USA Standard Gear

Differential Locker

$54.89

SKU: ZP MINSF9-31

In Stock
In Stock
Ships by Aug 31
Free Shipping over $200
$100 Minimum Order
30 Days Return

Description

It replaces the spider gears within a standard open carrier, ensuring that power is delivered to both rear wheels 100% of the time. This full-time lockup is ideal for drag racing, sled pulling, or off-road use where consistent traction is critical. Constructed as a low-cost solution for enhanced grip, this mini spool is specifically engineered for Ford 9-inch rearends with 31-spline axles. Its installation into an existing open carrier simplifies the upgrade process for enthusiasts looking to maximize power delivery. While providing significant traction benefits, the USA Standard Gear mini spool is explicitly not recommended for street-driven vehicles due to its full-time locking nature, which can affect steering and tire wear under normal driving conditions. For vehicles equipped with large tires or those modified for high horsepower, this type of spool is often a suitable choice when prioritizing pure traction over street manners.

Product descriptions are provided by our supplier partners and may not always be perfectly accurate. Not sure this fits? or call (760) 282-4645 and we’ll verify before you order.

Fitment

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Specifications

BrandUSA Standard Gear
Part NumberZP MINSF9-31
CategoryDrivetrain

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Returns & Fitment

Built for enthusiasts. Every order is backed by our 30 day return window on eligible items. Unused and uninstalled products may be returned with approved RMA and no restocking fees when received in new condition. Orders placed through the MOTORMIA app with a complete build qualify for our Fitment Guarantee — free return shipping if the part doesn’t fit your exact setup. The guarantee covers fit only; installation must follow manufacturer instructions, and we recommend a qualified shop for parts marked Difficulty 4–5.

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Shipping

Orders are processed in 1–3 business days. In stock parts ship promptly from our partner network. Special-order items either aren’t currently stocked or are built to your spec — expect 4–6 weeks. If a part goes on backorder while your order is in the queue, we’ll reach out and work through discounted alternatives together.

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