Gearbox Syncro Ring / Brake Band / Dog Teeth

Circlip for transmission gear. 
Sold each.



Fits:
Porsche 911 1965-71 (1. - 5th gear)
Porsche 911 1972-86 (3. - 5th gear)
Porsche 914 1970-76 (1. - 5th gear)
Porsche 924 1976-85 (4. - 5th gear)

Click 'Zoom in' for large parts diagram.
Diagram ref no 11

Circlip for transmission gear.
Sold each.



Fits:
Porsche 911 1965-71 (1. - 5th gear)
Porsche 911 1972-86 (3. - 5th gear)
Porsche 914 1970-76 (1. - 5th gear)
Porsche 924 1976-85 (4. - 5th gear)

Click 'Zoom in' for large parts diagram.
Diagram ref no 11

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91130231101

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Dog Teeth 1st Gear.
The OE Match 1st Gear Dog Teeth is a high-quality replacement gearbox component designed for Porsche manual transmissions. Manufactured to OE specifications for fit, precision and durability, this component forms a critical part of the gear engagement mechanism, allowing smooth and secure engagement of first gear during operation.  

Fits:

• Porsche 911 1974-1977 2.7L / 1976-77 3.0 Carrera
• Porsche 911 1978-1983 3.0L / SC
• Porsche 911 1984-1986 3.2L  

Diagram Ref No 43

The dog teeth ring is fitted to the gear assembly and works in conjunction with the synchroniser hub, synchroniser ring and selector sleeve. It provides the engagement points that lock the selected gear to the transmission shaft, ensuring efficient transfer of engine power through the gearbox. Precision machining is essential for smooth shifting performance and long transmission service life.  

What This Product Does:

• Provides the engagement surface for first gear selection.
• Works with the synchroniser assembly to enable smooth gear changes.
• Locks first gear to the transmission shaft when selected.
• Ensures efficient transfer of engine power through the gearbox.
• Supports accurate and reliable gear engagement.
• Helps minimise transmission wear during shifting.
• Contributes to smooth manual gearbox operation.

Symptoms Of Wear Or Failure:

• Difficulty engaging first gear.
• Gear crunching or grinding during gear selection.
• First gear jumping out of engagement under load.
• Increased resistance when shifting into first gear.
• Poor shift quality or inconsistent engagement.
• Excessive transmission noise during gear changes.
• Visible wear, rounding or chipping of the dog teeth during inspection.
• Premature wear of related synchroniser components.

Why Replacement Matters:

• Dog teeth are subjected to repeated engagement loads every time a gear is selected. Over time, the engagement surfaces can become worn, rounded or damaged, particularly in high-mileage transmissions or vehicles subjected to aggressive shifting. As wear progresses, gear engagement becomes increasingly difficult and less precise.
• A worn dog teeth ring can compromise synchroniser performance and may eventually prevent proper engagement of first gear. Continued operation with worn components can accelerate wear of synchroniser hubs, selector sleeves and other transmission parts, leading to more extensive and costly gearbox repairs.
• Replacing worn first gear dog teeth restores precise gear engagement, improves shift quality and helps protect the transmission from further internal wear. An OE Match replacement provides factory-style fitment, accurate machining and long-term durability, ensuring reliable gearbox operation and preserving the driving experience expected from your Porsche.

Related reference numbers
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91530224114

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Dog Teeth 1st Gear 911 1972-76 Symmetrical Tooth Point , 2 slots in hub (915 Trans. 1972-76)

Fits:
Porsche 911 2.4 / 2.7 1972 - 1976
for 915-gearbox symmetric

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91530224100

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Dog teeth 1st gear. Porsche 911 & 912 1965-71, 1st Gear with 4-Speed 2 slots in hub

Fits:
Porsche 911 1965-71

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90230224104

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Dog teeth 1st gear, G901 1st gear
Dog Teeth 911,912 1965-71, 914 All 1st Gear with 5-Speed transmission only, 2 slots in hub 
Sold individually

Fits:
Porsche 911 1965 - 1971
Porsche 914 All 1st Gear with 5-Speed

The dog teeth ring forms part of the gearbox synchroniser assembly. It works with the synchro ring, operating sleeve, and gear hub to allow the selected gear to engage smoothly. On 1st gear, the dog teeth are critical for clean gear selection, especially during low-speed driving, manoeuvring, and gearbox operation from rest.

Functions
•  Replaces the 1st gear dog teeth ring
•  Helps restore correct 1st gear engagement
•  Works with the synchro ring and operating sleeve
•  Supports smoother gear selection
•  Helps reduce crunching, baulking, or poor shift feel
•  Suitable for gearbox rebuilds and synchroniser repairs
•  OE Match replacement for classic Porsche transmission service.

Why Replace This Part?
Dog teeth can wear, chip, round off, or become damaged through age, high mileage, poor lubrication, worn synchro parts, or aggressive gear changes. Worn 1st gear dog teeth may cause difficult gear engagement, crunching, jumping out of gear, or poor shift quality. Replacing the dog teeth during gearbox overhaul helps restore reliable synchroniser operation and smoother 1st gear selection.

When to Replace This Part
•   1st gear is difficult to select
•   Crunching or baulking occurs when engaging 1st gear
•   The gearbox jumps out of 1st gear
•   The dog teeth are chipped, rounded, worn, or damaged
•   The synchro ring or operating sleeve is being replaced
•   The gearbox is being rebuilt or inspected
•   Preventative replacement is being carried out during transmission overhaul

Where it fits on the car
This dog teeth ring fits inside the gearbox on the 1st gear synchroniser assembly. It forms part of the internal gear engagement system and should be installed according to the factory gearbox layout.

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90130224106

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Dog teeth 1st gear. Porsche 911 Turbo 1975-76 (4 speed gearbox)  (Symmetrical Tooth Point)
   


Fits:
Porsche 911 Turbo 1975-76 4 speed

Click "Zoom in" to see the diagram.
Diagram Ref no 48.

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93030224103

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Dog Teeth 1st Gear (Asymmetrical Teeth) 

Restore crisp gear engagement and transmission performance with this OE Match 1st Gear Dog Teeth Ring, designed for Porsche 911 turbo (930) models produced between 1977 and 1988. Featuring the correct asymmetrical tooth profile used in the Porsche 930 gearbox, this critical synchroniser component plays a key role in ensuring smooth and reliable engagement of 1st gear.

Fits:

• Porsche 911 1978-1989 3.3L Turbo (930)

Diagram Ref no 48

Manufactured to OE specifications, this replacement dog teeth ring delivers precise machining, correct fitment and long-lasting durability for gearbox rebuilds, restorations and transmission repairs. Whether you're addressing difficult gear engagement, gearbox wear or carrying out a complete transmission overhaul, replacing worn dog teeth is essential for restoring proper shift quality.

What Do 1st Gear Dog Teeth Do?

The dog teeth ring is a fundamental part of the synchroniser assembly within the Porsche 930 gearbox. Mounted to the gear itself, the dog teeth provide the engagement surface that allows the synchroniser operating sleeve to lock the selected gear to the shaft during a gear change.

Working together with the synchroniser ring, guide hub and operating sleeve, the dog teeth help:

• Enable smooth gear engagement.
• Synchronise gear speeds before engagement.
• Reduce gear clash during shifting.
• Securely lock 1st gear into operation.
• Improve gearbox performance and shift quality.
• Support reliable transmission operation.

The asymmetrical tooth design used in many Porsche 930 gearbox applications was engineered to improve engagement characteristics and durability under the increased torque loads generated by the turbocharged engine.

Why Do Dog Teeth Fail?

Dog teeth are subjected to repeated mechanical impact every time a gear change is performed. Over time, wear gradually alters the tooth profile, reducing engagement quality and increasing synchroniser stress.

Common causes of failure include:

• High mileage gearbox wear.
• Aggressive shifting techniques.
• Repeated poor gear engagement.
• Worn synchroniser rings.
• Transmission oil contamination.
• Excessive gearbox loading.
• Age-related wear and fatigue.
• Incorrect gearbox setup during previous repairs.

First gear dog teeth are particularly susceptible to wear because they experience frequent engagement from stationary starts and low-speed driving.

When Should 1st Gear Dog Teeth Be Replaced?

Dog teeth should always be carefully inspected whenever the gearbox is dismantled. Replacement is recommended if you notice:

• Difficulty engaging 1st gear.
• Gear crunching during shifts.
• Jumping out of gear.
• Rounded or hooked tooth profiles.
• Excessive wear on synchroniser components.
• Poor shift quality.
• Visible damage or chipping.

During a professional Porsche 930 gearbox rebuild, worn dog teeth are commonly replaced alongside synchroniser rings, guide hubs and operating sleeves to restore factory shift performance.

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93030224102

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2nd Gear Dog Teeth

Restore precise gear engagement and transmission performance with this OE Match 2nd Gear Dog Teeth Ring designed for Porsche 911 turbo (930) models produced between 1977 and 1988. As a critical component of the synchroniser assembly, the dog teeth ring allows smooth and reliable engagement of 2nd gear, helping maintain the shifting quality and driving characteristics expected from the legendary Porsche Turbo drivetrain.

Fits:

• Porsche 911 1975-1977 3.0L Turbo (930)
• Porsche 911 1978-1988 3.3L Turbo (930)

Diagram Ref no 35

Manufactured to OE specifications, this replacement dog teeth ring delivers precise machining, excellent durability and factory-correct fitment. Whether you're rebuilding a Porsche 930 gearbox, addressing synchroniser wear or carrying out a full transmission restoration, replacing worn dog teeth is essential for achieving smooth gear changes and long-term gearbox reliability.

What Do 2nd Gear Dog Teeth Do?

The dog teeth ring is mounted directly to the gear and forms an essential part of the Porsche 930 synchroniser system. During a gear change, the synchroniser assembly matches the rotational speed of the selected gear before the operating sleeve engages the dog teeth to lock the gear to the shaft.

The dog teeth perform several vital functions:

• Enable smooth engagement of 2nd gear.
• Provide the engagement surface for the operating sleeve.
• Help synchronise gear speeds during shifting.
• Reduce gear clash and transmission wear.
• Maintain precise gear selection.
• Support reliable gearbox operation under load.

In the high-torque Porsche 930 transmission, properly functioning dog teeth are critical for maintaining shift quality and preventing excessive wear to other synchroniser components.

Why Do 2nd Gear Dog Teeth Fail?

Dog teeth are subjected to repeated impact loads during every gear change. Over time, wear gradually alters the shape of the engagement teeth, reducing their effectiveness and causing shifting issues.

Common causes of failure include:

• High mileage transmission wear.
• Aggressive shifting and rapid gear changes.
• Worn synchroniser rings.
• Poor gearbox lubrication.
• Contaminated transmission oil.
• Excessive drivetrain loading.
• Gear grinding during engagement.
• Age-related wear and fatigue.

Second gear is one of the most frequently used gears during normal driving, making its synchroniser and dog teeth assembly particularly vulnerable to long-term wear.

When Should 2nd Gear Dog Teeth Be Replaced?

The dog teeth ring should always be inspected whenever the gearbox is dismantled. Replacement is recommended if you notice:

• Difficulty engaging 2nd gear.
• Crunching or grinding during shifts.
• Rounded or hooked engagement teeth.
• Gear engagement becoming increasingly notchy.
• Visible wear, chipping or damage.
• Excessive synchroniser wear.
• Transmission rebuild requirements.

Most Porsche gearbox specialists recommend replacing worn dog teeth during transmission overhauls to restore smooth shifting and protect other synchroniser components from premature wear.

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93030224200

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Dog Teeth 3rd/4th/5th Gear. (3 per gearbox)
G901 2rd to 5th Gear,
G915 3rd to 5th Gear

Manual transmission gear teeth are precision-engineered ridges on the gears inside a manual gearbox. These teeth interlock to transfer power from the engine to the driveshaft. Their exact shape and alignment ensure smooth gear engagement, efficient torque delivery, and dependable performance across all gear ratios. Keeping the gear teeth strong and undamaged is crucial for preventing slippage, maintaining power, and extending the overall life of the transmission.

Fits:
Porsche 911 1974-1977 2.7L / 1976-77 3.0 Carrera (915 Gearbox)
Porsche 911 1978-1983 3.0L / SC (915 Gearbox)
Porsche 911 1984-1986 3.2L (915 Gearbox)

Signs of Manual Transmission Gear Teeth Failure

• Grinding or whining noises during shifting, often caused by worn or damaged teeth.
• Difficulty engaging gears due to misaligned or broken gear teeth.
• Loss of power or gear slippage when the teeth can no longer mesh correctly.

Diagram Ref no 6, 15, 23.

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90130224203

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3rd / 4th Gear Dog Teeth 

Restore precise shifting performance and gearbox reliability with this OE Match 3rd / 4th Gear Dog Teeth Ring designed for Porsche 911 Turbo (930) models produced between 1975 and 1988. As a vital component within the synchroniser assembly, the dog teeth ring allows smooth engagement of 3rd and 4th gears, helping maintain the crisp shifting characteristics expected from the legendary Porsche Turbo transmission.

Fits:

• Porsche 911 1975-1977 3.0L Turbo (930)
• Porsche 911 1978-1988 3.3L Turbo (930)

Diagram Ref no 32 & 34

Manufactured to OE specifications, this replacement dog teeth ring provides accurate machining, correct tooth geometry and exceptional durability for transmission rebuilds, restorations and performance maintenance. Whether you're rebuilding a worn gearbox or restoring a classic Porsche 930 to factory standards, replacing worn dog teeth is essential for preserving smooth gear selection and transmission longevity.

What Do 3rd / 4th Gear Dog Teeth Do?

The dog teeth ring forms an integral part of the Porsche 930 synchroniser assembly. Mounted to the gear, it provides the engagement interface between the gear and the synchroniser operating sleeve.

During a gear change, the synchroniser system matches rotational speeds between components before the operating sleeve engages the dog teeth, locking the selected gear to the shaft and transmitting engine power through the transmission.

The dog teeth help:

• Enable smooth engagement of 3rd and 4th gears.
• Provide positive gear locking during operation.
• Reduce gear clash during shifting.
• Improve gear change precision.
• Support synchroniser operation.
• Maintain reliable gearbox performance under load.

Properly functioning dog teeth are essential for preserving the smooth shift quality and driving enjoyment of the Porsche 930 transmission.

Why Do 3rd / 4th Gear Dog Teeth Fail?

Over time, repeated gear changes gradually wear the engagement surfaces of the dog teeth. As wear increases, gear engagement quality deteriorates and additional stress is placed on the synchroniser assembly.

Common causes of failure include:

• High mileage wear.
• Aggressive driving and fast shifting.
• Worn synchroniser rings.
• Gear grinding during engagement.
• Contaminated gearbox oil.
• Inadequate transmission maintenance.
• Excessive drivetrain loads from turbocharged performance.
• Age-related metal fatigue.

Third and fourth gears often see frequent use during normal road driving and higher-speed operation, making their synchroniser components susceptible to long-term wear.

When Should 3rd / 4th Gear Dog Teeth Be Replaced?

Dog teeth should be inspected whenever the gearbox is dismantled or rebuilt. Replacement is recommended if you experience:

• Difficulty engaging 3rd or 4th gear.
• Gear crunching or grinding during shifts.
• Rounded, hooked or worn engagement teeth.
• Excessive synchroniser wear.
• Poor shift quality.
• Visible damage or chipping.
• Transmission rebuild requirements.

Most Porsche transmission specialists replace worn dog teeth alongside synchroniser rings, guide hubs and operating sleeves during gearbox overhauls to ensure optimal shifting performance.

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93030224300

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Gearshift sleeve, 1st - 2nd Gear.



Fits:
Porsche 911 1972-77 915 Manual Transmission
not for 915/60/61 gearboxes

Click 'Zoom in' for large parts diagram.
Diagram ref no 42

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91530241100

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Synchro Brake Band 1st Gear.
Manual transmission Synchro / Brake Band (Synchroniser band) engineered to match Porsche’s original specifications. Provides friction control during gear synchronisation, allowing smooth and quiet gear changes.

Fits:
Porsche 911 1974 - 1986 (915 Gearbox)

Diagram ref no 37

The synchro / brake band is part of the gearbox synchroniser system, helping to slow or control rotation of a gear or hub during shift transitions, promoting smooth engagement and preventing clash. It works in concert with the synchroniser rings, hubs, sleeves, and gearsets to align speeds of rotating parts before lock-in. Proper material, friction surface, and design are critical — the band must provide the correct friction characteristics without binding or excessive wear.

•  Installation: Direct OE replacement — recommended during gearbox overhaul
•  Position / Location:  This part is located inside the manual transmission, within the synchroniser assembly — the mechanism that equalizes gear and shaft speeds for smooth engagement. It wraps around the synchroniser hub and works with the synchro ring and dog teeth gear to provide friction and control during shifting.
•  Benefits: Restores synchroniser performance, eliminates grinding, reduces wear on gears and rings

Why replacement matters:
•  With use, the original band’s friction surfaces can glaze, wear, or lose consistency, impairing its ability to slow or stabilise gear/hub motion during shifting.
•  A worn or ineffective brake / synchro band can result in grinding gears, missed shifts, or gear clash, especially under load or during aggressive shifting.
•  Installing a high-quality replacement restores proper friction behaviour, enabling smooth engagement, reducing wear on adjacent synchroniser elements, and extending transmission life.
•  Because the transmission internals are sensitive to mismatches or degraded components, having a reliable replacement band ensures system integrity and maintains the “feel” of the gearbox.

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92830231908

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Synchro Brake Band 1st Gear.
The 92830231908 is a genuine Porsche synchroniser brake band (often referred to as a synchro band or braking ring) used inside Porsche manual gearboxes.

Fits:
Porsche 911 1974 - 1986 (915 Gearbox)

Diagram ref no 37

•  This synchro brake band is located inside the manual transmission (gearbox) — not externally visible.
•  It forms part of the synchroniser mechanism, mounted between the hub sleeve and gear cone.
•  Its job is to provide controlled friction to help the synchro ring synchronise gear speed during shifting.

The synchro / brake band operates under constant friction every time the driver shifts gears. Over years of driving, this friction causes wear on the band’s friction surface and tension. When it wears out:
•  Gear changes become stiffer or notchy
•  Drivers may experience grinding noises when shifting into 1st or 2nd gear
•  The transmission may “crunch” or resist engaging lower gears
•  There may be slippage or hesitation before the gear fully engages.
If ignored, a worn synchro band can damage associated parts — like the synchro rings, hubs, or even gear teeth.

Replacement is recommended during:
•  Transmission rebuilds or overhauls (especially if the gearbox is open)
•  When experiencing hard or noisy shifting into 1st or 2nd gear
•  After high mileage or track use, where shifting load is higher
•  Anytime a synchro ring or gear hub is replaced — the band should be renewed at the same time.
Because it’s an internal gearbox part, it’s most efficiently replaced during gearbox servicing or clutch/transmission removal work.

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92830231908

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Synchro Brake Band 2nd Gear.
The OE Match 2nd Gear Synchro Brake Band is a high-quality replacement transmission component designed to ensure smooth and precise engagement of second gear in Porsche manual gearboxes. Manufactured to OE specifications for fit, accuracy and durability, this brake band forms an integral part of the synchroniser assembly, helping to equalise gear speeds before engagement occurs.

Fits:

• Porsche 911 1974-1977 2.7L / 1976-77 3.0 Carrera
• Porsche 911 1978-1983 3.0L / SC
• Porsche 911 1984-1986 3.2L  

Diagram Ref No 39

Working alongside the synchroniser ring, dog teeth, synchroniser hub and selector sleeve, the synchro brake band creates the friction required to slow or accelerate rotating gearbox components, allowing second gear to engage smoothly and efficiently. Precision engineering ensures reliable gear synchronisation, improved shift quality and reduced wear on internal transmission components.  

What This Product Does:

• Assists in synchronising gear speeds before second gear engagement.
• Works as part of the transmission synchroniser assembly.
• Helps provide smooth and accurate gear changes.
• Reduces gear clash and grinding during shifting.
• Supports proper operation of the synchroniser ring and hub.
• Minimises wear on transmission engagement components.
• Contributes to reliable manual gearbox performance.

Symptoms Of Wear Or Failure:

• Difficulty engaging second gear.
• Gear grinding or crunching when shifting into second.
• Increased resistance during gear changes.
• Notchy or inconsistent shift quality.
• Requirement to shift slowly to avoid gear clash.
• Excessive gearbox noise during gear engagement.
• Poor synchronisation between gear and shaft speeds.
• Accelerated wear of synchro rings, dog teeth and selector sleeves.

Why Replacement Matters:

• The synchro brake band is subjected to constant friction and wear every time second gear is selected. Over time, the friction surfaces can wear down, reducing the component's ability to equalise rotational speeds before gear engagement. This can result in difficult shifting, gear clash and increased stress on other synchroniser components.
• A worn brake band can compromise synchroniser performance and accelerate wear throughout the gearbox. If left unresolved, continued operation may lead to damage of synchro rings, dog teeth and selector sleeves, potentially resulting in more extensive and costly transmission repairs.
• Replacing a worn synchro brake band restores proper synchronisation, improves shift quality and helps protect the gearbox from premature internal wear. An OE Match replacement provides factory-style fitment, precision manufacturing and long-term durability, ensuring smooth and dependable transmission operation for your Porsche.

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92830231801

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