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Drivetrain› Differentials and Rear-End Components

Zumbrota Drivetrain

Steel Spool

Name: Steel Spool
Brand: Zumbrota Drivetrain
SKU: YP FSM20-3-29

$501.64 $478.89 Save $22.75

SKU: YP FSM20-3-29

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Overview

The Yukon steel spool is a differential component designed to convert a diff to 100% lockup. It installs in place of the differential carrier assembly.

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The Yukon steel spool is a cost-effective differential component engineered to convert a standard differential to a 100% locked setup, ensuring both wheels receive constant traction. This spool directly replaces the existing differential carrier assembly, making installation straightforward. It is specifically designed to fit the AMC Model 20 differential and is compatible with gear ratios of 3.08 and numerically higher. This differential spool is intended exclusively for dedicated off-road and drag racing vehicles. It is not recommended for street-driven vehicles due to its nature of providing 100% traction to both wheels at all times, which can lead to tire scrub and reduced maneuverability in normal driving conditions.

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

Brand	Zumbrota Drivetrain
Part Number	YP FSM20-3-29
Category	Drivetrain

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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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