Built to Hold
Build guides, transmission tech, and install notes from the Gearstar shop floor. Every unit we ship is assembled by one builder, matched to your combo, and dyno-tested before it goes out the door. This is where we show the work: what holds, what grenades, and how to spec it right the first time.
4L80E Upgrades: Top Performance Parts to Boost Your Transmission
Discover essential 4L80E upgrades, including the Gearstar Billet Direct Drum with oversized sprag, 300M input and main shafts, and supporting components....
How the Right 700R4 Torque Converter Transforms Performance
If you’ve ever finished a round of engine upgrades: camshaft, intake, headers, maybe even EFI, and then felt underwhelmed the first time you left a...
Essential 6L90 Transmission Upgrades
If there’s one thing GM got right with the 6L90 transmission, it’s that they built it to survive real work. Found behind heavy-duty trucks, performance...
4R70W Transmission Controller Explained
This guide explains the 4R70W transmission controller, the electronic brain that commands shifts and lockup. Learn why factory computer control fails for...
4L80E Direct Drum in Performance Rebuilds
In the hierarchy of critical components inside a 4L80E, the direct drum rarely gets the attention it deserves. Builders often focus on shafts,...
What Is a Billet Direct Drum? Strength, Design, and Why It Matters
If there were a popularity contest in the world of transmission components, the direct drum might not even get an invite. Most people don’t know it...