MOTORHOME 4-Speed Automatic With Parking Brake
4-SPEED AUTOMATIC equipped motorhomes cannot get better benefit out of a
performance devise than the GEAR VENDORS UNDER/OVERDRIVE™. When the first of the 4-speed
automatic equipped chassis' debuted in 1990, Fleetwood decided that there was a decided performance
advantage to staying with the 3-speed Oshkosh/John Deere chassis and adding the GEAR VENDORS.
So all of the later Fleetwood Limiteds came factory with the GEAR VENDORS. The performance
advantage is because the 4-speed automatics were designed under CAFÉ (Corporate Average Fuel Economy)
legislation for the pickup trucks that carried EPA mileage ratings. Because the whole basis of the
design was fuel economy of an empty pickup truck not performance of a motorhome, the Torque Converter
has a clutch that applies in all gears but 1st. This robs the chassis of the variable ratio and
torque multiplication achieved with the earlier fluid coupling designs in the 3-speeds. So, though
today's engines produce far more power you have no-doubt noticed that they really do not seem to
perform any better when tackling grades and loads.
By installing the GEAR VENDORS you will really wake up the potential of the engine. Plus
you'll be getting this performance through the best means, by attacking the root cause of the
problem which is the limited ratios and torque multiplication of the transmission. The
GEAR VENDORS will give you twice as many forward gears that you can shift to under
any throttle condition. Unlike any other auxiliary transmissions you will be able to go sequentially
to gears right between the existing ratios. Study the Final Drive Ratios and Horsepower &
Torque curves in the Trucks/Towing section for your chassis make. You will have substantial
gains in both Horsepower 50+ and Torque 60+ without modification to the engine or transmission.
Since motorhomes are always loaded aerodynamically as well as laden weight,
the GEAR VENDORS is the best way to reasonable power enhancement. Any modifications you
do directly to the powerplant simply make everything work harder against your continuous load.
A GEAR VENDORS lets you tap into the power of running the engine at the proper rpm with
approximately 1/2 the drop from one gear to the next. Plus, since gears are multipliers of
torque you now have this better running engine getting its torque multiplied to make it easier
on the entire chassis. Because of this, if you have already installed some sort of engine
modifications the GEAR VENDORS will help you get the most from them.
Besides climbing grades, when you are towing you will now run in GEAR VENDORS overdrive
ratio with your factory transmission in direct drive 3rd. This gives you better torque
multiplication and lowers your transmission temperatures by as much as 100 degrees on hot
days - when conditions are perfect for the taller factory gear (cool, no headwind) is the
only time you will use the factory overdrive. Also, since the torque multiplication is higher
in 3rd over there will be fewer times you need to shift out of overdrive so there is some
potential for increased mileage but minimal. The GEAR VENDORS will also not hunt as
some chassis' are prone to (unlocking and locking under slight throttle changes) when in
factory overdrive. For people who care about performance and having things work right, the
GEAR VENDORS is just the right product.
With today's fuel prices you are also concerned with fuel mileage, it is
likely part of the reason you are looking at Gear Vendors. If mileage is the only reason
then fully understand the following. The most cost effective way to improve mileage on a
Class A motorhome is to slow down to 55mph. This is because the aerodynamics (the frontal
area regardless of shape) has a horsepower requirement to drag it through the air. The
common motorhome doubles its wind load every 15mph. This means nearly twice as much
horsepower is required to maintain 70mph as opposed to 55. This also means that the faster
you go the stouter (higher numerical) gearing you need - more rpm.
There are only occasions where double overdrive will save in fuel; You
are not towing a dinghy, you have zero headwind or slight tail wind, you are conservative
on your speed (under 70mph). You can easily determine this by turning on the Gear Vendors
and holding your throttle the same. If the vehicle speeds up at al then you are in a
condition where it's the right gear - if it stays the same then it is not saving you fuel
and in fact could be low enough in rpm to have the Torque Converter of your main
transmission unlock causing unwanted heat and wear - you can see this on the Tach or a
trans temp gauge. For this reason your dealer installs our lockout preventing use of double
overdrive. That way all our customers, towing or not enjoy performance on the grades and
better torque multiplication when needed with 3rd-overdrive. A small percentage of you who
have a good grasp of the aerodynamics and vehicle mechanicals will unplug our lockout and
pick the correct moments to save a little fuel. Gear Vendors recommends our product only
if you want it for the performance - lockout in place. If the only reason you want our
product for is mileage - slow down 10mph instead.
MOTORHOME 4-Speed Automatic W/Parking Brake
GEAR VENDORS, INC. 1717 North Magnolia Avenue, El Cajon, CA 92020
Toll Free 800-999-9555 • Telephone (619) 562-0060 • Fax (619) 562-1186
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