Cotta manufactures a transfer case and top mast drive for a customer that uses the gearboxes in water well drill rigs.  The top mast is a small gearbox that goes into the mast of the drill rig, and is responsible for turning the pipe that drills the hole in the ground.  The transfer case is used to drive the truck and all its accessories.

Below is a picture top mast gearboxes in assembly:

Top Mast Gearbox in Assembly

Top Mast Gearbox Specifications:

Ratio:  2.50 to 1 Reduction

Max Input Speed:  600 RPM

Max Output Torque:  12000 Ft-Lb

Max Pull Out on Output Shaft:  30,000 Lbs

Approximate Weight:  600 lbs

Below is a picture of the transfer case prior to paint:

Transfer Case Before Paint

Transfer Case Specifications:


  • 1:1 Input to Output
  • 1:1.2 Input to Pump Pad

Max Speed:  3000 RPM

Max Cont Torque Thru Gears:  1900 FT-Lb

Max Cont Torque Top Shaft:  12,500 FT-LB

Yield Torque Top Shaft:  17000 Ft-LB

Max Power:  700 HP

Approximate Weight:  1160 LB



Gearbox efficiency is a measure of the power transmitted by a gearbox, or put another way, the power lost in a gearbox.  The difference between input and output power (loss) is due primarily to gear, bearing, and seal friction.  However, other factors contribute to losses, such as gear windage and the power to operate a lube pump if the gearbox is so equipped.

The magnitude of loss in a given gearbox depends on many factors, some of which are listed below:

  • Number of gears
  • Gear type (helical, worm, spur, etc.)
  • Gear quality level
  • Seal fits
  • Bearing type
  • Lubricant type and level
  • Speeds
  • Loads

Calculation of the exact losses is difficult and often turns out to be inaccurate. In fact, two apparently identical gearboxes may have slightly different efficiencies due to tolerances, fits, assembly practices, etc. For this reason, most gearbox manufacturers normally have a “rule of thumb” for estimating losses. The “rule” a given manufacturer establishes is usually based upon a combination of their engineering calculations, testing, and field experience.

Cotta’s rule of thumb for losses is 2% of the rated input HP  per loaded gear mesh – “worst case”. For example, an input/idler/output gear set would be estimated at 96% efficient. The reason for this is that there are two loaded meshes, the input-to-idler mesh, and the idler-to-output mesh.

Sample calculation is as follows:

Prime mover HP = 400

Loaded meshes = 2

Loss = 4% (2% * 2 meshes)

Loss = .04 x 400 – 16 HP

16 HP x 2542 = 40.672 Btu/hr

TRAP: Multiple speed gearboxes may have only one loaded mesh; however, there may be several unloaded meshes spinning – sometimes at high speed.  This will cause some heat even though no power is being transmitted. Multiple speed transmissions are a special case, and should be discussed with Cotta Engineering.

The losses in a gearbox must be accounted for both in prime mover size and heat rejection. That is, the prime mover must be “oversized” enough to make up the frictional losses. In our example, a maximum of 384 HP can be expected at the load. If 400  HP is required at the load, then the prime mover must deliver 416 HP to the gearbox (400 HP + 16 HP = 416 HP).

Losses in a gearbox manifest as heat and cause the lubricant temperature to rise. Depending upon the design, the gearbox case may dissipate this heat and keep temperatures at a reasonable level. However, as transmitted HP increases, external cooling becomes necessary. The HP losses calculated in our example represents the heat that must be rejected. Heat exchanges should be sized for those values. Cotta application engineers will recommend a heat exchanger if the application indicates over temperature is possible.

If you have questions regarding efficiency, contact Cotta at 608-368-5600, or email .

Cotta had a retirement celebration for Sales Manager, Paul Bachleda, this past week.   Paul had been employed by Cotta for a combined 17 years, with his most recent position having started back in 2017.  Paul first joined Cotta as an Application Engineer, and worked for 12 years prior to taking a position as an Account Manager in Oilfield Production for ZF.  Throughout Paul’s career he also worked for White Farm Equipment, JI Case, Koyo Bearings, and Fabco.  In addition to holding positions as Application Engineer and Account Manager at those companies, Paul also was involved with prototype assembly and engine dynamometers.  Paul’s extensive knowledge working with gearbox and other drivetrain components for industrial, farm, construction, oilfield, and off highway equipment has proven to be of great value to Cotta and their customers over the years.

We wish Paul the best in his retirement, and know he will be doing what he loves….farming and fixing cars.


Cotta Transmission has a niche in the high-speed gearbox market, offering custom solutions when off-the-shelf products just aren’t a fit.  Companies continue to turn to Cotta’s engineering department for unique prototype solutions, many of which are being used in test stands to help validate the customer’s developing technology.

Cotta manufactured this speed reducer that is being used in an aerospace test stand application.  See specifications below:

  • Ratio:  1.719 : 1
  • Maximum Shaft Speed:  29,000 RPM
  • Maximum High Speed Shaft Power:  445 HP
  • Maximum Accel/Decel Rate:  2000 RPM/s on High Speed Shaft
  • Approximate Weight:  270 LBS
  • Total Inertia:  .06868 LB-IN – S^2
  • Referred to High Speed Shaft

Cotta provides you with the optimum gearbox design for your application.  Provide us with as much information as you have available by clicking here.

Cotta Transmission gearboxes are personally crafted to meet your requirements, and are some of the most reliable, durable, and powerful products available in the industry. Cotta works with each customer to discover their specific needs, uncover the power issue causing problems, and designs the best possible product to overcome the challenges that the application presents.

For example, Cotta designed a top mast drive from the ground up specifically for a customer’s blast hole drilling application. The bearing arrangement on the output shaft was designed to have as much downward force as upward force on the bearings, which is a very desirable feature for a blast hole top mast drive. A typical top head will have the bearing configuration on just one side so that all of the steel can be held up in the air with the appropriate amount of pressure on the bit while drilling. Cotta’s solution was designed with our customer to meet their unique requirements for pushing down or pulling up. The greater down force gives the end user the ability to drill the blast holes faster. Cotta’s custom top mast drive has proven to be a strong and reliable product for the customer for over 30 years.

Blast Hole Drilling Top Mast Drive

Cotta has over 2,000 existing product designs available, and an experienced engineering team that can take any new transmission application from concept to delivery at our production facility in Beloit, WI.

Cotta manufactured these direct mount transfer cases that will be directly mounted to the back of an Allison Transmission, and will be used in oilfield workover rigs.  These units have been extremely reliable and durable in harsh conditions.   This model is a three shaft transfer case designed to direct mount via flange to Allison HD4000 Series transmissions.  Three output stations are available for fitment with various options, such as drive-line yokes, companion flanges, drive shafts, PTO disconnects, axle disconnects, pump pads, clutches, and similar ancillary equipment.


Normal Application Power:  600 HP

Input Torque Capacity:

  • 1500 lb-ft. continuous through gears
  • 12500 lb-ft continuous through PTO shaft
  • 17500 lb-ft momentary through PTO shaft

Max Input Speed:  3000 RPM

Ratio:  1:1 input to output

Center Distance:  19 inches input to output

Rotation:  Outputs rotate same direction as input

Lubrication:  Internal reservoir. Lube pump furnished

Shifting:  Disconnects are air shift.  Mechanical shift options available

Output Shaft Size:  2.75-10 straight side spline

Common Options:  SAE and ISO yokes and flanges, disconnects, pump pads, clutches, stub shaft

Weight:  Approximately 1400 lbs.


To learn more about Cotta Transfer cases, call 608-368-5600, or email .




Customers have access to the best in transmission technology expertise when Cotta is their chosen source.  Our engineers are a true extension of your company.  We have experience working with hundreds of companies and thousands of gearbox designs, our team of engineers will listen to your needs and share ideas, fulfilling your requirements to the best of our capabilities.  We are ISO 9001:2015 Certified as well, ensuring the highest quality practices in our product design and engineering, our test and measurement equipment, and other internal throughout processes. Whether you need a standard, modified-standard or completely new design, Cotta is ready to get to work.

Cotta has 2,000+ existing product designs available, plus our experienced engineers and craftsman can take virtually any transmission application from concept to delivery at our Beloit, Wisconsin production facility.  Our engineers and designers work with customers to develop solutions and then deliver drawings in virtually any CAD format to drop into the customer’s own design.

These are just some reasons why Cotta has been in business for over a century.

Quality Gearing


Cotta’s long tradition of manufacturing the highest quality gearboxes, made in the USA for over 100 years, is exemplified in our extensive line of heavy-duty performance line of products.  Cotta recently manufactured these industrial speed increasing gearboxes for a customer who had the same model gearbox operating in the field for over 30 years.  Cotta is supplying the customer with 2 new units that will be used in an industrial application.

See specifications below:

Ratio:  1 to 2.67 Overspeed

Rotation: Anti-Engine

Max Output Speed:  5800 RPM

Approximate Weight:  1000 lbs.


LEARN MORE: Cotta Speed Increasers

Speed Increasing Gearbox

The speed of development of electric vehicle drivetrains and components has brought new testing challenges to the test equipment market.  One of those challenges includes finding new, high-speed test equipment for component and drivetrain testing.  Cotta has supplied some of the world’s leading electric vehicle & drivetrain manufacturers with high performance gearboxes.  Cotta gearboxes are designed for years of high-cycle testing up to 90,000+ RPM.  With many more hybrid and electric vehicles coming to the automobile market, a significant portion of energy consumption will be electricity use. A number of Cotta customers have a long history of testing these types of vehicles to understand the energy flows and the impact that certain aspects, such as regenerative braking and HVAC, have on the electrical energy consumed both from the vehicle battery and the electricity grid. Testing helps improve the energy efficiency of vehicles to reduce the vehicle’s operating costs, and meet regulatory requirements of a low-carbon economy.

Several Cotta customers offer test system solutions for measuring electric vehicle energy efficiency. Below are some typical electrification applications where our broad line of high-speed gearboxes are used:

  • High-Speed Electric Motor Test Systems
  • Electric Axle Driveline Test Systems
  • Electric Accessory Testing

Since the 1960’s, Cotta has been designing and manufacturing a diverse line of high-speed customized gearboxes to meet the specified needs of customers.  Cotta’s high-speed gearboxes are used by major automotive and component manufacturers for both R&D, and production test stands.  Cotta gearboxes are designed and built to last, with some of the early units still operating in the field today.   One example, is a customer that uses a Cotta gearbox in one of their in-house stands. The gearbox has  operated for over 25 years without a major breakdown.  The customer has specific requirements for stringent applications, and over the years Cotta has always been quick to respond to meet the customer’s needs.

LEARN MORE: Cotta’s High-Speed Gearboxes

Cotta supplies a pump drive to a customer that was in need of units that would be used for a hydraulic crowd in a mining shovel application.   Mining shovels are used to excavate large quantities of soil and rock fragments in surface or strip mining operations.  Classic mining shovels were designed with a winch and cable that operates the bucket up.  The problem with that type of design, is that the cables run over the pulleys in the same spot every day. After so many hours of use, the cables wear out, which results in the machine having to be shut down for at least a day to get the cables restrung. Cotta’s engineering team designed a pump drive for the application, and by using a hydraulic cylinder this eliminated the need for a cable drive.  This technology has saved the customer time and money, as it allows the operators to run the machines for a number of years before service work is required, versus being down once a month to restring the cables.

Gearbox Specifications:

  • Ratio:  1.0 to 1.0
  • Max Torque:  4920 Ft-Lb
  • Max Speed:  1100 RPM
  • Max Power:  1030 HP
  • Max Power Per Pad:  257 HP
  • Approximate Weight:  2800 LB

Pump Drive Ready to Ship

Cotta’s high-capacity pump drives are constructed with top quality materials and precision machining to offer you with the competitive edge you need to meet your most demanding pumping challenges. Contact Cotta for more information by emailing, or calling 608-368-5600.