Gear Vendors Overdrive Motorhome Dodge, GM & Ford

Gear Vendors Save Gas or Diesel Fuel Extend Motorhome Mileage, Extend Engine Life, Start Saving Money Today!

Does your Motorhome RV need more power to climb hills or tow with heavy loads, plus at the touch of a button taller gearing for cruising down the highway with the lower engine RPM's and improved fuel mileage. Our Gear Vendor overdrive for your Motorhome are available, Our overdrive transmission provides 500 to 600 less RPM's plus 20% increase in fuel economy. You need an auxiliary overdrive transmission capable of gear splitting behind your transmission lower engine RPM means longer engine life. The toughest built best performing auxiliary overdrive transmission you can buy is the Gear Vendor overdrive from Drivetrain Specialist.

See How It Works, Guaranteed Amazing Performance for Your Motorhome

Gears are multipliers of torque and our Ratio Splitting capability allows you to shift to a gear with more mechanical advantage than the next stock gear in automatic transmissions and wide ratio manuals. This also means engine rpm drops about half what it did without the Gear Vendors and so rpm is sustained - higher torque and rpm on shift = more Horsepower. When shifted into overdrive final gear reducing both rpm and torque to reduce the manufacture of HP when steady cruising to improve fuel mileage and decreases wear on your engine. Two-year warranty rated at 30,000 pounds applications for Motorhome, most beneficial when used in commuters, tow vehicles, 5th wheels and Motor homes. Our overdrive kits are very complete and are designed for your specific vehicle, detailed installation instructions are included in kit, and installation is also available. Related to fuel economy, performance, and emissions — Gear Vendors overdrive units include state of the art electronics circuits that keep your vehicle in the optimum performing gear. Whether you are driving a older non-computer controlled vehicle or a late model with all the latest emissions computers our electronics provide the interface to ensure maximum performance and correct rpm without lugging or over revving in the wrong gear. The OE factory programming remains intact and our processor just makes it aware of the actual ratio 1,000 of times per second. In older vacuum or throttle linkage transmissions the stock governor on the output shaft instantly slows down the moment the overdrive shifts and so automatically moves the shift point in any overdrive gear up by the correct 28.6%. So both electronic and non-electronic automatic transmissions gain a group of features including a passing gear or climbing gear that is automatically available without driver intervention and is at the split between 2nd and 3rd where you really want it. Need more information on how to save gas or diesel fuel?

Gear Vendor's Complete Kits Ensure a Smooth Installation in Your Motorhome

Gear Vendor overdrive Kits are Complete with Adapters Our Gear Vendors overdrives are supplies with specific adaptation kits for each model of transmission model, the kits are completed. By supplying specific extension housings to each model/brand transfer case GEAR VENDORS is able to have a better product with gvyoutubesema2008.jpg increased engineering benefit to the final installation. Fact is, when you are in 4X4 there is very little desire to use GearSplitting and overdrive unless you are racing (and we do make the in-between kit for that purpose), it's 2wd where the benefits of overdrive and additional gears are most needed, see YOUTUBE video for more information.  All our kits bolt directly to the rear of the transmission, you can manually control the unit or we suggest you flip switch when leaving city limits sign and turn it off when you get to next city limit sign. No additional crossmembers are required and you retain the factory ground clearance instead of moving the transfer case rearward which puts it at or nearer the middle of the wheelbase where ground clearance is most critical. 

Call our Overdrive Expert Today and get Free Shipping!

You get all the benefits of the GearSplitting performance and overdrive economy (see your appropriate transmission under GM/Dodge/Motorhome 2wd) and the best auxiliary transmission you can buy. Give our overdrive expert a call toll free 800-2161632 he can answer your questions and help you pick correct model for you application, and get free telephone support during installation when you purchase from 

  • You need quality.
  • You'll want reliability.
  • You want performance 22% overdrive.
  • You want better mileage 20% more fuel economy!



Bolt on Perfromance and Economy! 


  • Save Fuel
  • Extend Engine Life
  • Save Money
  • 30,000 lbs Capability



Most Class A’s and Class C’s longer than 30ft have a driveline parking brake.  To confirm, look at the rear of your transmission and you should see a drum for the brake shoes. If your vehicle does not have the transmission mounted park brake then your products will be listed in the GM/Dodge/Motorhome 2-wd section.
3-Speed Automatic   3 Speed Application Chart Dodge, GM & Motorhome Pricing
4-Speed Automatic   4 Speed Application Chart Dodge, GM & Motorhome Pricing

3-SPEED AUTOMATICS gain excellent performance through gears splitting and economy with overdrive. Motorhomes so greatly need overdrive just to cruise at today’s speeds that the product will pay for itself quite rapidly.  The engine and all the engine driven accessories get to slow down 22% when in overdrive.  Not only does this mean less wear but also these components (a/c compressor, alternator,transmission, etc.) will rob less power at the reduced rpm so you are simply more efficient. Mileage improvements in the 20+ percent range are proven in all back to back mileage comparisons done by major magazines.

The Gear Vendors is the finest product for Motorhome performance and is the only performance product ever used as standard equipment by the RV, Truck, and Car manufactures.From Fleetwood Limiteds to GM’s Callaway Corvette, manufacturers have used Gear Vendors because of its performance and engineering reputation as the best in the industry.

Gear Splitting is that ability to give you a gear between each of your forward gears sequentially. Study the Final Drive Ratio chart for your transmission (in the 2-wheel drive section of this catalog) and notice how you will now have 4 underdrive gears, one direct drive gear and one overdrive gear for a total of 6 forward ratios. Notice also how the close ratios keep your engine in the power from one gear to the next.

This is where the trademark UNDER/OVERDRIVE stems from because the Gear Vendors will give you more performance than any underdrive or overdrive on the market. In fact you could purchase both an under-drive and an overdrive by any other manufacturer and still not have the performance of a Gear Vendors. The only thing an underdrive could do is get you a gear below first, which Gear Vendors cannot, but you gladly trade that for all the performance and engineering of a Gear Vendors.

All other underdrive or overdrives on the market are simply Dual Ranges. This means they are intended to just give you three lower gears or three taller gears but yous till have the same space between each gear you have now. This is because all competing units are small manual transmissions whereas the Gear Vendors is designed like your automatic. With other products you could actually go slower than you do now. The Gear Vendors is the only product actually intended to shift through the gears when you need power, under any throttle condition, including full throttle.

Now you will always have the right gear for power and economy. Plus, the Gear Vendors gives you 727mgb_large.jpgmany automatic features with our AUTODRIVEN control system,which is standard and turns the overdrive on and off automatically just like your vehicle came factory equipped with the system.

Read also the section concerning your transmission in the 2-wheel drive portion ofthis catalog and study the Horsepower and Torque curves in that section as well.Then, simply call us and we will arrange an installation at your local dealer oranswer any questions you have. There is simply no good reason not to own a Gear Vendors in these vehicles.

4-SPEED AUTOMATIC equipped motorhomes cannot get better benefit out of a performance device 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 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 on grades and loads.4l80b_large.jpg


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 transmission 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 2-Wheel Drive 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 power plant 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 modification the Gear Vendors will help you get the most from it.e40db_large.jpg

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 much better torque multiplication and lowers your transmission temperatures by as much as 100 degrees on hot days. Also, since the torque multiplication is higher there will be fewer times you need to shift out of overdrive so there is some potential for increased mileage and certainly no cost in mileage. Some chassis’ are equipped with 5.13 or higher rear ends. These chassis’ can make use of double overdrive when conditions are right for even more mileage benefit. The Gear Vendors will also not hunt as some chassis’ are prone to (unlocking and locking under slight throttle changes) when in factory overdrive, as the UNDER/OVERDRIVE communicates with the vehicle control processor so that you get consistent performance.

For people who care about performance and having things work right, the Gear Vendors is just the right product. (you will also find useful information under your brand and transmission in the 2-wheel drive section.)


Gear Vendors Overdrive Motorhome Dodge, GM & Ford Products




Check out the unlimited horsepower warranty and money backguarantee and the simple installation in the dimensions section.

Motorhome 3 Speed Automatic Application Guide

Part Number




3D0475 GM Automatic 3-Speed 475B with Hand Park Brake. Replaces tailhousing. Park brake moved to back of 2-speed.  See the kit. GM P30 chassis w/manual cable park brake.
3D0476 GM Automatic 3-Speed 475B with Foot Brake Hydraulic. Replaces tailhousing. Park brake moved to back of 2-speed.  See the kit. GM P30 chassis w/hydraulic park brake.
3D0061 Ford C6 3-Speed Auto Trans with Driveline Park Brake. Replaces tailhousing. Park brake moved to back of 2-speed.  See the kit. Motorhome John Deere/Oshkosh chassis (15 Tooth Drive Gear).
3D0062  Ford C6 3-Speed Auto Trans with Driveline Park Brake. Replaces tailhousing. Park brake moved to back of 2-speed.   See the kit. Motorhome John Deere/Oshkosh chassis (14 Tooth Drive Gear). 
3D0064 Ford C-6 3-speed Automatic Transmission with Driveline Park Brake. Replaces 7" tailhousing. Replace output shaft with GV shaft (incl). Park brake moved to back of 2-speed.  See the kit. 88-newer Foretravel and Beachcraft motorhome with Ford rear engine. Factory installs At GEAR VENDORS ONLY.
3D0730 Dodge TF 727 3 Speed Automatic transmission. Kit includes much stronger Bendix-brake like Allison and Motorhome Replaces 12 tail housing. New Bendix brake replaces stock brake and is moved to the back of the 2 speed.    See the kit. 1970 newer Dodge class A motorhome with driveline parking brake
Motorhome 4 Speed Automatic Application Guide

Part Number




3D4L80  GM  Automatic 4-Speed 4L80EB with Hydraulic Park Brake. Replaces tailhousing 91-93 P30 chassis with auto park brake. 
3D4L81 GM 4L80EB 4 Speed with Cable Park Brake. Replaces Tail housing, see the kit. 1991-1993 P30 chassis w/automatic park brake
3D4L82 GM 4L80 4 Speed Replaces Tail housing, see the kit. 1994-1995 P30 chassis w/auto hydraulic park brake, requires GM speed buffer included
3D4L83 GM 4L80 4 Speed Replaces Tail housing, see the kit. 1994-1995 P30 chassis w/manual park brake, requires GM speed buffer included
3D4L83 GM 4L80 4 Speed Replaces Tail housing, see the kit. 1996 and newer with auto brake
3D4L84  Automatic 4-Speed 4L80EB with Hydraulic Park Brake. Replaces tailhousing. 96 and newer P30 chassis with auto park brake.
Requires GM speed buffer (incl), provide axle ratio and tire size when ordering. 
3D4L85  Automatic 4-Speed 4L80EB with Mechanical Park Brake, Replaces tailhousing, 96 and newer GM P30 chassis with a manual cable park brake
Requires axle ratio and tire size when ordering.
3D0E41 Ford Motorhome E4ODB 4R100B 4 Speed Replaces Tail housing, see the kit. 1988 and newer Motorhome chassis is class A motorhome with park brake
3D0E42 Ford Motorhome E4ODB 4R100B 4 Speed Replaces Tail housing, see the kit. 1993-1999 F450 Super Duty, 1998 and newer class A&C motohomes w/V10 gas
3D4R101 Ford Motorhome E4ODB 4R100B 4 Speed Replaces Tail housing, see the kit. 1999-2000 V10, confirm 10th digit in VIN is "x or y"
3D4R102 Ford Motorhome E4ODB 4R100B 4 Speed Replaces Tail housing, see the kit. 99-00 V10, confirm 10th digit of VIN is X or Y, and if vehicle has 4-wheel anti-lock brakes.
We have included a frequently ask questions section that may answer some of your questions, don't see answers you need, just give us a call we will be happy to review your application with you. The following links provide specific application information, performance data that you can expect and the price data for your specific vehicle.