Crankcase Parts

Rear Main Oil Seal. 90 x 110 x 12
Fitting Position: Transmission End,
Inner Diameter: 90 mm, Outer diameter: 110 mm, Width: 12 mm
Radial Shaft Seal Design

Fits:
Porsche 964 1989 - 1994
Porsche 993 1994 - 1998
Porsche 996 Turbo / GT2 / GT3 MKI
Porsche 944 - All models including 944S, 944 Turbo & 944S2 built 1982 - 1991
Porsche 924S - All models built 1986 - 1988
Porsche 928 - All models built 1986 - 1995
Porsche 968 - All models built 1992 - 1995

Diagram Ref No. 21

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Related, superseded, cross reference or alternative numbers for comparison.

99911342642

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Round seal 33,3 X 2,4 by Porsche for selected 911, 964, 993 and 996 applications. This O-ring is identified by part number 99970731540 and is used within crankcase and connection-piece assemblies.

Fits:

Porsche 911 1987–89 (Crankcase right)
Porsche 911 1984–86 (Crankcase right)
Porsche 964 1989–94 (Crankcase right)
Porsche 993 1994–98 (Crankcase right)
Porsche 996 GT3-1 M96.76 2000–01 (Crankcase right)
Porsche 996 GT3-1/GT3 RS M96.79 2004–05 (Crankcase right)

• Diagram reference number 30

Check fitment for your specific vehicle, model, year and engine before ordering.

What This Product Does

This O-ring forms a sealing interface within the relevant engine assembly, helping to contain fluids between mating components.

Functions

• Seals the specified crankcase or connection-piece interface
• Helps retain fluid within the assembly
• Supports correct fit between mating components
  
  

Technical Details

• Type: round seal / O-ring
• Size: 33,3 X 2,4

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Related, superseded, cross reference or alternative numbers for comparison.

99970731540

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Screw Socket. 

The Genuine Porsche Screw Socket (Part Number: 96410770523) is an original equipment threaded fitting associated with the engine crankcase and lubrication-system components of the Porsche 911 (964) generation.

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 52

Also referred to as a crankcase screwed socket or engine oil-system threaded connection, this component is intended to provide the specified mechanical connection within its applicable engine assembly.

The closely related Porsche reference 96410770522 is illustrated in the original Porsche 964 crankcase parts catalogue for the M64.50 engine, fitted to the Porsche 911 Turbo 3.6.

The exact reference 96410770523 is independently listed as a Porsche screwed socket, although its direct interchangeability with the earlier version requires confirmation.

The Porsche 964 Turbo 3.6 uses an air-cooled, turbocharged flat-six engine equipped with a dry-sump lubrication system.

This system relies on correctly assembled oil passages, fittings, seals and connecting components to maintain reliable oil circulation throughout the engine.

Threaded sockets used within the crankcase assembly provide specified connection points for the surrounding engine components.

Correct dimensions, thread engagement and installation are essential because an unsuitable fitting may not seat correctly or may damage the surrounding engine housing.

During normal operation, the engine assembly is exposed to vibration, mechanical loading, temperature changes and engine oil.

Over time, a threaded socket may become damaged through corrosion, overtightening, cross-threading or incorrect removal during engine servicing.

Damaged threads or sealing surfaces can compromise the security of the connection and may contribute to oil leakage if the fitting forms part of a sealed oil circuit.

Replacing a damaged screwed socket with the correctly specified Genuine Porsche component helps restore the original assembly arrangement, maintain secure fastening and support reliable engine operation.

Ideal for Porsche engine repairs, crankcase refurbishment and classic 911 Turbo restoration, this Genuine Porsche Screw Socket provides an original equipment replacement where its exact specification is required.

What This Product Does:
The screw socket is a threaded connection component associated with the relevant engine assembly.

Its primary purpose is to provide the specified interface for the corresponding mating component.

Depending on the engine configuration, crankcase screw sockets may serve as connection fittings within the lubrication system or provide a secure threaded mounting arrangement.

The exact function of 96410770523 must be confirmed against the applicable Porsche engine diagram.

Its general functions include:

• Providing a threaded connection: Creates the specified mechanical interface for the mating component.
• Supporting secure component attachment: Helps maintain the correct connection within the engine assembly.
• Maintaining original assembly geometry: Provides the intended dimensions and positioning.
• Supporting the crankcase arrangement: Forms part of the engine's original connection hardware.
• Maintaining correct thread engagement: Allows the corresponding component to be fitted securely.
• Supporting oil-system sealing where applicable: Helps maintain a sealed connection when used with the correct sealing arrangement.
• Withstanding engine operating conditions: Functions within an assembly exposed to heat and vibration.
• Supporting engine refurbishment: Allows damaged original fittings to be replaced during repairs.
• Preserving factory construction: Maintains the original Porsche component configuration.
• Providing serviceable connection hardware: Restores a damaged fitting without necessarily replacing the surrounding assembly.

Symptoms Of Wear Or Failure:
The screw socket is a passive mechanical component without moving parts.

Deterioration is generally associated with physical damage, incorrect installation, corrosion or repeated removal during servicing.

Common signs of a damaged screw socket include:

• Damaged threads: Stripped or worn threads may prevent secure engagement.
• Cross-threading: Incorrect installation may damage the fitting and surrounding component.
• Loose connection: A damaged socket may no longer retain its mating component correctly.
• Visible corrosion: Surface deterioration may affect the fitting's condition.
• Cracked socket body: Excessive tightening or mechanical stress may cause cracking.
• Distorted shape: Previous repairs or incorrect tools may deform the fitting.
• Damaged sealing surface: Scratches, pitting or deformation may compromise a sealed joint.
• Oil seepage: Where used in a sealed oil connection, damaged surfaces may contribute to leakage.
• Oil residue around the connection: A defective fitting or associated seal may allow oil to accumulate nearby.
• Difficulty removing the fitting: Corrosion or damaged tool-engagement surfaces may complicate servicing.
• Inability to tighten securely: Damaged threads may prevent the connection from reaching the specified fastening condition.
• Repeated loosening: A damaged mating connection may not retain the fitting reliably.
• Incorrect component fitment: An unsuitable socket may prevent proper assembly.
• Visible damage following engine repairs: Previous removal or installation may have compromised the component.
• Damage to the receiving threads: A defective fitting may be found alongside damage to the crankcase or mating component.

Why Replacement Matters:
Replacing a damaged screw socket helps maintain the correct mechanical connection within the engine assembly.

A fitting with stripped threads, cracks or distorted surfaces may no longer secure its mating component as intended.

Continued use of an unsuitable fitting may worsen damage to the surrounding threads or associated engine components.

Where the fitting is part of a sealed oil connection, deterioration can also compromise the integrity of that joint.

Installing a correctly specified Genuine Porsche replacement Screw Socket helps to:

• Restore secure thread engagement: Replace damaged or worn connection hardware.
• Maintain correct component fitment: Preserve the intended interface with the mating part.
• Replace damaged mounting hardware: Renew a cracked, corroded or distorted socket.
• Support oil-system sealing where applicable: Restore the correct connection arrangement when leakage originates from the fitting.
• Prevent further thread damage: Address unsuitable or damaged hardware before reassembly.
• Maintain engine assembly integrity: Reinstate the specified crankcase connection.
• Support engine refurbishment: Provide replacement hardware during engine repairs.
• Preserve original dimensions: Use the appropriate Porsche reference.
• Reduce future servicing difficulties: Replace seized or mechanically damaged fittings.
• Maintain factory specifications: Preserve the original engine hardware arrangement.
• Support classic Porsche restoration: Replace damaged components with Genuine Porsche parts.
• Support long-term reliability: Restore a sound connection within the engine assembly.

Replacement is recommended when the socket is cracked, corroded, cross-threaded, distorted or unable to provide secure attachment.

If the surrounding engine housing is damaged, further repair may be required before installing the replacement.

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

96410770523

The product you are viewing cross references to these numbers