9420 Stony Island Ave
Chicago, IL 60617
Phone: (773) 375-4900
United States Gear Corporation is a family owned and managed gear and power transmission component manufacturer in Chicago, serving a worldwide customer base.
U.S. Gear's current products include differential and transmission components, everything from hot rods to heavy duty trucks. Our highly advanced gears can be found in some of the world's fastest race cars.
Our subsidiary, Heat Treat Corporation, operates as a commercial heat treater as well as the heat treat department of U.S. Gear. We use computer-controlled furnaces throughout the facility, allowing extremely accurate process control, resulting in certifications of competence from Caterpillar, IBM, Ford, Dana and the aerospace industry.
Dual Range® Auxiliary Transmissions
Changes in the Towing Industry
Over the past decade, automotive manufacturers have incorporated major power and performance enhancements to both gasoline, and especially diesel powered vehicles. In fact, many of these specialty engines have an amazing amount of torque under the hood. Some vehicles on the other hand, are designed to simply provide good economic value. From the factory, your vehicle should be equipped to give you either the power you are looking for, or the economy you need. In the real world however, it's not that simple. There are times when you really need the extra power; like when pulling heavy loads. Then there are other times when you really need the fuel economy; like when cruising at high speed with no loads. It is for this reason that US Gear offers TWO DIFFERENT AUXILIARY TRANSMISSIONS; AN UNDERDRIVE UNIT OR AN OVERDRIVE UNIT, MADE IN AMERICA. No other manufacturer in the industry can make that claim.
Why Two Different Units?
From the factory, your vehicle comes with only one rear-end ratio. So what happens when sometimes you're heavy and in need of those extra low end gears to get you up and moving while other times you're light and need the higher gears to get you moving faster and more economically? The fact is that one extremely low gear ratio does not offer the gear selection necessary to provide both low speed power and high speed economy. And what about the times when you're at high speed and suddenly need just a little more power, but don't have enough gears to comfortably get any. Conversely, if you are at low speed and suddenly need to be moving quicker, there's simply no way to make it happen. To keep the engine in its maximum power range, Dual Range offers twice the number of different gears to easily move you to the closest gear necessary for your immediate needs...all with a push of a button.
The overdrive unit gives you twice as many higher gear ratios than you originally had for more pulling performance, while the underdrive gives you twice as many lower gears for that extra power you need to get your weight moving easier with less throttle. Whichever unit you choose, you will improve economy, and decrease wear and tear on the engine. So which one is right for you? Let's take a look at the different issues specific to motorhomes, trucks and vans.
Specific Truck and Van Issues
Trucks and vans that pull trailers, whether gas or diesel, automatic or stick, are distinctly different from motorhomes, because their loads can be dropped. This means that sometimes you'll be heavy while other times you'll be light. And because your engine produces its best power in a narrow rpm range, you will need the flexibility of numerous gear ratios to keep it running in the "sweet spot". If you own a newer model truck with an automatic transmission, chances are it came standard with an overdrive. But if you are towing really heavy loads, the OE overdrive may be too high even with the tremendous horsepower and torque produced by the engine. Even the original equipment manufacturers tell their customers NOT to pull heavy loads with it. Under this set of circumstances, you will need to add the Dual range to either replace, or lower the factory overdrive ratio to give you the power and economy you are looking for.
By selecting the proper Dual Range unit to complement your existing gear ratios, you can finally enjoy both low speed power and high speed economy. Our tech department can help you decide what is right for your set of circumstances.
Specific Motorhome Issues
Gasoline powered motorhomes with automatic transmissions are extremely heavy and continuously get heavier as amenities such as slide out rooms, washers, dryers and even the family sedan are added. They already come equipped with an overdrive providing the needed high gear ratio, but don't have low gear ratios for climbing the hills quicker and with less throttle; not to mention engine retarding for coming down the hill. Throw in the fact that you can now drive faster due to speed limit increases, and you've really got some complications. You obviously need a Dual Range underdrive unit. And by adding this low range unit, 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.
How To Use The Dual Range
Nothing could be easier! An electronic control module mounts directly to the gear shift lever and permits precise control of the Dual Range Auxiliary Transmission. While the unit is electronically controlled, you will hear it shift mechanically as do big over-the-road commercial trucks. And it's this simple; keep the unit in the low range position when you are driving in mountainous regions or when heavily loaded, and shift to high when you're cruising on the interstates. Or, you can shift the Dual Range as you're shifting the primary transmission to split your existing ratios.
And the Dual Range Is a Real Work Horse
From the very beginning, the Dual Range was designed for towing extremely heavy loads. With a GVCW rating of 35,000 lbs and a torque capacity of 2000 ft lbs, the Dual Range has the strongest guts in the industry. It was specifically designed to use in either 2-wheel or 4-wheel drive, forward or reverse, both uphill or downhill compression braking, and at any speed. There simply is no limit to how and when to use the Dual Range. Again, no other auxiliary transmission manufacturer can make that claim.
Pick-ups, vans, cab-chassis, class C or the very popular class A motorhomes, two-wheel or 4-wheel drive, We've Got Them All! We are adding popular new applications as soon as they become part of the towing world, so stay tuned!
Call our technical support department; tell them what you have and what or where you feel you need improvement. Chances are, they already have a solution.
|GM 2WD Automatics|
|3-spd. (T475B)||P-30 Chassis w/ transmission parking brake||170-28025B||170-28080B||D||80-80025B|
|4-spd. (T4L80E-B)||'91-'95 P-30 chassis w/ Transmission Parking Brake||170-28025BM||N/A||C||80-80035B|
|4-spd. (T4L80E-B)||'96-'99 P-30 chassis w/ Transmission Parking Brake
(4 wheel ABS)
|4-spd. (T4L80E-BH)||'91-'95 P-30 chassis w/ Transmission Parking Brake (Hydraulic Assist)||170-28025BM||N/A||E||80-80035BH|
|4-spd. (T4L80E-BH)||'96-'99 P-30 chassis w/ Transmission Parking Brake (Hydraulic Assist) (4 wheel ABS)||170-28025BM||N/A||E||80-80035BHC|
|GM 4WD Automatics|
|3-spd. (T400)||Pick-up/Suburban w/ NP208 or BW1370, '80-'87 big block engines||140-28025||140-28080||C||80-80046|
|3-spd. (T400)||Pick-up/Suburban w/ torsion bar w/ NP241 & BW4110 big block engines '88-'90||140-28025||140-28080||D||80-80048|
|4-spd. (4L80E)||Pick-up/Suburban w/ torsion bar w/ NP241 & BW4110 big block engines '91-'95||140-28025||140-28080||D||80-80048M|
|4-spd. (700R4)||Pick-up/Suburban w/ NP208 or BW1370 '80-'87 small block engines||140-28725||N/A||C||80-80046|
|4-spd. (700R4/4L60E)||Pick-up/Suburban w/ NP241. '88-'95 small block engines||140-28725||140-28780||D||80-80049|
|GM 4WD Manuals|
|4-spd. (SM465)||Pick-ups, Crew-Cabs, & Suburbans w/ NP208 or BW1370 '80-'87||140-28025||140-28080||C||80-80045|
|Note: All 4WD Pick-ups with Standard Cabs will require fuel tank modifications.|
|Dodge 4WD Automatics|
|4 spd. (518)||Pick-ups w/ Cummins diesel and gas engine, '94 & up (23 spline output only)||140-68325**||140-68380**||
|Dodge 4WD Manuals|
|5-spd. (NV4500)||Pick-ups w/ Cummins diesel and gas engine, '94 & up||140-68925**||140-68980**||
|6-spd. (NV5600)||Pick-ups w/ Cummins diesel engine (29 spline only)||140-68925**||140-68980**||
|** These applications require fuel tank modification on standard cab trucks or trucks with short beds. 4WD units are mounted between the primary transmission & transfer case.|
|Ford 2WD Automatics|
|4-spd. (E4OD/4R100)||Pre-'99 F450 Super-Duty Cab-Chassis w/ transmission parking brake||140-48025**||140-48080**||C||80-80036B|
|4-spd. (E4OD/4R100)||Ford Chassis Super Duty Class A & C Motorhomes w/ transmission parking brake||140-48025**||140-48080**||C||80-80181|
|Ford 2WD Manuals|
|5-spd. (ZF5-B)||Pre-'99 F450 Super-Duty Cab-Chassis w/ transmission parking brake||140-48025||140-48080||C||80-80180|
|** Installations on '92 or newer Diesel and '93 or newer Gasoline vehicles or any E4OD that has
been upgraded, will require our Speed Processor PN 84-80006 for proper operation. (This includes all vehicles with the 4R100 transmission.)
|Ford 4WD Automatics|
|3-spd. (C6)||All trucks w/ NP208 or BW1345/1356 transfer case.||140-48025||140-48080||C||80-80060|
|4-spd. (E4OD/4R100)||Same as above (not for 6.0L diesel)||140-48025**||140-48080**||C||80-80060|
|Ford 4WD Manuals|
|4-spd. (T18-19)||Same as above||140-48025||140-48080||C||80-80065|
|5-spd. (ZF5)||Same as above||140-48025||140-48080||C||80-80065|
|6-spd. (ZF6)||Same as above (not for 6.0L diesel)||140-48425||140-48480||C||80-80065|
|4WD units are mounted between the primary transmission & transfer case; installation on Ford single cab 4x4 vehicles with dual fuel tanks will require modification of front tank. Also, Ford Crew-Cab models will require modification to floor pan to make the necessary clearance for the Dual Range and the new location of the transfer case. This can normally be accomplished by pushing up on the floor. Contact your dealer for more details on your application.
** Installations on 92 or newer Diesel and 93 or newer Gasoline vehicles or any E4OD that has been upgraded, will require our Speed Processor PN 84-80006 for proper operation. (This includes all vehicles with the 4R100 transmission.)
If I install the Dual Range, will it void my vehicle warranty?
No, the addition of the Dual Range doesn’t void your vehicle warranty. Automotive manufacturers such as Dodge, General Motors, Ford, Freightliner, and Spartan have publicized the fact that the addition of aftermarket products does not void their warranties. There has been a lot of confusion about this issue, but federal law actually prohibits manufacturers from voiding warranties based on the addition of aftermarket parts unless they can prove that the aftermarket item caused a failure in the vehicle.
What is the warranty on the U.S. Gear Dual Range?
U.S. Gear warrants the product from defect for one full year, with unlimited mileage, from the date of purchase. The warranty covers 100% of parts, 100% of labor, and all freight charges. A copy of the written warranty is included with each product.
What is the ratio of the Dual Range?
The Dual Range is available in two different models: Direct and 20% Overdrive or Direct and 20% Underdrive. The 20% overdrive ratio is .80 and the 20% underdrive ratio is 1.25.
How does the Dual Range work?
The Dual Range works exactly like an electric 2-speed axle commonly found in commercial trucks. The Dual Range bolts directly to the back of your factory transmission giving you the equivalent of two axle ratios or twice the transmission ratios (gear splitting). 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).
How does the Dual Range compare to the competition?
The U.S. Gear Dual Range is the only American-made, electric-operated auxiliary transmission in the industry. It has the heaviest GVCW rating (35,000#) and is the only auxiliary transmission available as either overdrive or underdrive. The Dual Range is also priced $500-$800 less than the competitors. The Dual Range is the only unit that has no limitations on how it is used. It can be used in forward or reverse, 2 or 4 wheel drive, uphill and downhill. No other auxiliary transmission manufacturer can say that.
What vehicles will it fit?
The Dual range will fit all Dodge, GM, and Ford full-size pick-ups, vans, Suburbans, class C and class A motorhomes with automatic or manual transmissions, 2 or 4 wheel drive.
Is installation difficult?
Installation of the Dual Range always requires shortening and balancing of the drive shaft. In most applications, this is the only modification required; however’ on occasion modifications may be necessary to the exhaust system, floor pan, and in some 4WD applications, modification to the fuel tank. The balance of the installation is a simple bolt-on and wiring the driver control that is supplied in each kit.
What kind of fluid does the Dual Range use?
The unit uses one quart of 80-90 weight gear lube. A good synthetic equivalent is acceptable, also. We recommend changing the gear lube every year or 20,000 miles.
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