About Gearbox Express

Gearbox Express, Mukwonago, WI

Gearboxes are all we do

Gearbox Express is the only independent company in North America solely focused on providing down-tower, wind gearbox remanufacturing solutions.
We focus strictly on gearboxes, and we know how to keep them running.

Gearbox Express was founded by gearbox guys who grew up in the industry and have years of experience with both gearing and bearings. Founded in 2011, Gearbox Express has exceeded its own expectations for growth thanks to its unwavering commitment to customer service and to innovative solutions that are better than anyone else in the wind-energy industry.

At Gearbox Express, we believe in proactive gearbox life-cycle management. It is our mission to get the maximum life out of your assets. And we back our work with a three-year, no-risk, warranty that is upgradeable to five.

Our new facility

We have exceeded growth projections so aggressively, it was necessary to build a larger facility in order to meet demand, increase efficiency, and maintain service standards. Our new 80,000 square-foot facility in Mukwonago’s new industrial park is twice the size of our original location, offering deeper and broader technological advances in our equipment.


  • 100% new construction
    – All precast and fully climate controlled
  • 80,000-square feet for phase 1
  • 10-acre site permits phase 2 expansion
  • Dedicated bays
    – Receiving / Disassembly, Two 30T cranes
    – Assembly, Two 30T cranes
    – Testing / Shipping, One 30T crane, One 60T crane
  • Two 3.1MW test stands
  • In house super finishing capability
  • Dedicated mainshaft assembly
  • Expansive parts inventory for uptower repair providers
  • Storage and maintenance
  • GBX School

Gearbox Express 60-Ton Crane

At the heart of the GBX operation is its 3.1 MW (4,000 hp) regenerative test stand that mimics real-life, often variable, wind conditions. The Gearbox Express technical team tests each and every gearbox to guarantee it will run properly. The technology used for and the data-analysis output from our test stand is pioneering and predictive.

Our products

Many downtower remanufacturing upgrades now available for uptower maintenance
Lube system GBXchange (including heat exchanger and pump)

  • Hose Kits
  • HS Pinion and IMS Gear Assembly Kits
  • HSS / IMS Bearing Kits
  • Lube Pump Motor Flip Kit
  • WaterLok
  • GBXtreme Filtration

Our focus on lubrication

Proper lubrication is essential for gearbox function and is an easy way to extend gearbox life. At Gearbox Express, we

  • Offer enhanced filtration
  • Use an upgraded delivery system
  • Conduct regular oil sampling
  • Provide water concentration monitoring and remove system
  • Monitor lubrication cleanliness