Terra Firma Automotive supplies genuine Nissan transmission synchro rings that restore smooth and precise gear changes to your Z32 manual gearbox. This early-style 4th gear baulk synchro ring is the exact OEM friction cone responsible for synchronizing shaft speeds when shifting into fourth gear. Produced to Nissan’s original design with the correct taper angle and high-performance friction surface, it ensures quick, quiet engagement and reduces the mechanical stress on the gear teeth and synchronizer hub.
Fourth gear is a high-speed gear that sees frequent use during highway driving and spirited acceleration. When the original ring wears, shifts into 4th often become notchy, grindy, or hesitant. This authentic early-version replacement brings back the factory-smooth transition, eliminates unwanted noise, and helps protect the rest of the transmission internals from accelerated wear.
At Terra Firma Automotive we stock these specific synchro components because they are among the most commonly needed parts during a proper Z32 transmission rebuild or refresh. Whether you are overhauling the gearbox on your twin-turbo, correcting shifting problems on a naturally aspirated example, or performing a complete synchro service on your 1989–1996 Fairlady Z or 1990–1996 300ZX, this 4th gear baulk ring is a key piece for regaining that satisfying, factory-correct shift quality.
- Genuine Nissan OEM early 4th gear baulk synchro ring (Part Number 32604-40P21)
- Direct fit for all Z32 manual transmissions
- Factory-specified friction material and cone geometry
- Eliminates grinding and hesitation when selecting 4th gear
- Essential during synchro refresh or full transmission rebuilds
- Helps extend the life of 4th gear, hub, and shift fork
- Sold individually (best replaced as a set with related synchro rings)
- USDM 300ZX (Z32): 1990–1996 (VG30DE & VG30DETT – NA or TT)
- JDM Fairlady Z (Z32): 1989–1996 (VG30DE & VG30DETT – NA or TT)
- Engine Compatibility: Fits all VG30DE and VG30DETT engines with manual transmission
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