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          OEM 999-701-745-40 - Differential Cover O-Ring

          MPN: 999-701-745-40
          The OEM 999-701-745-40 Differential Cover O-Ring ensures a tight seal for your Porsche's differential, preventing leaks and maintaining optimal performance.
          0.0
          Vehicle Specific
          Check if this part fits your vehicle.
          • $8.80
          In stock

          Product Overview

          The OEM Differential Cover O-Ring, part number 999-701-745-40, is an essential component designed to maintain the integrity of your Porsche's differential system. This high-quality O-ring is engineered to OEM standards, ensuring a precise fit that prevents leaks and enhances the overall functionality of your vehicle. Crafted from premium-grade materials, this O-ring provides long-lasting durability and resistance against wear and tear. Its reliable sealing capabilities help to prevent oil leaks, safeguarding your differential and associated components from damage. The user-friendly design allows for quick and easy installation, making it a perfect choice for both professional mechanics and DIY enthusiasts. Choose OEM 999-701-745-40 for dependable performance and peace of mind every time you service your vehicle.

          Cross Reference Numbers

          This OEM 999-701-745-40 is equivalent to or replaces the following part numbers: 999 701 745 40, 99970174540.

          Vehicle Compatibility

          • Porsche 911 Carrera 3.6 H6 (1995–1998)
          • Porsche 911 Carrera 4 3.6 H6 (1995–1998)
          • Porsche 911 Carrera 4S 3.6 H6 (1997–1998)
          • Porsche 911 Targa 3.6 H6 (1996–1998)
          • Porsche 911 RS America 3.6 H6 (1993–1994)
          • Porsche 911 Speedster 3.2 H6 (1989)
          • Porsche 911 Carrera 2 3.6 H6 (1991–1998)
          • Porsche 911 Carrera 4 3.6 H6 (1989–1998)
          • Porsche 911 Carrera 3.2 H6 (1987–1988)
          • Porsche 911 Carrera 4 3.6 H6 (1990–1998)

          This may also fit other applications. Please use the vehicle selector tool to verify fitment.

          Why Shop at eEuroparts.com?

          • Proven Expertise: Over 25 years of experience with European vehicles means we know your car inside and out.
          • Exclusive Kits That Fitâ„¢ - complete repair solutions with no guesswork
          • Fitment Confidence: Our accurate cataloging ensures you get the right part the first time.
          • Fast, Reliable Shipping: Orders ship quickly from our U.S.-based warehouses.
          • Transparent Pricing: Competitive prices with no hidden fees or surprise charges.
          • Established Trust: Serving the European auto community since 2000.

          Frequently Asked Questions

          What does the OEM 999-701-745-40 Differential Cover O-Ring do?

          The OEM Differential Cover O-Ring is designed to create a tight seal between the differential cover and the differential housing. It prevents oil leaks, ensuring that the differential operates smoothly and efficiently, protecting critical components within the system.

          How do I know if my Differential Cover O-Ring needs replacement?

          Common signs of a failing O-ring include visible oil leaks around the differential cover, unusual noises from the differential area, and a decrease in differential fluid levels. If you notice any of these symptoms, it's advisable to check the O-ring for wear or damage.

          Can I install the OEM 999-701-745-40 myself?

          Yes, the installation of the OEM Differential Cover O-Ring is straightforward and suitable for DIY enthusiasts. However, always ensure the differential is properly drained and follow standard safety precautions during the installation process.

          What are the symptoms of a faulty Differential Cover O-Ring?

          Symptoms of a faulty O-ring include oil leaking from the differential area, decreased performance, and potential damage to the differential components. Regular checks can prevent further issues related to oil loss.

          Why should I choose OEM for my Differential Cover O-Ring needs?

          OEM parts are synonymous with quality and reliability. Order OEM 999-701-745-40 today for a factory-correct replacement that restores safety and performance.

          Note: All information on this page and in the FAQ is for general reference only. Verify fitment and consult a professional as needed. eEuroparts.com is not responsible for incorrect part selection or installation.

            • eEuroparts SKU
              1557251
            • Weight
              0.01 lbs
            • Dimensions (L x W x H)
              0.1 x 8 x 8 in
            • Manufacturer Part #
              999-701-745-40
          • Brand
            OEM
          • Manufacturer
            OEM
          • MPN
            999-701-745-40
          • Part Type
            Differential Cover O-Ring
          • OE Part Numbers
            999 701 745 40, 99970174540
          • Cross Reference Numbers
            99970174540
          • Fitment
            • Fitment Type
              Vehicle Specific
          YearMakeModelSubmodelNotes
          1987Porsche911Carrera (3.2 H6 GAS)
          1988Porsche911Carrera (3.2 H6 GAS)
          1989Porsche911Carrera (3.2 H6 GAS)
          1989Porsche911Carrera 4 (3.6 H6 GAS)Position: Front, Position: Rear
          1989Porsche911Speedster (3.2 H6 GAS)
          1990Porsche911Carrera 4 (3.6 H6 GAS)Position: Front, Position: Rear
          1990Porsche911Carrera 2 (3.6 H6 GAS)
          1991Porsche911Carrera 4 (3.6 H6 GAS)Position: Front, Position: Rear
          1991Porsche911Carrera 2 (3.6 H6 GAS)
          1992Porsche911Carrera 4 (3.6 H6 GAS)Position: Front, Position: Rear
          1992Porsche911Carrera 2 (3.6 H6 GAS)
          1993Porsche911Carrera 4 (3.6 H6 GAS)Position: Front, Position: Rear
          1993Porsche911Carrera 2 (3.6 H6 GAS)
          1993Porsche911RS America (3.6 H6 GAS)
          1994Porsche911Carrera 4 (3.6 H6 GAS)Position: Front, Position: Rear
          1994Porsche911Speedster (3.6 H6 GAS)
          1994Porsche911Carrera 2 (3.6 H6 GAS)
          1994Porsche911RS America (3.6 H6 GAS)
          1995Porsche911Carrera (3.6 H6 GAS)
          1995Porsche911Carrera 4 (3.6 H6 GAS)Position: Rear
          1996Porsche911Carrera (3.6 H6 GAS)
          1996Porsche911Carrera 4 (3.6 H6 GAS)Position: Rear
          1996Porsche911Targa (3.6 H6 GAS)
          1997Porsche911Carrera (3.6 H6 GAS)
          1997Porsche911Carrera 4 (3.6 H6 GAS)Position: Rear
          1997Porsche911Targa (3.6 H6 GAS)
          1997Porsche911Carrera 4S (3.6 H6 GAS)Position: Rear
          1998Porsche911Carrera (3.6 H6 GAS)
          1998Porsche911Carrera 4 (3.6 H6 GAS)Position: Rear
          1998Porsche911Targa (3.6 H6 GAS)
          1998Porsche911Carrera 4S (3.6 H6 GAS)Position: Rear
          1998Porsche911Carrera S (3.6 H6 GAS)
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          Warranty Overview

          At eEuroparts, we stand behind the quality of the products we sell. Every part we offer is backed by a warranty designed to give you peace of mind and protect your investment.

          Standard Warranty – Most Parts

          • Coverage: 2 years or 24,000 miles (whichever comes first) from purchase date.

          • Protection: Defects in materials or workmanship under normal personal use.

          • Eligibility: Applies only to the original purchaser and the vehicle where the part was first installed.

          • Exclusions:

            • Wear-and-tear items (brake pads, filters, bulbs, wipers, etc.)

            • Commercial, fleet, rideshare, off-road, or racing use

            • Improper installation, misuse, accidents, or modifications

          • Not Covered: Labor, shipping, towing, or incidental costs.

          Bison Performance Warranty – Our House Brand

          • Coverage: Limited Lifetime Warranty for as long as you own your vehicle.

          • Applies To: All products sold under the Bison Performance label.

          • Premium Protection: Goes beyond our standard warranty — if it’s a Bison product, the 2-year/24k mile limit is replaced with lifetime coverage.

          • Exclusions: Same as the standard warranty (normal wear, commercial use, improper installation, etc.).

          • What’s Included: Replacement of the defective product (labor and shipping excluded).

          Warranty Claim Requirements

          To keep claims fast and fair, we require:

          • Proof of purchase (invoice or order confirmation).

          • Photos or videos showing the defective part, order number, date, VIN, and odometer reading.

          • Diagnostic reports or part returns for non-visible issues may be requested.

          • Claims must be truthful, properly documented, and reflect normal consumer use.

          Buy With Confidence: We back our products because we believe in their quality, with a transparent, customer-first warranty process you can trust. And with Bison Performance products, you’ll enjoy Limited Lifetime protection—an assurance few brands can match.

          For full details and exclusions, please see our complete Warranty Terms & Conditions.

          This summary is for convenience only. For full warranty coverage details, exclusions, and requirements, see our official Warranty Terms & Conditions. In case of conflict, the full policy governs.

          Return Policy Overview

          Most parts can be returned within 30 days of delivery if unused, uninstalled, and in original packaging.
          To start a return, contact customer support via Chat or Contact Us.

          • Restocking fee: Up to 20% may apply for certain orders (buyer’s remorse, order errors, or special-order items)

          • Refunds: Issued to your original payment method within 3–5 business days after inspection

          • Exchanges: Not automatic — please return and reorder

          • Replacements: May be approved for incorrect or defective items reported within 7 days

          Not returnable:

          • Used or installed parts

          • Electrical components

          • Opened filter kits, gaskets, or contaminated items

          • Final sale or custom orders

          Important Notes:

          • Return shipping is your responsibility unless we made a verified error

          • Fitment is the customer’s responsibility (we can assist, but do not guarantee)

          • Country of origin may vary and is not grounds for return

          For complete details, please see our full Return Policy.


          This Returns summary is provided for convenience only. All returns, refunds, and exchanges are subject to the complete Returns Policy. In the event of any conflict, the full policy governs.

          Fast, Reliable Shipping — Straight to Your Door

          We ship most orders the same day when placed before 2 PM CST (Monday–Friday). Our main warehouse is just east of Nashville, TN, and we also ship from multiple locations nationwide to get your order to you as quickly as possible.

          • We use trusted carriers like UPS, FedEx, and USPS.

          • Tracking info is emailed to you as soon as your order ships.

          • Delivery estimates at checkout are based on carrier data, but not guaranteed.

          Need help with a shipment?

          If your order is missing, damaged, or incorrect, just let us know within 5 days of delivery. We’ll walk you through the quick claim process — including a few photos to help us make things right.

          For complete details, please see our full Shipping Policy.


          This Shipping summary is provided for convenience only. Delivery times, carrier terms, fees, restrictions, risk of loss, and other details are governed by our complete Shipping Policy. In the event of any conflict, the full policy governs.

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