Syncro ring. Porsche 964 1989-94  ❭  92830421105

Synchro Ring – 3rd / 4th / 5th & Reverse Gear
Sold each - 4 required per car

Restore the smooth, precise gear changes your Porsche was designed to deliver with this OE Match Synchro Ring for the Porsche 964 manual gearbox. Manufactured to the original factory specification, this helps provide accurate synchronisation and helping restore crisp, positive gear engagement.

Fits:

• Porsche 964 (911) C2 1989-93
• Porsche 964 (911) C4 1989-93
• Porsche 964 (911) RS 3.6L 1991-93
• Porsche 964 (911) RS 3.8L 1991-93
• Porsche 964 (911) TURBO 3.3L 1991-93
• Porsche 964 (911) TURBO 3.6L 1991-93

Diagram Ref no 7

Each Porsche 964 manual gearbox uses four of these synchroniser rings, one for 3rd gear, 4th gear, 5th gear and reverse gear. Whether you're carrying out a complete transmission overhaul or replacing worn synchroniser components, this OE Match synchro ring offers factory-style fit, performance and durability.

What Does the Synchro Ring Do?

The synchro ring is a critical wear component within the manual transmission synchroniser assembly.

Its primary functions include:

• Synchronising the rotational speed of the selected gear and gearbox shaft before engagement.
• Allowing smooth, quiet gear changes without gear clash.
• Reducing wear on gear teeth, selector sleeves and synchroniser hubs.
• Improving shift quality and gear engagement.
• Protecting expensive internal gearbox components from premature wear.
• Maintaining the refined shifting performance expected from the Porsche 964 manual transmission.

A correctly functioning synchroniser ring is essential for smooth, accurate and reliable gear changes.

Why Do Synchro Rings Wear Out?

Synchroniser rings are designed to wear gradually during normal operation.

Common causes of wear include:

• High mileage.
• Frequent gear changes.
• Aggressive driving or rapid shifting.
• Worn or contaminated gearbox oil.
• Excessive gearbox temperatures.
• Wear to associated synchroniser hubs and selector sleeves.
• General fatigue of the friction surface over time.

As the friction material wears, the synchroniser becomes less effective at matching gear speeds, leading to more difficult gear selection and increased gearbox wear.

When Should the Synchro Ring Be Replaced?

Replacement is recommended when:

• Gear changes become stiff or notchy.
• Grinding or crunching occurs when selecting gears.
• The gearbox is stripped for overhaul.
• The synchroniser ring shows visible wear or damage.
• Replacing synchroniser hubs, selector sleeves or bearings.
• Rebuilding a high-mileage transmission.
• Preparing a gearbox for fast road or performance use.

Because gearbox disassembly is required, replacing all worn synchroniser rings during a rebuild is considered best practice.

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