Precision transmission building

MFactory straight cut close gear set being measured at Whoopee Doo Racing

Not just installation.

At Whoopee Doo Racing there is no such thing as a simple part installation.  Whether it's an all out race build or a simple bearing replacement, every transmission gets the same service.  


  • Transmission is completely torn down and visually inspected
  • Parts are cleaned and dried by hand
  • Parts are visually inspected again
  • Every single part is measured and weighed
  • Case is degreased and inspected
  • Case is media blasted
  • Case is washed clean of blasting debris
  • Case is assembled
  • Differential and mainshaft are mocked up and shimmed with proprietary clearances
  • Mainshaft and countershaft are assembled and clearances checked
  • Any machine work needed for our proprietary clearances is performed
  • Parts are shipped out for various treatments and coatings if selected by customer
  • Parts repeat the cleaning process
  • Differential and gear stacks are finally assembled
  • Transmission is assembled and sealed



MFactory Pro mainshaft in Liberty billt clutch housing being shimmed at Whoopee Doo Racing.

Proprietary Precision.

15 years of building Honda transmissions and countless time spent on R&D has allowed me to find the best clearances to use for different setups and types of racing.  These clearances are precisely and meticulously set on every transmission.  This has allowed my customers to realize a remarkable and uncommonly low failure rate.

Stock B16A/B16B/B18C5 transmission (red) vs the same with 1st, 3/4/5 close gear set and final drive.

Supreme knowledge.

With valuable data and feedback from customers and my own firsthand experience unrivaled by any other transmission expert I can help you choose the best performing transmission components for your particular setup and type(s) of driving.  That can be tailored all the way down to the LSD settings when using a clutch type LSD.


Since every transmission build will require different parts to be replaced on top of any performance upgrades, please contact me so we can discuss the particulars of your build.  Once we confirm the setup I'll be building for you I will send you a customized invoice for the build that can be paid just like you were shopping in my online store.  Since it isn't available in the store, the labor rate for a build is $300.  Any treatments, coatings, machine work or fabrication is not included with the labor rate.


FWD Honda transmissions can be shipped via standard ground.  International shipping is available.  I f you don't have a transmission to send in, I can usually source one.  No cores are required.