History
In 1982 when the decision was made to take an analytical look at the
RV'ers towing problems, it didn't take long to realize what the industry
really needed was a 2-speed axle. And quite honestly, that still holds
true today. But it soon became apparent that with all the different
vehicle applications and rear axle combinations required, plus the difficulty
of this type of installation, the idea would be both impractical and
outrageously expensive.
But what
about a 2-speed that didn't have to be installed in the rear axle? This
would allow one basic gear box, with the various applications handled
with relatively inexpensive adapters. And now, the installation could
be handled by almost any knowledgeable service center. The results?
the birth of the patented Dual Range Auxiliary Transmission.
Why A
2-Speed?
Since the late 70's the large majority of RV towing has been done with
1/2 ton - 1 ton truck type vehicles; most are equipped with automatic
transmissions. With towing weights as high as 12,000-15,000 lbs. there
is no way, especially with the horsepower available, to have enough
gearing for low speed pulling and still be able to cruise economically
at interstate speeds. By selecting the proper Dual Range to complement
your existing gear ratios, you can in fact enjoy both. Low speed
power and high speed economy.
How To
Select Your Dual Range
If you have plenty of low speed power and you need high speed help (this
is becoming increasingly rare), then you would simply add the Dual Range
with the higher gearing (overdrive). If you are OK on the road at high
speeds, but just don't have enough power when fully loaded then you
need to add the underdrive ratios. Our technical people can help you
make the decision for the best possible choice. With the proper Dual
Range added to your vehicle you will now have both low speed and high
speed help available at your finger tip.
How To
Use The Dual Range
It's really very simple. At the flip of a switch, you can select a high
speed ratio for highway cruising or solo driving, or you can select
a low range for highway towing, city driving, or mountain terrain. Shifting
back and forth from high range to low range can be done at any speed
(shift-on-the-fly). Of course, if you are parking your trailer for the
season, you may choose to leave the Dual Range in the high speed mode
until you are towing again.

Factory
Overdrives
Within the last few years, the automotive factories have begun to offer
overdrive transmissions as standard equipment. While they are some help
to the people using their trucks like Buicks, they are completely useless
for towing. In fact, most factories prohibit towing in the overdrive
position. But, by adding the low speed version of the Dual Range (underdrive),
the factory transmission becomes a real pleasure to use. Not only do
you gain the pulling power so useful for towing, you're actually able
to use that power in the factory overdrive mode! No one else can offer
that feature in the RV industry.
Applications
Available
Class 'A' Motor Homes; the very popular Class 'C' version of the same;
Fifth Wheel and Travel Trailers; Three and Four Speed Automatics; Four,
Five, and Six Speed Standard Transmissions: We've Got Them All! And
we are adding new popular applications as soon as they become part of
the towing world.