JZX100 Diff Bush Replacement: Improving Performance & Reliability

JZX100 Diff Bush Replacement: A Worthwhile Upgrade

Swapping out the diff bushes on a JZX100 may seem like a daunting task, but with patience, the right tools, and a bit of elbow grease, it’s an achievable DIY project. In a recent session at Joe’s garage, the process of replacing worn-out diff and subframe bushes turned into a test of persistence—but the results were well worth the effort.

The Process

The car, a long and wide JZX100, was carefully positioned onto a small lift inside a limited garage space. The main objective? Removing and replacing the aging diff bushes with brand-new ones from Serial 9, a company known for high-quality performance parts. The job required dropping the entire rear subframe and differential—a task easier said than done.

Getting the old bushes out was no simple feat. Using a combination of brute force, chisels, and lubricants like WD-40, the team finally managed to knock them out. As expected, the old bushes showed clear signs of wear, oxidation, and age-related deterioration. The new Serial 9 bushes were pressed into place, ensuring a much firmer and more stable setup.

The Results

Once the replacement was complete, the JZX100 was taken for a test drive. The most noticeable improvement was the elimination of the knocking sound during gear shifts, particularly between 1st and 2nd gear, where the old worn-out bushes had previously caused excessive movement in the differential. The car also felt much more planted and responsive, making for a smoother and more controlled ride.

However, one lingering issue remained—at higher speeds, particularly in third gear at highway speeds, the car still exhibited a loose rear-end feel, almost as if steering from the back seats. Online forums suggest this could be due to worn trailing arm bushes, meaning another round of investigation and potential repairs is on the horizon.

Replacing the JZX100 diff bushes was an essential upgrade, bringing noticeable improvements in drivability and stability. While the process was tougher than expected, it was a worthwhile investment for anyone looking to refine their JZX100’s handling. If you’re tackling this job yourself, be prepared for a workout, and consider getting quality replacement parts from Serial 9 to make the effort worthwhile.

Stay tuned for further updates as we dive deeper into refining this JZX100’s performance!