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    Eaton Posi Service Kit | Preload Spring & Plate Kit | 29590-00S

    Vendor: Eaton
    Part Number: 29590-00S
    Regular Price $107.99

    Available to order. In-stock orders typically ship in 1 to 2 business days.

    Not sure it fits your vehicle?
    Email sales@berryperformancesales.com with your year, make, model and engine, and we'll help you check fitment before you order.
    Fast Fulfillment: In-stock orders typically ship within 1 to 2 business days.
    Free Shipping on Orders Over $99 | Excludes freight shipments
    International Shipping Available: email sales@berryperformancesales.com for a quote.
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    This Eaton Posi service kit supplies preload spring and plate hardware used to rebuild and re-tension a clutch-type Eaton Posi limited-slip differential. Swapping the preload springs lets the clutch bias be reset or tuned during a rebuild.

    • Type: Eaton Posi preload service kit (springs and plates)
    • Fits: clutch-type Eaton Posi limited-slip differentials
    • Use: rebuild and clutch-preload tuning
    • Gear ratio: fits all ratios
    • Sold as: service kit
    • Part number: 29590-00S

    Axle Fitment

    • Service kit for Eaton Posi clutch-type limited-slip units. Verify the Posi model and internal spring/plate configuration before ordering.

    FAQ

    What does the Eaton 29590-00S service kit include?

    It supplies the preload springs and plates used to rebuild and re-tension a clutch-type Eaton Posi limited-slip differential.

    What is this kit used for?

    It is used during an Eaton Posi rebuild to restore or retune the clutch preload that sets the differential's bias.

    Does this kit fit all gear ratios?

    Yes. The preload hardware is not ratio-specific and works with all ratios, but confirm it matches your Posi model.

    Is this a complete differential?

    No. Part 29590-00S is a service kit for an existing Eaton Posi unit, not a complete differential.

    Shipping Policy
    • Free shipping on orders over $99 (excludes freight shipments).
    • In-stock orders typically ship within 1 to 2 business days. Weekend and holiday orders are processed the next business day.
    • Orders ship from Defiance, Ohio and a nationwide network of warehouses and manufacturers.
    • Items showing an ETA are not in stock yet. ETAs come from the manufacturer and can change.
    • No P.O. Boxes. International orders need a shipping quote, so email us first.

    Read the full Shipping Policy

    Return Policy
    • 30-day return window from the ship date. Returns must be approved first; email sales@berryperformancesales.com with your order number.
    • Items must be unused, complete and in the original packaging.
    • A 20% restocking fee applies, and return shipping is paid by the buyer.
    • Not returnable: installed or modified parts, opened or used programmers and tuners, custom orders, Open Box, and Clearance or Final Sale items.
    • Damaged, defective or incorrect items must be reported within 48 hours of delivery with photos.

    Read the full Return Policy

    Disclaimer

    All products are sold for off-road use only unless otherwise specified. Buyer assumes all responsibility for installation and operation. Seller is not liable for any incidental, indirect, or consequential damages — including engine failure, labor costs, or vehicle downtime — resulting from the use of any product sold.

    By making a purchase from Berry Performance Sales, you acknowledge and agree to abide by the terms and conditions of these Policies.

    For any questions or concerns, please contact us — we’re always happy to help.

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