Introduction

The driveshaft is a critical link between the transmission and the differential, transferring engine power to the rear wheels. On the Toyota Supra, the factory driveshaft is a robust component, but for enthusiasts chasing higher power levels, quicker throttle response, and reduced rotational mass, an aftermarket upgrade like the G-Force Performance Driveshaft offers clear advantages. This one-piece aluminum driveshaft replaces the original two-piece steel unit, eliminating the center support bearing and reducing weight by roughly 10–15 pounds. The result is improved drivetrain efficiency, less parasitic loss, and a more direct feel under acceleration.

This comprehensive guide walks you through the entire installation process, from preparation and safety to torque specs and post-installation checks. Whether you are a seasoned DIY mechanic or a Supra owner tackling this upgrade for the first time, the steps below will help ensure a successful, long-lasting installation. We have included expanded details on tools, common pitfalls, and maintenance tips to help you get the most out of your new G-Force driveshaft.

Benefits of the G-Force Performance Driveshaft

Before diving into installation, it is worth understanding what this upgrade provides beyond weight savings. The G-Force unit is precision-balanced and constructed from 6061-T6 aluminum with heavy-duty 1350-series U-joints. Key performance benefits include:

  • Reduced rotational mass: Lighter drivetrain components allow the engine to rev more freely and improve acceleration in every gear.
  • Elimination of the center support bearing: The two-piece factory shaft has a carrier bearing that can fail or introduce driveline vibrations at high horsepower. A one-piece shaft removes these failure points.
  • Improved strength: G-Force driveshafts are built to handle 800+ hp, making them a reliable choice for turbocharged Supras running upgraded fuel systems and turbos.
  • Direct bolt-in fitment: Designed specifically for the Toyota Supra (1993–2002, JZA80 chassis), the G-Force driveshaft requires no modifications to the transmission yoke or differential flange.

For more technical details and application notes, visit the G-Force Performance official website.

Tools and Materials Needed

Having the right tools on hand before you lift the car saves time and frustration. In addition to the driveshaft itself, you will need:

  • G-Force Performance Driveshaft (p/n GF1321 for Toyota Supra)
  • Floor jack and two jack stands (rated for at least 3 tons)
  • Metric socket set (10mm, 12mm, 14mm, 17mm, and 19mm sockets)
  • ½-inch drive torque wrench (ranging from 30–150 ft-lb)
  • Breaker bar for stubborn bolts
  • Safety glasses and mechanic’s gloves
  • Lithium-based grease or U-joint-specific grease
  • Thread-locking compound (medium strength, blue Loctite 242)
  • Rubber mallet (for gently aligning flanges)
  • Wire brush (to clean flange faces and bolt threads)
  • Penetrating oil (e.g., PB Blaster) for rusted fasteners

Optional but recommended: a helper to assist with lifting the driveshaft into position and a transmission jack for easier alignment. Also consider new OEM bolts for the differential and transmission flanges if the originals are corroded or over-torqued.

Safety Precautions

Working under a vehicle carries inherent risks. Observe the following safety measures throughout the installation:

  • Always park on a flat, solid surface. Concrete garage floors are ideal; avoid gravel or asphalt.
  • Chock the front wheels to prevent any rolling. Even with the parking brake engaged, it is wise to use wheel chocks.
  • Use jack stands rated for the vehicle’s weight. Never rely solely on a hydraulic jack — it can fail over time.
  • Wear safety glasses to protect against falling debris, grease splatter, or metal shavings.
  • Allow the exhaust and driveshaft components to cool if the car has been driven recently. Burns are a real risk.

Installation Steps

Step 1: Raise and Secure the Vehicle

Position the jack at the rear differential housing (not the axle tubes) and lift the rear of the Supra until the tires are about 8–10 inches off the ground. Place jack stands under the designated lift points on the chassis — typically the subframe or pinch welds near the rear control arms. Lower the car gently onto the stands and verify stability by pushing on the bumper. The vehicle should not rock.

For easier access, you may also raise the entire car on all four stands, but the driveshaft replacement requires only rear elevation.

Step 2: Remove the Old Driveshaft

Begin by locating the factory two-piece driveshaft. It runs from the transmission tail housing to the differential flange, with a center bearing mount secured to the transmission crossmember. Use a 14mm socket to remove the bolts at the transmission-side yoke (or the carrier bearing bolts if you are keeping the two-piece design — but for this upgrade you will discard the entire unit).

Next, remove the four 12mm bolts at the differential flange. These bolts are usually tight; apply penetrating oil if needed and use a breaker bar. Once all bolts are out, support the driveshaft with one hand and slide it rearward to disengage the transmission yoke. Be careful not to damage the transmission output shaft seal. The shaft will come out in two sections.

Remove the center bearing bracket with a 17mm socket and set the entire old assembly aside.

Step 3: Inspect and Prepare the Flanges

Before installing the new G-Force shaft, inspect the transmission output flange and differential pinion flange. Look for nicks, burrs, or corrosion on the mating surfaces. Use a wire brush to clean both flanges thoroughly. Check the condition of the transmission seal — if it shows leaking or wear, now is the time to replace it. A leaking seal will allow transmission fluid to drip onto the new driveshaft and eventually cause U-joint failure.

Apply a small amount of grease to the splines on the transmission output shaft. This will ease insertion of the yoke and prevent initial fretting. Do not over-grease — excess can contaminate the seal.

Step 4: Install the G-Force Performance Driveshaft

The G-Force driveshaft is pre-balanced and ready to install. With the help of an assistant (the shaft is roughly 50 inches long and can be awkward), slide the slip yoke onto the transmission output shaft. Ensure it engages fully — you should feel it seat into the splines. Rotate the shaft slightly if it doesn’t slide in easily. Gently tap the yoke with a rubber mallet if necessary, but do not force it.

Align the rear flange of the driveshaft with the differential flange. The bolt holes should line up exactly. Insert the supplied bolts by hand. If they are too tight to start, the flanges are misaligned — adjust the position of the shaft or have your helper rotate the differential flange slightly. Never use power tools to tighten bolts that aren’t started by hand.

Once all four bolts are hand-tight, move to the transmission yoke. Install the retaining bolts (usually four) into the yoke. Again, hand-tighten to secure the driveshaft in place.

Step 5: Torque the Bolts to Specification

Torquing the bolts correctly is critical. Use a calibrated torque wrench and follow these values (always verify with the manufacturer’s included instructions, as specs may vary slightly by batch):

  • Differential flange bolts: 65–70 ft-lb. Use a star or crisscross pattern to ensure even clamping force.
  • Transmission yoke bolts: 50–55 ft-lb. Apply a drop of medium-strength thread locker to each bolt before torquing.

Re-torque after 50 miles of driving, as new hardware can settle. Over-tightening can distort flanges or strip threads; under-tightening can cause vibration and bolt loosening.

For reference, the factory service manual recommends similar values, but aftermarket driveshafts often differ slightly. Check Suprastore’s torque specs page for additional confirmation.

Step 6: Lubricate the U-Joints

G-Force driveshafts come with serviceable U-joints. Locate the grease fittings (zerk fittings) on each U-joint. Attach a grease gun with lithium-based grease and pump until fresh grease purges from all four bearing seals. Wipe away the excess. Lubrication at this stage ensures the U-joints are protected from day one and reduces the risk of premature wear or vibration.

Step 7: Lower the Vehicle and Perform Final Checks

Remove the jack stands carefully, then lower the car so that the suspension is at normal ride height. With the car on the ground, check all fasteners one more time. Look for any clearance issues — the one-piece shaft has no center bearing, so it is important to ensure it does not contact the exhaust, transmission tunnel, or undercarriage. Spin the driveshaft by hand (with the transmission in neutral) and listen for any rubbing sounds. If you hear contact, inspect the area and adjust as necessary.

Sometimes a heat shield or exhaust hanger can be repositioned slightly.

Post-Installation Checks and Test Drive

Start the engine and allow it to idle in neutral. Listen for any unusual noises from the driveline. Engage reverse and then first gear, slowly releasing the clutch to verify smooth engagement. Take the car on a short test drive on a quiet road. Pay attention to the following:

  • Vibrations: Any shaking or resonance at certain speeds indicates a balance or alignment issue. A slight vibration at 70–80 mph may point to the driveshaft being out of phase or the flanges misaligned.
  • Noises: Clunking or clicking when accelerating or decelerating can mean loose U-joints or insufficient lubrication.
  • Driveline lash: Some increase in lash is normal after changing driveshaft design, but excessive play may require checking the differential or transmission output shaft bearings.

If everything feels smooth, perform a second run with the windows down to listen for any subtle sounds. After 50 miles, re-torque the flange bolts and inspect the U-joint caps for any signs of leakage.

Common Mistakes to Avoid

Several errors can compromise the installation. Here are the most common pitfalls and how to avoid them:

  1. Not cleaning flanges: Grease or debris between the flange faces can cause the shaft to sit at an angle, resulting in vibration.
  2. Over-tightening bolts: Aluminum flanges are more delicate than steel. Too much torque can strip threads or crack the flange. Always use a torque wrench.
  3. Ignoring transmission seal condition: A worn seal will leak fluid onto the new driveshaft and cause U-joint failure. Replace it proactively.
  4. Failing to grease U-joints: Even if the shaft is “pre-greased,” factory grease can settle during storage. Always add fresh grease.
  5. Not checking clearance: The one-piece shaft may sit closer to the exhaust or floorpan than the two-piece unit. Check for contact before driving.
  6. Skipping the re-torque: Bolts can loosen as components seat. Rechecking after a few miles is essential for long-term reliability.

Maintenance Tips

The G-Force driveshaft requires minimal routine care, but regular inspection helps extend its life:

  • Every oil change, check the U-joint grease fittings. If the joints feel dry or the boots are cracked, re-grease immediately.
  • Inspect bolts for looseness. A torque check every 10,000 miles is good practice.
  • After any hard track event or drag strip pass, inspect the flanges for signs of rotation or fretting.
  • If you lower the Supra significantly, verify that the driveshaft angle does not exceed 3–4 degrees; steep angles can accelerate U-joint wear. Adjustable toe arms or a lowering kit that maintains geometry can help.

Conclusion

Installing a G-Force Performance Driveshaft is one of the most rewarding drivetrain upgrades for a Toyota Supra. The reduction in rotational mass and the elimination of the center bearing transform the way the car delivers power — acceleration feels sharper, throttle response improves, and the driveline becomes more robust for high-horsepower applications. By following this expanded step-by-step guide, taking your time with preparation, and adhering to proper torque values and lubrication schedules, you can enjoy a reliable, vibration-free installation that will perform for thousands of miles.

For additional community insights and installation photos, the SupraForums driveshaft installation thread offers real-world tips from owners. Remember, attention to detail is the key to a successful aftermarket installation. Happy driving.