3rd Gear Shift Sleeve. Porsche 924 › 92830241313

Synchro Shifting Sleeve 1st/2nd Gear. 
The OE Match Synchro Shifting Sleeve, 1st/2nd Gear is a high-quality replacement transmission component designed to facilitate the engagement of first and second gears within Porsche manual gearboxes. Manufactured to OE specifications for fit, precision and durability, this shifting sleeve forms a critical part of the synchroniser assembly, ensuring smooth, accurate and reliable gear selection.

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 42

Working in conjunction with the synchroniser hub, synchro rings and dog teeth, the shifting sleeve slides across the synchroniser assembly to engage the selected gear once rotational speeds have been synchronised. Precision machining and correct fitment are essential for maintaining shift quality, reducing gearbox wear and ensuring dependable transmission performance.  

What This Product Does:

• Engages first and second gears within the gearbox.
• Works with the synchroniser assembly to enable smooth gear changes
• Transfers movement from the gear selector mechanism to the selected gear.
• Helps ensure accurate and positive gear engagement.
• Supports proper synchronisation before gear selection.
• Reduces gear clash and transmission wear.
• Contributes to smooth manual gearbox operation and drivability.

Symptoms Of Wear Or Failure:

• Difficulty engaging first or second gear.
• Gear grinding or crunching during shifts.
• Notchy or inconsistent gear changes.
• Excessive resistance when moving the gear lever.
• Gear disengagement or jumping out of gear under load.
• Poor shift quality and reduced transmission precision.
• Increased gearbox noise during gear changes.
• Visible wear, chipping or rounding of engagement surfaces during inspection.

Why Replacement Matters:

• The synchro shifting sleeve experiences repeated mechanical loading every time first or second gear is selected. Over time, the engagement surfaces can wear, become rounded or suffer damage, reducing the sleeve's ability to engage gears cleanly and securely.
• A worn shifting sleeve can compromise gear engagement, place additional strain on synchroniser rings and dog teeth, and accelerate wear throughout the gearbox. If left unresolved, continued operation may lead to increasingly poor shift quality and more extensive transmission repairs.
• Replacing a worn synchro shifting sleeve restores accurate gear engagement, improves transmission performance and helps protect other synchroniser components from premature wear. An OE Match replacement provides factory-style fitment, precision manufacturing and long-term durability, ensuring smooth and reliable shifting performance for your Porsche manual transmission.

Related reference numbers
Related, superseded, cross reference or alternative numbers for comparison.

93030241103

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Synchro shifting sleeve 3rd/4th gear.

Fits:
Porsche 911 1974-86 (915 Gearbox)

Click "Zoom in" to see the diagram.
Diagram Ref no 13.

Related reference numbers
Related, superseded, cross reference or alternative numbers for comparison.

91130241128

The product you are viewing cross references to these numbers

Synchro Guide Sleeve 3rd/4th Gear – 915 Gearbox

Restore the precise shifting performance of your classic Porsche 911 with this OE Match 3rd/4th Gear Synchro Guide Sleeve, designed specifically for Porsche 911 models equipped with the renowned 915 gearbox between 1974 and 1986. As a critical component within the synchroniser assembly, the guide sleeve helps ensure smooth gear engagement and accurate gear selection between third and fourth gears.

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 12

Manufactured to OE specifications, this replacement synchro guide sleeve provides the correct fit, machining accuracy and durability required for Porsche transmission rebuilds and restorations. Whether you are addressing gear selection issues, carrying out a gearbox overhaul or restoring a classic air-cooled 911, replacing worn synchroniser components is essential for maintaining smooth and reliable gear changes.

What Does the 3rd/4th Gear Synchro Guide Sleeve Do?

The synchro guide sleeve is a vital component within the Porsche 915 gearbox synchroniser assembly. It works alongside the synchroniser rings, brake bands, anchor blocks and operating sleeves to allow gears to engage smoothly and without excessive wear.

When a gear change is made, the guide sleeve helps control the movement of the synchroniser mechanism, ensuring rotational speeds between gears are matched before engagement occurs.

The guide sleeve performs several important functions:

• Guides synchroniser operation during gear changes.
• Supports smooth engagement of 3rd and 4th gears.
• Helps synchronise gear speeds before engagement.
• Reduces gear clash and transmission wear.
• Maintains precise gear selection.
• Contributes to the distinctive shifting feel of the Porsche 915 gearbox.

Without a properly functioning guide sleeve, gear engagement quality can deteriorate significantly.

Why Do Synchro Guide Sleeves Fail?

The synchroniser system experiences constant mechanical loading during every gear change. Over time, wear and fatigue can affect the guide sleeve and associated synchroniser components.

Common causes of failure include:

• Wear from repeated shifting cycles.
• Metal fatigue over high mileage.
• Poor lubrication caused by contaminated gearbox oil.
• Aggressive or incorrect shifting techniques.
• Excessive wear in synchroniser assemblies.
• Gearbox overheating.
• General age-related component deterioration.

As many Porsche 911 models equipped with the 915 transmission are now several decades old, wear within the synchroniser system is extremely common and often contributes to poor shift quality.

When Should a Synchro Guide Sleeve Be Replaced?

The synchro guide sleeve should be carefully inspected whenever the gearbox is dismantled. Replacement is recommended if you experience:
Difficulty selecting 3rd or 4th gear.

• Gear crunching during shifts.
• Notchy or inconsistent gear engagement.
• Gearbox rebuild requirements.
• Excessive wear on synchroniser components.
• Visible scoring, damage or distortion.
• Transmission noise associated with worn synchroniser assemblies.

Most transmission specialists recommend replacing worn synchroniser components during a gearbox overhaul to restore optimal shift quality and prevent premature future wear.

Related reference numbers
Related, superseded, cross reference or alternative numbers for comparison.

91130240222

The product you are viewing cross references to these numbers

Synchro Guide Hub 91530240102 1st/2nd Gear – 915 Gearbox

Restore the crisp shifting performance of your classic Porsche 911 with this OE Match Synchro Guide Hub. Designed specifically for Porsche 911 models fitted with the legendary 915 gearbox between 1974 and 1986, this precision-engineered component forms a critical part of the 1st and 2nd gear synchroniser assembly, helping to ensure smooth gear engagement and reliable transmission 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 41

Manufactured to OE specifications, this replacement synchro guide hub delivers the correct fit, strength and dimensional accuracy required for professional gearbox rebuilds and classic Porsche restorations. Whether you're addressing worn synchroniser components, improving shift quality or carrying out a complete transmission overhaul, replacing worn guide hubs helps restore factory gear change performance.

What Does the 1st/2nd Gear Synchro Guide Hub Do?

The synchro guide hub is a central component within the Porsche 915 gearbox synchroniser assembly. Located between 1st and 2nd gears, it provides the mounting and guidance structure for the synchroniser mechanism and works in conjunction with the operating sleeve, synchro rings, brake bands and anchor blocks.

Its primary function is to facilitate smooth gear engagement by helping synchronise the rotational speeds of the gears before they lock together.

The guide hub helps:

• Support the synchroniser assembly.
• Control movement of the operating sleeve.
• Facilitate smooth 1st and 2nd gear engagement.
• Reduce gear clash during shifting.
• Maintain accurate gear selection.
• Improve overall gearbox operation and shift quality.

A properly functioning guide hub is essential for preserving the characteristic feel and reliability of the Porsche 915 transmission.

Why Do Synchro Guide Hubs Fail?

Over decades of service, synchroniser components are subjected to constant mechanical stress and repeated gear changes. Wear and fatigue can gradually affect the guide hub and surrounding synchroniser parts.

Common causes of failure include:

• High mileage wear.
• Aggressive shifting habits.
• Repeated gear engagement stress.
• Excessive synchroniser wear.
• Poor gearbox lubrication.
• Contaminated transmission oil.
• Metal fatigue over time.
• Damage during previous gearbox repairs.

Because 1st and 2nd gears are often the most frequently used ratios, the synchroniser assembly in this area of the gearbox is commonly one of the first sections to show wear.

When Should a Synchro Guide Hub Be Replaced?

The synchro guide hub should be inspected whenever the gearbox is dismantled or rebuilt. Replacement is recommended if you experience:
Difficulty engaging 1st or 2nd gear.

• Gear crunching during shifts.
• Notchy gear changes.
• Excessive transmission wear.
• Visible scoring, cracking or damage.
• Worn synchroniser assemblies.
• Poor shift quality despite replacing synchro rings.

Most Porsche transmission specialists recommend replacing worn synchroniser components during a gearbox overhaul to ensure consistent performance and maximise gearbox longevity.

Related reference numbers
Related, superseded, cross reference or alternative numbers for comparison.

91530240102

The product you are viewing cross references to these numbers