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.
Crankshaft & Parts
Fits:
Porsche 356 /A/B/C (1950 to 1965)
Porsche 912 (1965 to 1969)
Click 'Zoom in' for large parts diagram.
Diagram ref no 47
Related reference numbers
Related, superseded, cross reference or alternative numbers for comparison.
99911301250
The product you are viewing cross references to these numbers
- Porsche 356 1950-55
- Porsche 356A 1955-59
- Porsche 356B 1959-63
- Porsche 356C 1963-65
- Porsche 912E 4CYL 1976
Crankshaft Oil Seal
Protect your classic Porsche engine from oil leaks with this Crankshaft Oil Seal. This
high-quality oil seal is manufactured to OE specifications, providing a
reliable seal around the crankshaft where it exits the engine casing.
Constructed from durable, oil-resistant materials, it is designed to withstand
high temperatures, engine oil and constant crankshaft rotation while delivering
long-lasting performance.
Fits:
- Porsche 356 1950-55
- Porsche 356A 1955-59
- Porsche 356B 1959-63
- Porsche 356C 1963-65
-
Porsche 912E 4CYL 1976
Diagram ref no 47
Whether you're rebuilding an engine, replacing a leaking seal or carrying out preventative maintenance, this OE Match crankshaft oil seal offers dependable sealing performance and factory-style fitment.
What Does the Crankshaft Oil Seal Do?
The crankshaft oil seal prevents engine oil from escaping where the crankshaft passes through the engine case while keeping dirt, dust and moisture away from internal engine components.
Its key functions include:
- Preventing engine oil leaks
- Maintaining correct engine oil pressure
- Protecting the crankshaft opening from contamination
- Supporting long-term engine reliability
A correctly functioning seal is essential for keeping the engine clean, lubricated and operating efficiently.
Why Do Crankshaft Oil Seals Fail?
Over time, the sealing lip is subjected to continual contact with the rotating crankshaft, as well as heat and exposure to engine oil.
Common causes of failure include:
- Age-related hardening of the seal
- Heat cycling
- Wear of the sealing lip
- Oil contamination
- Incorrect installation
- Crankshaft surface wear
As the seal deteriorates, engine oil can begin to seep or leak from the crankshaft opening.
When Should It Be Replaced?
Replacement is recommended if:
- Oil is visible around the crankshaft area
- The seal shows signs of hardening or cracking
- The engine is being rebuilt
- The flywheel or pulley has been removed
- Preventative maintenance is being carried out on an older engine
Replacing the seal during engine work is inexpensive preventative maintenance that can help avoid future oil leaks and unnecessary labour costs.
Porsche 356 & 912 Engine Seals
Engine oil seals play a vital role in maintaining the reliability of classic Porsche engines. As rubber seals age, they gradually lose their flexibility and sealing ability, allowing oil leaks to develop that can affect engine cleanliness and reliability.
Replacing crankshaft oil seals during routine servicing or engine rebuilds helps maintain correct lubrication, reduce oil loss and protect valuable engine components. OE Match seals are manufactured to provide factory-style fitment and dependable long-term performance, making them an ideal choice for restoration and maintenance projects.
Benefits of Replacing the Crankshaft Oil Seal
- Prevents engine oil leaks
- Maintains proper engine sealing
- Protects against dirt and moisture ingress
- Ideal during engine rebuilds
- Long-lasting, oil-resistant materials
Related reference numbers
Related, superseded, cross reference or alternative numbers for comparison.
99911301250
The product you are viewing cross references to these numbers
- Porsche 356 1950-55
- Porsche 356A 1955-59
- Porsche 356B 1959-63
- Porsche 356C 1963-65
- Porsche 912E 4CYL 1976

3G Mineral Grease: To coat journal prior to use of Plastigauge
3G Silicone Grease: To apply to surface of shell
Lubricants to assist with the measurement of clearance in automotive bearings.
Plastigauge Precision Clearance Gauges

Fits: Crankshaft Pulley End
Fits:
Porsche 911 1974-89
Porsche 930 Turbo
Speedi Sleeves to Repair Worn, Grooved Seal Surfaces
Over time, sealing surfaces will become grooved, making a good seal impossible.The most economical and fastest method of shaft repair is to install the CR Speedi Sleeve. Speedi Sleeve is a precision engineered piece of stainless steel. It's ultra-thin wall design allows it to be used without changing the sel size ans its finish is perfect for lip sealing applications. Speedi Sleeve is built with removable installation flange. The installation tool included in every box allows the seal to be put in. This avoids the possibility of distortion from heat or other installation methods.
Related reference numbers
Related, superseded, cross reference or alternative numbers for comparison.
91110299189
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 356 1950-55
- Porsche 356A 1955-59
- Porsche 356B 1959-63
- Porsche 356C 1963-65
Fits:
Porsche 356 - 1950 to 1965 (intermediate shaft)
Porsche 928 - 1978 to 1995 (oil pimp drive pulley)
Porsche 944 2.5ltr - 1982 to 1984 (crankshaft pulley)
Porsche 955 Cayenne S / turbo - 2003 to 2006 (crankshaft pulley and oil pump drive pulley)
Porsche 957 Cayenne S / GTS / turbo - 2007 to 20010 (crankshaft pulley)
Porsche 957 Cayenne S / GTS / turbo - 2007 to 20010 (crankshaft pulley)
Porsche 970 Panamera 4.8ltr V8 - 2009 to 2016 (crankshaft pulley)
Diagram ref no 3
Related reference numbers
Related, superseded, cross reference or alternative numbers for comparison.
N0127131
The product you are viewing cross references to these numbers
- Porsche 955 Cayenne S 4.5L V8 2003-06
- Porsche 955 Cayenne Turbo 4.5L 2003-06
- Porsche 955 Cayenne Turbo S 4.5L 2006>>
- Porsche 957 Cayenne S / GTS 4.8L 2007-10
- Porsche 957 Cayenne Turbo / Turbo S 4.8L 2007-10
- Porsche 958 Cayenne S V8 4.8L Petrol (400Hp) 2010-17
- Porsche 958 Cayenne GTS V8 4.8L Petrol (400Hp) 2010-17
- Porsche 958 Cayenne Turbo V8 4.8L Petrol (500Hp) 2010-17
- Porsche 958 Cayenne Turbo S V8 4.8L Petrol (550Hp) 2010-17
- Porsche 970.1 Panamera S V8 4.8L 2009-13
- Porsche 970.1 Panamera 4S V8 4.8L 2009-13
- Porsche 970.1 Panamera GTS V8 4.8L 2011-13
- Porsche 970.1 Panamera Turbo V8 4.8L 2009-13
- Porsche 970.1 Panamera Turbo S V8 4.8L 2009-13
- Porsche 970.2 Panamera GTS V8 4.8L 4WD (440Hp) 2014-16
- Porsche 970.2 Panamera Turbo V8 4.8L (520Hp) 2014-16
- Porsche 970.2 Panamera Turbo V8 Executive 2014-16
- Porsche 970.2 Panamera Turbo S V8 4.8L 2014-16
- Porsche 944 2.5L 8V 1982-87
- 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
- Porsche 356 1950-55
- Porsche 356A 1955-59
- Porsche 356B 1959-63
- Porsche 356C 1963-65

Fits:
Porsche 356 1950-1965 All Types
Porsche 912 1965-69
Click 'Zoom in' for large parts diagram.
Diagram ref no 13
Related reference numbers
Related, superseded, cross reference or alternative numbers for comparison.
N0127091
The product you are viewing cross references to these numbers
- Porsche 911 1965-1968 2.0L / 912 SWB (F)
- Porsche 356 1950-55
- Porsche 356A 1955-59
- Porsche 356B 1959-63
- Porsche 356C 1963-65
Precision Crankshafts & Components – Engine Balance, Power, and Reliability for Porsche Models
The crankshaft is the backbone of every Porsche engine, responsible for transforming the reciprocating motion of pistons into smooth, rotational power. It endures immense pressure, heat, and mechanical load — making precision, strength, and perfect balance essential for sustained performance.
At Design911, we stock a comprehensive range of high-precision crankshafts and related components, including main bearings, thrust washers, oil seals, dowels, bolts, and pulleys. Each component is engineered from motorsport-grade materials to deliver optimal strength, fatigue resistance, and rotational balance for both classic and modern Porsche engines.
Whether you’re carrying out a complete engine rebuild or restoring a vintage air-cooled flat-six, our manufacturer-quality crankshaft parts ensure durability, smooth operation, and maximum efficiency under all driving conditions.
What Do Crankshafts and Crankshaft Parts Do?
The crankshaft plays a central role in the internal combustion process, converting piston motion into rotational energy that powers the drivetrain. Supporting components like bearings, seals, and bolts keep it perfectly aligned and lubricated for friction-free motion.
Core Functions:
- Convert linear piston motion into rotational energy to drive the vehicle.
- Maintain engine balance and smoothness across the RPM range.
- Support precise oil flow and bearing lubrication for reduced friction.
- Ensure stable load distribution, protecting connecting rods and bearings.
High-precision crankshaft assemblies are fundamental to maintaining Porsche’s signature smoothness, responsiveness, and reliability.
Why Do Crankshafts Fail?
Even the strongest crankshaft components can wear or fail over time due to extreme forces, lubrication issues, or age-related fatigue. Left unaddressed, these issues can lead to major engine damage.
Common Causes of Failure Include:
- Oil starvation, leading to bearing wear and journal scoring.
- Excessive vibration from imbalance or worn dampers.
- Cracks or fatigue stress caused by high RPM or detonation.
- Bearing seizure due to contamination or low oil pressure.
- Improper torque or alignment during rebuilds.
Replacing worn or damaged components during an engine rebuild restores smooth rotation, lubrication integrity, and power delivery.
Why Replace with Precision-Engineered Crankshaft Components?
Using high-quality, precision-balanced crankshaft parts is vital to maintaining your Porsche’s performance and reliability. Upgrading or replacing aged components improves both powertrain smoothness and long-term engine life.
Key Benefits:
- Restores rotational balance and smooth power delivery.
- Prevents bearing failure and vibration from worn journals or misalignment.
- Improves oil control and lubrication efficiency.
- Enhances reliability and engine lifespan under load or high-RPM conditions.
- Crafted from forged or billet materials for strength and durability.
- Precision-fit design for both air-cooled and water-cooled Porsche engines.
Engine rebuilders and performance specialists trust these components to achieve race-grade precision with road-going reliability.
Highlights:
- Comprehensive range of crankshafts, bearings, bolts, and seals for Porsche engines.
- Precision-balanced components for smooth and efficient rotation.
- Motorsport-grade materials ensure exceptional fatigue resistance.
- Ideal for classic rebuilds, performance upgrades, and preventive maintenance.
- Perfect fitment across air-cooled and modern Porsche models.
- Restores original power delivery, efficiency, and reliability.