a spring loaded, fully sealed rotary
position potentiometer designed for automotive use. Basically this sensor tells the Controller how heavy your right foot is.
Another neat option available is the Switch-Shift. This feature allows you to manually upshift and downshift the trans via a pair of pushbuttons. With room limited in our
project, we didn’t take advantage of this cool item.
Once everything is installed and secure it’s time to calibrate the TPS. This is done
by following the few easy steps in the instruction manual once the engine has been
warmed up, no longer on fast idle or needing the choke. If there is a problem the
easy to follow diagnosis chart lays out the possible issues as reported by the optional
LCD display.
At this point you are pretty much ready to drive. We tried out the stock settings by
driving around the block, at varying speeds to test the shift points a pressure. Being
installed in a hot rod we opted for upping the shift speed and pressure for a more positive response, but options range from almost unnoticeably smooth to chirp-the-tires
positive shifting. Adjustments can be made directly on the Controller or via the optional
LCD display.
After we got the trans dialed in we started to experiment with the myriad of other
cool functions available via the LCD display like the tachometer, transmission temperature, miles per hour, accelerometer and stopwatch to name a few.
With everything adjusted and many miles on the car the Gearstar transmission and
the Compushift unit have performed flawlessly.
The instruction booklet is clear,
concise and covers the complete
installation and setup.
Once the system is calibrated
and all systems are go, it’s time
to button things up and take her
for a spin.
SOURCE
Gearstar Performance Transmission • 132 N. Howard St. • Akron, OH 44308 • 1-800-633-2353 • www.gearstar.net
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