The Nissan 370Z has earned its reputation as a driver’s car thanks to its powerful VQ37VHR engine, sharp handling, and accessible price point. Yet even the most enthusiastic owners eventually find themselves chasing more immediate acceleration and a more visceral connection to the pavement. One upgrade that delivers exactly that without touching the engine or forced induction is a final drive gear swap. Mfactory’s final drive upgrade for the Nissan 370Z promises to sharpen throttle response and improve acceleration while keeping your budget intact at just $900. In this article we’ll explore exactly what this upgrade involves, how it transforms the driving experience, and whether it belongs on your short list of performance modifications.

What Is a Final Drive Upgrade?

A final drive upgrade replaces the ring and pinion gears inside your vehicle’s differential. These gears determine the final multiplication of torque from the transmission before it reaches the wheels. The ratio—often expressed as a number like 3.69:1 or 4.08:1—defines how many times the driveshaft rotates to turn the axles once. A numerically higher ratio (shorter gearing) means the engine spins faster for a given road speed, which multiplies torque and produces stronger acceleration. A numerically lower ratio (taller gearing) reduces engine RPM at cruise, favoring fuel economy and top speed.

On the Nissan 370Z, the stock final drive ratio is typically 3.69:1 for manual transmission cars and 3.36:1 for automatic models. Mfactory’s upgrade offers a shorter ratio—commonly 4.08:1 or similar—designed to wake up the car’s mid-range and deliver a more urgent launch. This change affects every gear in the transmission, meaning you’ll feel the benefit from a stoplight all the way through the quarter-mile.

Why Upgrade the Final Drive on a Nissan 370Z?

The 370Z already offers strong straight-line performance stock, but the factory gearing prioritizes a balance of fuel economy, emissions, and quiet cruising. Many owners report that the car feels slightly lethargic off the line, especially when compared to modern turbocharged rivals. By shortening the final drive, you effectively give each gear more mechanical advantage. The result is a car that feels lighter on its feet, pulls harder in every gear, and rewards aggressive throttle inputs with instant forward motion.

This upgrade also plays well with other common modifications. If you’ve added an intake, exhaust, or a tune, the engine is capable of producing more power, but that power still has to be multiplied by the gearing. A final drive swap ensures that extra output translates into real acceleration gains. For naturally aspirated builds, it’s one of the most effective ways to improve seat-of-the-pants performance without forced induction.

Key Benefits of the Mfactory Final Drive Upgrade

  • Improved Acceleration: The shorter gearing reduces the time it takes to reach any given speed. Independent tests and owner reports show 0-60 mph times dropping by 0.3–0.5 seconds, with even larger gains in the 60–100 mph range. The car feels noticeably quicker in daily driving and on track.
  • Better Power Delivery: Because the engine spends more time in its powerband, you’re always closer to peak torque. This translates to stronger pull exiting corners and less need to downshift for highway passing. The power feels more immediate and linear.
  • Enhanced Driving Engagement: Higher engine RPM at highway speeds adds a more aggressive exhaust note and a constant reminder that you’re driving a performance machine. Many owners describe the car as “alive” after the swap, with a more connected feel through the throttle.
  • Cost-Effective Performance: At $900 for the gear set, this upgrade rivals or beats the cost-per-horsepower of typical bolt-on parts. Unlike an intake or exhaust that may only add 5–10 hp, a final drive change produces a tactile difference you can feel in every gear.
  • High-Quality Manufacturing: Mfactory uses 8620 steel alloy, shot-peened surfaces, and precision CNC machining to ensure strength and durability. Their gears are designed to handle increased power levels from supercharged or turbocharged builds, making them a future-proof choice.

Installation: What to Expect

Tools and Skill Level Required

Installing a final drive gear set is not a beginner-friendly job. It requires mechanical experience, specialized tools (dial indicator, bearing puller/installer, torque wrench, and a press), and a clean workspace. Most owners choose to have the work done by a qualified performance shop. Labor costs typically range from $400 to $800, depending on your region and the shop’s rates. Factor this into your total budget when planning the upgrade.

Step-by-Step Installation Overview

  1. Remove the rear differential assembly from the vehicle. This involves disconnecting the driveshaft, axle shafts, and differential mounting bolts. The differential is heavy—use a transmission jack or have an assistant.
  2. Drain the differential fluid and thoroughly clean the exterior to prevent debris from entering during disassembly.
  3. Disassemble the differential case. Remove the carrier, side bearings, and pinion gear. Mark shim positions and bearing caps for reassembly.
  4. Replace the ring and pinion gears with Mfactory’s set. This requires pressing the new pinion bearing onto the pinion gear, setting pinion depth with shims, and installing the ring gear on the carrier.
  5. Set the gear backlash and preload using a dial indicator and torque wrench. Proper setup is critical for quiet operation and long gear life. Mfactory provides target specifications—follow them exactly.
  6. Reassemble the differential with new bearings (recommended), new seals, and fresh gear oil. Use a high-quality synthetic 75W-90 limited-slip differential fluid.
  7. Reinstall the differential in the car, reconnect all driveline components, and torque bolts to factory specifications.
  8. Test drive carefully. Listen for whine or vibration. A slight gear whine under acceleration is normal with aftermarket gears, but excessive noise may indicate incorrect setup. Break in the new gears gently for the first 500 miles.

Pro Tips for a Smooth Install

  • Always replace the side bearings, pinion bearings, and seals while you have the differential apart. The cost is minimal compared to the labor of doing it again later.
  • Use a dial indicator with a magnetic base to measure backlash accurately. Aim for 0.005–0.008 inches as specified by Mfactory.
  • Apply marking compound to the ring gear teeth to check the contact pattern. Adjust shims as needed to achieve a centered pattern.
  • Consider upgrading to a limited-slip differential (LSD) with higher torque bias at the same time. The upgrade complements the shorter gears and improves corner exit traction.

Performance After the Upgrade

Once the Mfactory final drive is installed and properly broken in, the change is immediately apparent. The 370Z feels like it has shed several hundred pounds. Acceleration from a standstill is more urgent, and the car pulls harder through the mid-range. On a track or autocross course, the shorter gearing means you can stay in a lower gear longer, keeping the engine in its sweet spot through corners. Many owners report lap time improvements of 1–2 seconds on a typical road course due to better corner exit speed and reduced need for mid-corner shifts.

It’s worth noting that fuel economy will drop slightly—expect a decrease of 1–3 MPG depending on your driving style—and highway cruising RPM will increase by roughly 300–400 rpm. For most enthusiasts, the trade-off is well worth the increased fun factor. The car feels more alive at legal speeds, and the added gear whine (if present) becomes part of the character rather than a nuisance.

Is the Mfactory Upgrade Worth $900?

To answer that, consider what other $900 modifications offer. A cat-back exhaust system adds sound and maybe 5–10 hp, but the gains are often marginal at the wheels. A cold air intake offers similar small power increases. A performance tune can unlock 20–30 whp on the VQ37VHR, but that requires a $600–$800 ECU flash or piggyback system, and you still have the same stock gearing. The final drive upgrade changes how the car uses any power it already has—including power from those other mods. It multiplies the effectiveness of every other performance part you install later.

Furthermore, the Mfactory gear set is built to withstand significant power levels. If you eventually add forced induction, the gears will handle 500+ whp without failing. This makes the $900 investment a durable foundation for a long-term build. Compared to the cost of a supercharger kit ($5,000–$7,000) or a full transmission swap ($3,000+), the final drive upgrade delivers a high percentage of enjoyment per dollar spent.

Long-Term Reliability and Maintenance

Mfactory gears are heat-treated and shot-peened to resist fatigue. With proper installation and regular fluid changes, they should last the life of the vehicle. However, aftermarket gears can produce more noise than stock due to their steeper tooth angle. Some owners report a constant low-pitched whine, especially in 6th gear on the highway. This is normal and does not indicate wear. If the noise becomes excessive, check gear oil level and condition, and verify that the installation setup specs are still within range.

Recommended maintenance after the upgrade includes a differential fluid change every 30,000 miles or every two years, whichever comes first. Use a high-quality synthetic gear oil with limited-slip additives if your 370Z is equipped with a factory viscous LSD or if you have installed an aftermarket LSD. Avoid using cheap fluids, as poor lubrication can accelerate gear wear and lead to premature failure.

Alternatives to Consider

  • Other Gear Ratios: Mfactory offers multiple ratios beyond the common 4.08:1, including 4.36:1 and 3.917:1. The 4.36:1 is extreme and ideal for autocross or track-only cars, while 3.917:1 offers a middle ground for street-driven cars that still see highway miles.
  • Complete Differential Assembly: Instead of a gear set, you can purchase a complete pumpkin with the gears already installed. OS Giken and Cusco offer units with built-in LSDs, but these cost $2,000–$3,000. The Mfactory gear set is a more budget-friendly entry point.
  • Transmission Gearing Changes: Some owners opt for closer-ratio gears inside the transmission (available from PPG or Z1 Motorsports), but this is far more expensive and labor-intensive than a simple final drive swap.
  • Lightweight Flywheel: A lighter flywheel reduces rotational inertia and helps the engine rev faster, but it does not multiply torque like a gear ratio change. It’s a complementary mod, not a substitute.

Frequently Asked Questions

Will the Mfactory final drive upgrade affect my speedometer?

Yes. The speedometer reads speed from the transmission (or ABS sensors), not the differential. Changing the final drive ratio does not alter the speedometer calibration on the 370Z. However, your indicated speed will be the same as before; only the engine RPM at a given speed changes.

Can I install the gears myself without special tools?

While it is possible with basic hand tools and a press, achieving the correct setup requires a dial indicator, inch-pound torque wrench, and patience. Most DIY mechanics without differential experience will struggle to set backlash and pinion depth accurately. We recommend having the work done by a shop that specializes in gear installations.

How long does installation take?

An experienced shop can complete the swap in 4–6 hours. First-timers should plan for a full weekend. The diff removal and reinstallation are the most time-consuming parts; the actual gear swap takes about 1–2 hours once the diff is on the bench.

Will the upgrade void my Nissan warranty?

Any modification can potentially void warranty coverage if it causes damage or is deemed to have caused a failure. The final drive is a drivetrain component, so if the differential fails due to defective gears, Nissan may deny warranty claims. On a vehicle that is out of the factory warranty period (common for most 370Zs), this is not a concern.

Does the 370Z need an LSD for this upgrade to work?

No, the Mfactory gear set fits the stock open differential or the factory viscous LSD. However, because the shorter gears increase torque multiplication, an LSD becomes more valuable for putting that power down effectively, especially in corners. If your 370Z has an open diff, consider upgrading to an LSD at the same time.

Conclusion

Mfactory’s final drive upgrade transforms the Nissan 370Z from a capable sportscar into a genuinely quick and engaging machine. For $900 plus installation, you gain acceleration that rivals or exceeds bolt-on modifications costing twice as much. The gear set is built to handle serious power, so it remains relevant whether you keep your Z naturally aspirated or add forced induction down the road. If you’re looking for a single modification that changes the way your car feels and performs every time you drive it, the Mfactory final drive is a compelling choice. Check the Mfactory product page for current ratio options, and consult your local performance shop to discuss installation. Your 370Z will thank you.