Gearstar Performance

Custom Transmission Build Team

  • torque converter matching
  • dyno testing
  • transmission installs
  • GM performance automatics
  • Ford performance automatics
  • Mopar performance automatics




Gearstar Performance Transmissions has been hand-building high-performance automatics in Akron, Ohio since 1996. Every unit is assembled start to finish by one builder, matched to the customer's engine, gearing and intended use, then dyno-tested before it ships. The build team writes here about transmission specs, install procedures, torque converter matching and what actually holds up behind real power.

6 Automotive Things to Be Grateful for This Thanksgiving and Beyond

6 Automotive Things to Be Grateful for This Thanksgiving and Beyond

Gearstar Performance 6 minute read

It's Thanksgiving month again, and time to be eternally grateful for everything life has thrown our way - the good, the bad, the ugly, and we survived...

4R70W Performance Fundamentals Guide

4R70W Performance Fundamentals Guide

Gearstar Performance 5 minute read

The 4R70W is a revised version of the famous Ford's long-running 4-speed AOD (automatic overdrive) transmission that appeared in the '80s. Experts...

6L80E Transmission Specs and Identification

6L80E Transmission Specs and Identification

Gearstar Performance 5 minute read

The arrival of 6L80E transmissions – or Hydra-Matic 6L80 transmissions – on the automotive scene in 2006 showcased the considerable design change of the...

Rebuilding a Faster, Better TH400 in Almost Every Way

Rebuilding a Faster, Better TH400 in Almost Every Way

Gearstar Performance 5 minute read

Rebuilding a transmission, such as the TH400, is not relatively as easy as changing your car filter or making an oil change. It is a challenge that will take a...

A Detailed Look at Today's High-Performance Automatic Transmission

Gearstar Performance 6 minute read

If your AT experience in sports and muscle cars is limited to the three- and four-speed slushboxes of yore, let us say this: today’s high-performance...

C6 Transmission Upgrade Tips, Tricks, and Tech

C6 Transmission Upgrade Tips, Tricks, and Tech

Gearstar Performance 6 minute read

Have you ever wondered if it's possible to upgrade your C6 transmission to meet modern-day expectations in terms of toughness and performance? Yes, it is...

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