do not press the back button…
Your Vehicle
Porsche // 964 (911) (1989-1994) // 964 (911) C4 1989-93
Enter your VAT number here and click Verify:
Your details have been verified. VAT number registered to:
,
.
Your order will now be zero rated for VAT purposes. We reserve the right to verify these details after your order request has been made and reinstate VAT if required.
Your VAT details were not recognised or were invalid. Your VAT number must be matched to your Billing Country as specified above. This is currently specified as . You do not need to enter the country code part of your VAT number as this has already been selected in your billing address details above.
The VAT number checking service is currently offline. Please supply your VAT details within the comments or special instructions field below and we will apply a VAT discount after placing your order request.
- Porsche 911 1965-1968 2.0L / 912 SWB (F)
- Porsche 911 1968-1973 2.2L / 2.4L / 2.7L RS LWB (F)
- Porsche 911 1974-1977 2.7L / 1976-77 3.0 Carrera
Fitting Position: Transmission End
Inner Diameter: 65 mm,
Outer diameter: 85 mm,
Width: 10 mm,
Fits:
Porsche 911 1965-77
Click 'Zoom in' for large part diagram.
Diagram Ref No 33
Related reference numbers
Related, superseded, cross reference or alternative numbers for comparison.
99911305752
The product you are viewing cross references to these numbers
- 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
- Porsche 993 (911) C2 1994-97
- Porsche 993 (911) C4 1994-97
- Porsche 993 (911) RS 1994-97
- Porsche 993 (911) C2S 1994-97
- Porsche 993 (911) C4S 1994-97
- Porsche 993 (911) TURBO 1994-96
- Porsche 993 (911) GT2 1994-97
- Porsche 993 (911) TURBO S 1994-97
- Porsche 996 TURBO 2000-05
- Porsche 996 GT2 2001-05
- Porsche 996 GT3 MKI 1999-02
- Porsche 924S 2.5L 1986-87
- Porsche 924S 2.5L 1988
- Porsche 944 2.5L 8V 1982-87
- Porsche 944 2.7L 8V 1988-89
- Porsche 944S 2.5L 16V 1987-88
- Porsche 944S2 3.0L 16V 1989-91
- Porsche 944 Turbo 2.5L 8V 1985-88
- Porsche 944 Turbo 2.5L 8V 1989-91
- Porsche 944 Turbo S 2.5L 8V 1988
- Porsche 968 3.0L 1992-94
- Porsche 968 Sport 3.0L 1994-95
- Porsche 968 CS 3.0L 1993-95
- Porsche 968 Turbo S 3.0L 1993-94
- Porsche 928 4.5L 1978-82
- Porsche 928S 4.7L 1981-83
- Porsche 928S2 4.7L 1984-86
- Porsche 928S4 5.0L 1987-92
- Porsche 928GT 5.0L 1989-91
- Porsche 928GTS 5.4L 1992-95
Restore engine sealing integrity and prevent costly oil leaks with this OE Match Rear Main Oil Seal for the Porsche 964, Porsche 993 and Porsche 996. Manufactured to OE specifications and measuring 90mm inner diameter, 110mm outer diameter and 12mm width, this critical engine seal is designed to prevent engine oil escaping around the rear of the crankshaft where it exits the engine case and connects to the flywheel assembly.
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
- Porsche 993 (911) C2 1994-97
- Porsche 993 (911) C4 1994-97
- Porsche 993 (911) RS 1994-97
- Porsche 993 (911) C2S 1994-97
- Porsche 993 (911) C4S 1994-97
- Porsche 993 (911) TURBO 1994-96
- Porsche 993 (911) GT2 1994-97
- Porsche 993 (911) TURBO S 1994-97
- Porsche 996 TURBO 2000-05
- Porsche 996 GT2 2001-05
- Porsche 996 GT3 MKI 1999-02
- Porsche 924S 2.5L 1986-87
- Porsche 924S 2.5L 1988
- Porsche 944 2.5L 8V 1982-87
- Porsche 944 2.7L 8V 1988-89
- Porsche 944S 2.5L 16V 1987-88
- Porsche 944S2 3.0L 16V 1989-91
- Porsche 944 Turbo 2.5L 8V 1985-88
- Porsche 944 Turbo 2.5L 8V 1989-91
- Porsche 944 Turbo S 2.5L 8V 1988
- Porsche 968 3.0L 1992-94
- Porsche 968 Sport 3.0L 1994-95
- Porsche 968 CS 3.0L 1993-95
- Porsche 968 Turbo S 3.0L 1993-94
- Porsche 928 4.5L 1978-82
- Porsche 928S 4.7L 1981-83
- Porsche 928S2 4.7L 1984-86
- Porsche 928S4 5.0L 1987-92
- Porsche 928GT 5.0L 1989-91
- Porsche 928GTS 5.4L 1992-95
Diagram Ref No. 21
The rear main oil seal, often referred to as the RMS (Rear Main Seal), is one of the most important sealing components in the engine. It retains engine oil inside the crankcase while allowing the crankshaft to rotate at high speed. A worn or damaged seal can lead to oil leaks, clutch contamination and unnecessary engine maintenance costs if left unattended.
This OE Match replacement provides the correct fit, sealing performance and durability required for maintenance, engine rebuilds and preventative servicing.
What Does the Rear Main Oil Seal Do?
The rear main oil seal forms a seal around the rear section of the crankshaft.
Its primary functions include:
- Preventing engine oil leaks
- Sealing the rear crankshaft opening
- Protecting the flywheel area from contamination
- Maintaining correct engine oil levels
- Preventing oil reaching the clutch assembly
- Supporting long-term engine reliability
- Allowing smooth crankshaft rotation
Without a properly functioning rear main seal, oil can escape from the engine and create a range of reliability issues.
Why Do Rear Main Oil Seals Fail?
Like all rubber sealing components, rear main oil seals are subject to wear and ageing.
Common causes of failure include:
- Heat cycling
- Age-related hardening
- Crankshaft wear
- Engine vibration
- Long-term oil exposure
- Improper installation
- Excessive crankcase pressure
- High mileage use
Over time, the sealing lip can lose flexibility and its ability to maintain consistent contact with the crankshaft surface.
Symptoms of a Failing Rear Main Oil Seal
Common warning signs include:
- Oil leaks between engine and gearbox
- Oil drips beneath the vehicle
- Oil contamination around the flywheel housing
- Clutch slip caused by oil contamination
- Burning oil smell
- Gradual oil level loss
- Oil residue on transmission bellhousing
Because the seal is located behind the flywheel, leaks can often be mistaken for other engine oil leaks unless properly diagnosed.
When Should the Rear Main Oil Seal Be Replaced?
Replacement is recommended when:
- Oil leakage is present
- The gearbox is being removed
- Replacing the clutch assembly
- Rebuilding the engine
- Refurbishing the crankshaft
- Carrying out preventative maintenance
- The original seal shows signs of ageing
- Engine mileage is high
Many Porsche specialists recommend replacing the rear main seal whenever the clutch or flywheel is removed, as labour access is significantly easier during these procedures.
Why Replacement Matters
A leaking rear main oil seal can lead to far more expensive repairs if ignored.
Benefits of replacement include:
- Prevention of engine oil leaks
- Protection of the clutch assembly
- Improved engine cleanliness
- Reduced maintenance costs
- Improved reliability
- Professional rebuild standards
- Long-term sealing performance
- Greater peace of mind
Replacing the seal during clutch or engine work is considered a smart preventative maintenance measure.
Related reference numbers
Related, superseded, cross reference or alternative numbers for comparison.
99911342642
The product you are viewing cross references to these numbers
- 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
Fits:Left and Right
Fits:
Porsche 964 1989-94
Porsche 993 1995-98
Diagram ref no 1
Related reference numbers
Related, superseded, cross reference or alternative numbers for comparison.
99970731340
The product you are viewing cross references to these numbers
- 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
- Porsche 993 (911) C2 1994-97
- Porsche 993 (911) C4 1994-97
- Porsche 993 (911) RS 1994-97
- Porsche 993 (911) C2S 1994-97
- Porsche 993 (911) C4S 1994-97
- Porsche 993 (911) TURBO 1994-96
- Porsche 993 (911) GT2 1994-97
- Porsche 993 (911) TURBO S 1994-97
Fits:
Porsche 964 1989-94
Porsche 993 1995-98
Click 'Zoom in' for large parts diagram
Diagram ref no 6
Related reference numbers
Related, superseded, cross reference or alternative numbers for comparison.
PCG113463A
The product you are viewing cross references to these numbers
- Porsche 911 1974-1977 2.7L / 1976-77 3.0 Carrera
- Porsche 911 1978-1983 3.0L / SC
- Porsche 911 1984-1986 3.2L
- Porsche 911 1987-1989 3.2L G50
- Porsche 911 1978-1989 3.3L Turbo (930)
- 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
- Porsche 993 (911) C2 1994-97
- Porsche 993 (911) C4 1994-97
- Porsche 993 (911) RS 1994-97
- Porsche 993 (911) C2S 1994-97
- Porsche 993 (911) C4S 1994-97
- Porsche 993 (911) TURBO 1994-96
- Porsche 993 (911) GT2 1994-97
- Porsche 993 (911) TURBO S 1994-97
- Porsche 996 TURBO 2000-05
- Porsche 996 GT2 2001-05
- Porsche 996 GT3 MKI 1999-02
- Porsche 997 MK1 TURBO 2007-09
- Porsche 997 MK1 GT3 / GT3 RS 2007-09
- Porsche 997 MK1 GT2 2007-09
- Porsche 997 MKII GT3 / GT3 RS 2010-11
- Porsche 997 MKII Turbo 2010-13
- Porsche 997 MKII GT2 RS 2011-13
Fits:
Porsche 911 1978-80
Porsche 911 1984-89
Porsche 964 1989-94
Porsche 993 1995-98
Porsche 996 Turbo 2001-05
Porsche 997 Turbo 2007-11
Porsche 996 GT3 2000-01
Porsche 997 GT3
Diagram ref no 27
Related reference numbers
Related, superseded, cross reference or alternative numbers for comparison.
99911329043
The product you are viewing cross references to these numbers