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Yukon Gear & Axle YP FSF9-31 Steel Spool for Ford 9 Inch 31 Spline

(Ford F-150 1975-87, Mustang 1965-73, Bronco 1966-86, Thunderbird 1955-79, Maverick 1970-77, Galaxie 500 1968-74, F-100 1957-83 + 18 more models)

Part of: Yukon Gear & Axle Steel Spool Ford 9 Inch

Other options in this family: Yukon Gear & Axle YP FSF9-35 Yukon Gear & Axle YP FSF9-33

Manufacturer

Picture for manufacturer Yukon Gear & Axle

Part Number

YP FSF9-31
7 reviews
Sale Price

$200.33

In Stock (10+)

delivery box

Usually delivered within 2 days

free shipping

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Live-in-stock inventory

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Fitment guaranteed

Fitment guaranteed

Product Details

The Yukon Gear & Axle YP FSF9-31 is a high-performance steel spool designed specifically for Ford 9-inch differentials with 31 spline axles. This 2-1/8" deck steel spool utilizes 1.785" journal bearings and is engineered to deliver 100% power to both tires at all times, making it ideal for drag racing, rock crawling, and other high-performance off-road applications.

Key Features:

  • Precision-machined steel construction for maximum strength and durability
  • 2-1/8" deck height for proper differential fitment
  • Compatible with 31 spline axles
  • Uses 1.785" journal bearings
  • Provides full power transfer to both wheels simultaneously
  • Cost-effective alternative to selectable lockers

Important: Spools are designed for off-road and competition use only and are not recommended for street-driven vehicles due to the constant locked differential action, which can cause tire wear and handling issues during turns. Backed by Yukon's one-year warranty against manufacturing defects.

Products specifications

Fits

Ford F-150 1975-87, Mustang 1965-73, Bronco 1966-86, Thunderbird 1955-79, Maverick 1970-77, Galaxie 500 1968-74, F-100 1957-83, Fairlane 1957-70, Ranchero 1957-79, Falcon 1960-70, Galaxie 1959-67, Gran Torino 1972-76 + 13 more models

Axle Type

Ford 9 in.

Spline Quantity

31

Position

Rear

Prop 65

No

I just received my Knn filter. Shipment was on time. The box look beat up and deformed with a lot of tapes but the filter seems to be in good condition.

Great Prices! and Great Customer Service thanks again!

Quick-n-easy

Fantastic company! Great selection for every vehicle and fast shipping! I will definitely shop here again.

Fast ship, great price. I will purchase merchandise from them again.

Excellent service. I called in Monday for a hard to find item which I had ordered from several other online shops who despite saying were In Stock online were not actually in stock at all and the orders were canceled after waiting a week to find out. They had the item in stock as listed on their website and shipped the next day. The price was the cheapest of anyone who actually had the item in stock by a substantial amount.

Best price anywhere for a brand name item. Fast inexpensive shipping!

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