High-Performance Transmission & Drivetrain Upgrades in Castro Valley

Building a high-horsepower engine is only half the battle. If your vehicle is still running a factory transmission, open differential, and stock axles, all that extra engine power is just going to result in spinning tires, slipping clutches, or catastrophic mechanical failure.

At Boulevard Auto Repair & Performance, we specialize in high-performance transmission and drivetrain upgrades for track cars, street builds, and heavy-duty vehicles across Castro Valley, San Leandro, and Hayward. We engineer your driveline to handle aggressive launches, tight cornering, and massive torque.
 

Stop wasting power. [Schedule your performance drivetrain consultation online] with our expert builders today.
 

Performance Clutch & Lightweight Flywheel Installations

A factory clutch is designed for smooth, gentle, daily commuting. When you add serious power, the factory pressure plate can no longer clamp down hard enough, causing the clutch to slip and burn up under heavy acceleration.

• Performance Clutches: We install Stage 1, 2, and 3 clutch kits tailored to your exact horsepower goals and driving style. Whether you need a heavy-duty organic disc for aggressive street driving or a multi-puck ceramic clutch for the drag strip, we source the best components from brands like ACT, Exedy, and McLeod.

• Lightweight Flywheels: While replacing your clutch, upgrading to a forged chromoly or aluminum lightweight flywheel is one of the best modifications you can make. By removing heavy rotational mass from the engine, your vehicle will rev noticeably faster, delivering much sharper throttle response and quicker acceleration.
   

Limited Slip Differential (LSD) Upgrades

Most factory cars come equipped with an "open" differential. When you take a hard corner or launch the car, an open diff sends all your engine power to the wheel with the least amount of traction—resulting in the dreaded "one-wheel peel."

Upgrading to a Limited Slip Differential (LSD) completely transforms how your car handles. A mechanical LSD (like a helical gear or clutch-pack style diff) locks the axle under acceleration, forcing power equally to both wheels. This means you get explosive straight-line launches, aggressive traction out of tight corners, and massive improvements in track lap times.

Note: High-performance LSDs require highly specific friction modifiers and heavy-duty gear oil. We utilize premium European-spec fluids from Motul and Liqui Moly for all of our [differential and transfer case] services.
 

Heavy-Duty Axles & Driveshafts

Traction is great, but if your tires finally hook up and your axles are weak, the sudden jolt of torque will literally snap a factory CV axle in half.

For high-horsepower builds, we replace your thin factory axles with heavy-duty, high-strength chromoly CV axles and upgraded driveshafts. These reinforced components are engineered to withstand the extreme torsional stress of hard launches on sticky racing tires, ensuring your driveline stays in one piece when the light turns green.
 

The Perfect Match for Engine Swaps

A custom drivetrain is the ultimate finishing touch for a major powertrain conversion. If we are performing a high-revving [Honda engine swap] (like a K20/K24) or a massive torque-heavy [Chevy LS build], we will custom-tailor your transmission gearing, clutch setup, and axle strength to perfectly match the power output of your new engine. We don't just build fast cars; we build reliable ones.

Don't let a weak drivetrain hold back your build. [Schedule your performance drivetrain consultation online] at Boulevard Auto in Castro Valley today.