Yukon Gear High Performance Gear Set For Ford 8.8in in a 3.73 Ratio

Yukon Gear Ring and Pinion Set for Ford 8.8-Inch Differential in 3.73 Ratio

The YG F8.8-373 from Yukon Gear and Axle is a high-performance ring and pinion gear set built for the Ford 8.8-inch rear differential in a 3.73 gear ratio. The Ford 8.8 axle is one of the most common rear differentials in the F-150, Mustang, Explorer, Bronco, Expedition, Ranger, and many Lincoln, Mercury, and Mazda vehicles from 1978 through 2014. The YG F8.8-373 is engineered to restore or upgrade the gearing in these vehicles, offering an excellent balance between highway fuel efficiency and the added torque response that comes with bigger tires or performance engine upgrades. Yukon machines this set using high-grade steel alloy with a precision tooth profile verified in two in-house quality labs. The 3.73 ratio in the YG F8.8-373 is a popular choice for light truck and Mustang owners who want noticeable performance gains without sacrificing too much at highway RPM.

Key Features and Benefits

• 3.73 Gear Ratio: Excellent balance of highway efficiency and performance response for street and mild off-road use
• Ford 8.8-Inch Fitment: Direct replacement for one of the most widely used rear axles in Ford, Lincoln, Mercury, and Mazda vehicles
• 28 or 31-Spline Pinion: Matches standard Ford 8.8 carrier specifications across the production range
• High-Grade Steel Alloy: Premium material machined to tight tolerances for long-term reliability
• Advanced Surface Finish: Reduced friction and heat buildup under sustained towing and performance driving
• Dual Lab Testing: Every set verified for tooth geometry and load capacity before shipment
• Y.E.S. Plan Eligible: Optional lifetime no-questions-asked warranty available

Fitment

Specs

What Is Included

• Ring gear
• Pinion gear
• Pinion nut

Frequently Asked Questions

• Q: What vehicles does the YG F8.8-373 fit?
  A: The YG F8.8-373 fits Ford 8.8-inch rear differentials in the F-150, Mustang, Explorer, Bronco, Expedition, Ranger, Crown Victoria, and many Lincoln, Mercury, and Mazda vehicles from 1978 through 2014.
• Q: What spline count does this pinion use?
  A: Pre-1999 Ford 8.8 applications use a 28-spline pinion. 1999-and-newer applications use a 31-spline pinion. The YG F8.8-373 is available to match your carrier configuration; confirm before ordering.
• Q: Is 3.73 a good ratio for daily driving with larger tires?
  A: Yes. The 3.73 ratio in the YG F8.8-373 is a popular balance point. It provides noticeable torque improvement with 31-to-33-inch tires while keeping highway RPM at a comfortable level for daily use.
• Q: Does a carrier break apply to this ratio?
  A: The Ford 8.8 differential uses different carrier sizes above and below approximately 3.73. Verify whether your application needs a new carrier when switching from a significantly lower or higher ratio.
• Q: Can my factory warranty be voided under Magnuson-Moss?
  A: No. The Magnuson-Moss Warranty Act prevents dealers from voiding your warranty solely due to aftermarket installation. They must show a direct causal link between the YG F8.8-373 and the failure.
• Q: What other parts will I need?
  A: Plan on a Ford 8.8 master install kit with bearings, seals, shims, and a pinion seal. Gear marking compound and a dial indicator are also required for proper setup.
• Q: What warranty comes with the YG F8.8-373?
  A: One year against manufacturing defects with the option to upgrade to the Yukon Y.E.S. lifetime plan.
• Q: Is professional installation recommended?
  A: Yes. Proper differential setup requires precise pinion depth, backlash, and pattern verification. These steps protect the YG F8.8-373 and ensure long-term performance.

Installation Instructions

1. Safely support the vehicle and drain the rear differential gear oil.
2. Mark and remove the driveshaft and rear axle shafts.
3. Pull the differential cover and clean the housing.
4. Record existing ring gear backlash and pinion preload.
5. Remove bearing caps, carrier, and old ring and pinion set.
6. Install new pinion bearings from the master install kit on the YG F8.8-373 pinion.
7. Shim pinion depth to achieve correct tooth contact using a dial indicator.
8. Press the new ring gear onto the carrier and torque ring gear bolts in a cross pattern to spec.
9. Install carrier, set bearing preload, and adjust backlash to 0.008 to 0.012 inch for the Ford 8.8.
10. Verify contact pattern with marking compound; adjust as needed.
11. Seal cover with RTV or gasket and fill with the specified Ford 8.8 gear oil.
12. Reinstall axle shafts, driveshaft, and wheels, torquing all fasteners to specification.
13. Follow the Yukon break-in procedure before sustained performance or towing use.

Proposition 65 Warning: This product can expose you to chemicals including lead, which is known to the State of California to cause cancer and birth defects or other reproductive harm. For more information go to www.P65Warnings.ca.gov.