Timken 4278 Differential Pinion Seal - Rear or Rear Outer

Brand Timken 4278
Position Rear
Fits Ford and Lincoln · 265 vehicles

Precision sealing design. Helps prevent lubricant escape and keep contaminants out.

Reinforced outer case. Helps resist installation damage and adds durability.

Ribbed rubber inner diameter. Seals minor imperfections and promotes positive seating.

Cross-references AMS Automotive 4278 and Baldwin 18024 for the same application. See all 2.

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Timken 4278 Differential Pinion Seal

Timken 4278 is a differential pinion seal built for rear axle service on a wide range of Ford, Lincoln, and commercial applications. It uses a precision sealing design to help keep gear lubricant in the axle housing while blocking dirt and debris from entering the seal area.

Key Features

  • Precision sealing design for differential pinion service
  • Reinforced outer case helps resist installation damage
  • Ribbed rubber inner diameter helps seal minor spindle imperfections and improve seating
  • Internal contamination exclusion system helps reduce debris intrusion
  • Vent holes promote lubricant flow around the seal lip to help manage heat

Detailed Description

This Timken differential pinion seal is engineered for rear axle applications where reliable lubricant retention matters. It is used in Ford F-150, Ford Expedition, Ford F-250 Super Duty, Ford F-350 Super Duty, Lincoln Navigator, and related models with the listed ring gear and axle configurations. Timken 4278 is a direct-fit service part for rear differential pinion sealing on many 1998-2024 applications, including rear and rear outer positions where specified.

This part cross-references AMS Automotive 4278 and Baldwin 18024 for the same application.

What It Helps Address

  • Gear oil leakage at the differential pinion area
  • Contamination entering the axle seal surface
  • Heat buildup around the seal lip
  • Seal wear caused by minor surface imperfections
  • Service replacement for worn rear differential pinion seals

Installation Notes and Tips

Verify axle type, ring gear size, and position before installation. Fitment includes rear applications for 9.75-inch and 10.25-inch ring gear setups, plus select 10.5-inch ring gear configurations on Ford Super Duty and van platforms. Confirm the exact vehicle listing for your Ford F-150, Ford Expedition, or Lincoln Navigator before ordering, especially on models with non-limited-slip or specific axle notes.

Quality Assurance

Timken oil and grease seals are built with reinforced sealing construction and contamination control features to support dependable service in driveline applications.

This part fits 265 vehicles
Always verify fitment with your vehicle's VIN if unsure. Submodel & trim restrictions may apply.
YearMakeModelDrive TypePositionNotes
2024FordF-150RWDRear—
2024FordMustangRWDRear—
2024FordTransit-150RWDRear—
2024FordTransit-250RWDRear—
2024FordTransit-350RWDRear—
2024FordTransit-350 HDRWDRear—
2024LincolnNavigator—Rear—
2023FordF-150RWDRear—
2023FordMustangRWDRear—
2023FordTransit-150RWDRear—
2023FordTransit-250RWDRear—
2023FordTransit-350RWDRear—
2023FordTransit-350 HDRWDRear—
2023LincolnNavigator—Rear—
2022FordF-150RWDRear—
2022FordMustangRWDRear—
2022FordTransit-150RWDRear—
2022FordTransit-250RWDRear—
2022FordTransit-350RWDRear—
2022FordTransit-350 HDRWDRear—
2022LincolnNavigator—Rear—
2021FordF-150RWDRear—
2021FordMustangRWDRear—
2021FordTransit-150RWDRear—
2021FordTransit-250RWDRear—
2021FordTransit-350RWDRear—
2021FordTransit-350 HDRWDRear—
2021LincolnNavigator—Rear—
2020FordExpedition—Rear—
2020FordF-150—Rear—
2020FordMustang—Rear—
2020FordTransit-150RWDRear—
2020FordTransit-250RWDRear—
2020FordTransit-350RWDRear—
2020FordTransit-350 HDRWDRear—
2020LincolnNavigator—RearFits 9.75" Ring Gear for Differential Pinion Bearing.
2019FordExpedition—Rear—
2019FordF-150—Rear—
2019FordMustang—Rear—
2019FordTransit-150—Rear—
2019FordTransit-250—Rear—
2019FordTransit-350—Rear—
2019FordTransit-350 HD—Rear—
2019LincolnNavigator—RearFits 9.75" Ring Gear for Differential Pinion Bearing.
2018FordExpedition—Rear—
2018FordF-150—Rear—
2018FordMustang—Rear—
2018FordTransit-150—Rear—
2018FordTransit-250—Rear—
2018FordTransit-350—Rear—
2018FordTransit-350 HD—Rear—
2018LincolnNavigator—RearFits 9.75" Ring Gear for Differential Pinion Bearing.
2017FordExpedition—Rear—
2017FordF-150—Rear—
2017FordMustang—Rear—
2017FordTransit-150—Rear—
2017FordTransit-250—Rear—
2017FordTransit-350—Rear—
2017FordTransit-350 HD—Rear—
2017LincolnNavigator—RearFits 9.75" Ring Gear for Differential Pinion Bearing.
2016FordExpedition—Rear—
2016FordF-150—Rear—
2016FordMustang—Rear—
2016FordTransit-150—Rear—
2016FordTransit-250—Rear—
2016FordTransit-350—Rear—
2016FordTransit-350 HD—Rear—
2016LincolnNavigator—RearFits 9.75" Ring Gear for Differential Pinion Bearing.
2015FordExpedition—Rear—
2015FordF-150—Rear—
2015FordMustang—Rear—
2015FordTransit-150—Rear—
2015FordTransit-250—Rear—
2015FordTransit-350—Rear—
2015FordTransit-350 HD—Rear—
2015LincolnNavigator—RearFits 9.75" Ring Gear for Differential Pinion Bearing.
2014FordExpedition—Rear—
2014FordF-150—Rear—
2014FordF-150—RearFor Non-Limited Slip Differentials with a 9.75" Ring Gear.
2014LincolnNavigator—RearFits 9.75" Ring Gear for Differential Pinion Bearing.
2013FordExpedition—Rear—
2013FordF-150—Rear—
2013FordF-150—RearFor Non-Limited Slip Differentials with a 9.75" Ring Gear.
2013LincolnNavigator—RearFits 9.75" Ring Gear for Differential Pinion Bearing.
2012FordExpedition—Rear—
2012FordF-150—RearFor Non-Limited Slip Differentials with a 9.75" Ring Gear.
2012FordF-150—RearFits 9.75" Ring Gear for Differential Pinion Bearing.
2012LincolnNavigator—RearFits 9.75" Ring Gear for Differential Pinion Bearing.
2011FordExpedition—Rear—
2011FordF-150—RearFor Non-Limited Slip Differentials with a 9.75" Ring Gear.
2011FordF-150—RearFits 9.75" Ring Gear for Differential Pinion Bearing.
2011FordF-250 Super Duty—RearFits vehicles with 10.5 inch Ring Gear and Automatic Transmission Output Shaft Bearing.
2011LincolnNavigator—RearFits 9.75" Ring Gear for Differential Pinion Bearing.
2010FordExpedition—Rear—
2010FordF-150—RearFor Non-Limited Slip Differentials with a 9.75" Ring Gear.
2010FordF-150—RearFits 9.75" Ring Gear for Differential Pinion Bearing.
2010FordF-250 Super Duty—Rear—
2010FordF-350 Super Duty—RearFits vehicles with 10.5 inch Ring Gear and Automatic Transmission Output Shaft Bearing.
2010LincolnNavigator—RearFits 9.75" Ring Gear for Differential Pinion Bearing.
2009FordExpedition—Rear—
2009FordF-150—RearFor Non-Limited Slip Differentials with a 9.75" Ring Gear.
2009FordF-150—RearFits 9.75" Ring Gear for Differential Pinion Bearing.
2009FordF-250 Super Duty—Rear—
2009FordF-350 Super Duty—RearFits vehicles with 10.5 inch Ring Gear and Automatic Transmission Output Shaft Bearing.
2009LincolnNavigator—RearFits 9.75" Ring Gear for Differential Pinion Bearing.
2008FordE-250—RearFits vehicles with 10.5 inch Ring Gear and Automatic Transmission Output Shaft Bearing.
2008FordExpedition—RearFits 9.75" Ring Gear for Differential Pinion Bearing.
2008FordF-150—RearFor Non-Limited Slip Differentials with a 9.75" Ring Gear.
2008FordF-150—RearFits 9.75" Ring Gear for Differential Pinion Bearing.
2008FordF-150—RearNon-Limited Slip Differential with a Ring Gear size of 10.25 inches.
2008FordF-150—Rear10.25 in. Ring Gear Differential Pinion Race
2008FordF-250 Super Duty—RearFits vehicles with 10.5 inch Ring Gear and Automatic Transmission Output Shaft Bearing.
2008FordF-350 Super Duty—RearFits vehicles with 10.5 inch Ring Gear and Automatic Transmission Output Shaft Bearing.
2008LincolnMark LT—RearFits 9.75" Ring Gear for Differential Pinion Bearing.
2008LincolnMark LT—Rear10.25 in. Ring Gear Differential Pinion Race
2008LincolnNavigator—RearFits 9.75" Ring Gear for Differential Pinion Bearing.
2007FordE-150—RearFor Non-Limited Slip Differentials with a 9.75" Ring Gear.
2007FordE-250—RearFits vehicles with 10.5 inch Ring Gear and Automatic Transmission Output Shaft Bearing.
2007FordExpedition—RearFits 9.75" Ring Gear for Differential Pinion Bearing.
2007FordF-150—RearFor Non-Limited Slip Differentials with a 9.75" Ring Gear.
2007FordF-150—RearFits 9.75" Ring Gear for Differential Pinion Bearing.
2007FordF-150—RearNon-Limited Slip Differential with a Ring Gear size of 10.25 inches.
2007FordF-250 Super Duty—RearFits vehicles with 10.5 inch Ring Gear and Automatic Transmission Output Shaft Bearing.
2007FordF-350 Super Duty—RearFits vehicles with 10.5 inch Ring Gear and Automatic Transmission Output Shaft Bearing.
2007FordF-350 Super Duty—Rear OuterDual Rear Wheels - Narrow Frame
2007LincolnMark LT—RearFits 9.75" Ring Gear for Differential Pinion Bearing.
2007LincolnMark LT—Rear10.25 in. Ring Gear Differential Pinion Race
2007LincolnNavigator—RearFits 9.75" Ring Gear for Differential Pinion Bearing.
2006FordE-150—RearFor Non-Limited Slip Differentials with a 9.75" Ring Gear.
2006FordExpedition—RearFits 9.75" Ring Gear for Differential Pinion Bearing.
2006FordF-150—RearFor Non-Limited Slip Differentials with a 9.75" Ring Gear.
2006FordF-150—RearNon-Limited Slip Differential with a Ring Gear size of 10.25 inches.
2006FordF-250 Super Duty—Rear—
2006FordF-350 Super Duty—Rear OuterDual Rear Wheels - Narrow Frame
2006FordF-350 Super Duty—Rear—
2006FordF-350 Super Duty—RearFits vehicles with 10.5 inch Ring Gear and Automatic Transmission Output Shaft Bearing.
2006LincolnMark LT—RearFits 9.75" Ring Gear for Differential Pinion Bearing.
2006LincolnMark LT—Rear10.25 in. Ring Gear Differential Pinion Race
2006LincolnNavigator—RearFits 9.75" Ring Gear for Differential Pinion Bearing.
2006LincolnNavigator—Rear10.25 in. Ring Gear Differential Pinion Race
2005FordE-150—RearFor Non-Limited Slip Differentials with a 9.75" Ring Gear.
2005FordE-150 Club Wagon—RearFor Non-Limited Slip Differentials with a 9.75" Ring Gear.
2005FordE-350 Club Wagon—RearFits vehicles with 10.5 inch Ring Gear and Automatic Transmission Output Shaft Bearing.
2005FordE-350 Super Duty—RearFits vehicles with 10.5 inch Ring Gear and Automatic Transmission Output Shaft Bearing.
2005FordExcursion—RearFits vehicles with 10.5 inch Ring Gear and Automatic Transmission Output Shaft Bearing.
2005FordExpedition—RearFits 9.75" Ring Gear for Differential Pinion Bearing.
2005FordF-150—RearFor Non-Limited Slip Differentials with a 9.75" Ring Gear.
2005FordF-150—RearNon-Limited Slip Differential with a Ring Gear size of 10.25 inches.
2005FordF-250 Super Duty—Rear—
2005FordF-350 Super Duty—Rear OuterDual Rear Wheels - Narrow Frame
2005FordF-350 Super Duty—RearFits vehicles with 10.5 inch Ring Gear and Automatic Transmission Output Shaft Bearing.
2005LincolnNavigator—RearFits 9.75" Ring Gear for Differential Pinion Bearing.
2004FordE-150—RearFor Non-Limited Slip Differentials with a 9.75" Ring Gear.
2004FordE-150 Club Wagon—RearFor Non-Limited Slip Differentials with a 9.75" Ring Gear.
2004FordE-350 Club Wagon—RearFits vehicles with 10.5 inch Ring Gear and Automatic Transmission Output Shaft Bearing.
2004FordE-350 Super Duty—RearFits vehicles with 10.5 inch Ring Gear and Automatic Transmission Output Shaft Bearing.
2004FordExcursion—RearFits vehicles with 10.5 inch Ring Gear and Automatic Transmission Output Shaft Bearing.
2004FordExpedition—RearFits 9.75" Ring Gear for Differential Pinion Bearing.
2004FordF-150—RearFor Non-Limited Slip Differentials with a 9.75" Ring Gear.
2004FordF-150—RearFits 9.75" Ring Gear for Differential Pinion Bearing.
2004FordF-150—RearNon-Limited Slip Differential with a Ring Gear size of 10.25 inches.
2004FordF-150—Rear10.25 in. Ring Gear Differential Pinion Race
2004FordF-150 Heritage—RearFor Non-Limited Slip Differentials with a 9.75" Ring Gear.
2004FordF-150 Heritage—RearNon-Limited Slip Differential with a Ring Gear size of 10.25 inches.
2004FordF-250 Super Duty—RearNon Dana Axle
2004FordF-350 Super Duty—RearFits vehicles with 10.5 inch Ring Gear and Automatic Transmission Output Shaft Bearing.
2004FordF-350 Super Duty—Rear OuterNon Dana Axle
2004LincolnNavigator—RearFits 9.75" Ring Gear for Differential Pinion Bearing.
2003FordE-150—RearFor Non-Limited Slip Differentials with a 9.75" Ring Gear.
2003FordE-150 Club Wagon—RearFor Non-Limited Slip Differentials with a 9.75" Ring Gear.
2003FordE-350 Club Wagon—RearFits vehicles with 10.5 inch Ring Gear and Automatic Transmission Output Shaft Bearing.
2003FordExcursion—RearFits vehicles with 10.5 inch Ring Gear and Automatic Transmission Output Shaft Bearing.
2003FordExpedition—RearFits 9.75" Ring Gear for Differential Pinion Bearing.
2003FordF-150—RearFor Non-Limited Slip Differentials with a 9.75" Ring Gear.
2003FordF-150—RearFits 9.75" Ring Gear for Differential Pinion Bearing.
2003FordF-150—Rear10.25 in. Ring Gear Differential Pinion Race
2003FordF-250 Super Duty—RearNon Dana Axle
2003FordF-350 Super Duty—RearFits vehicles with 10.5 inch Ring Gear and Automatic Transmission Output Shaft Bearing.
2003FordF-350 Super Duty—Rear OuterNon Dana Axle
2003LincolnAviator—RearFits 9.75" Ring Gear for Differential Pinion Bearing.
2003LincolnNavigator—RearFits 9.75" Ring Gear for Differential Pinion Bearing.
2002FordE-150 Econoline—RearFor Non-Limited Slip Differentials with a 9.75" Ring Gear.
2002FordE-150 Econoline Club Wagon—RearFor Non-Limited Slip Differentials with a 9.75" Ring Gear.
2002FordE-350 Econoline Club Wagon—RearFits vehicles with 10.5 inch Ring Gear and Automatic Transmission Output Shaft Bearing.
2002FordExcursion—RearFits vehicles with 10.5 inch Ring Gear and Automatic Transmission Output Shaft Bearing.
2002FordExpedition—RearFits 9.75" Ring Gear for Differential Pinion Bearing.
2002FordF-150—RearFor Non-Limited Slip Differentials with a 9.75" Ring Gear.
2002FordF-150—RearFits 9.75" Ring Gear for Differential Pinion Bearing.
2002FordF-150—Rear10.25 in. Ring Gear Differential Pinion Race
2002FordF-250 Super Duty—RearNon Dana Axle
2002FordF-350 Super Duty—RearFits vehicles with 10.5 inch Ring Gear and Automatic Transmission Output Shaft Bearing.
2002FordF-350 Super Duty—Rear OuterNon Dana Axle
2002LincolnBlackwood—RearFits 9.75" Ring Gear for Differential Pinion Bearing.
2002LincolnNavigator—RearFits 9.75" Ring Gear for Differential Pinion Bearing.
2001FordE-150 Econoline—RearFor Non-Limited Slip Differentials with a 9.75" Ring Gear.
2001FordE-150 Econoline Club Wagon—RearFor Non-Limited Slip Differentials with a 9.75" Ring Gear.
2001FordE-350 Econoline Club Wagon—RearFits vehicles with 10.5 inch Ring Gear and Automatic Transmission Output Shaft Bearing.
2001FordExcursion—RearFits vehicles with 10.5 inch Ring Gear and Automatic Transmission Output Shaft Bearing.
2001FordExpedition—RearFits 9.75" Ring Gear for Differential Pinion Bearing.
2001FordF-150—RearFor Non-Limited Slip Differentials with a 9.75" Ring Gear.
2001FordF-150—RearFits 9.75" Ring Gear for Differential Pinion Bearing.
2001FordF-150—Rear10.25 in. Ring Gear Differential Pinion Race
2001FordF-250 Super Duty—RearNon Dana Axle
2001FordF-350 Super Duty—RearFits vehicles with 10.5 inch Ring Gear and Automatic Transmission Output Shaft Bearing.
2001FordF-350 Super Duty—Rear OuterNon Dana Axle
2001LincolnNavigator—RearFits 9.75" Ring Gear for Differential Pinion Bearing.
2000FordE-150 Econoline—RearFor Non-Limited Slip Differentials with a 9.75" Ring Gear.
2000FordE-150 Econoline Club Wagon—RearFor Non-Limited Slip Differentials with a 9.75" Ring Gear.
2000FordE-350 Econoline Club Wagon—RearFits vehicles with 10.5 inch Ring Gear and Automatic Transmission Output Shaft Bearing.
2000FordExcursion—RearFits vehicles with 10.5 inch Ring Gear and Automatic Transmission Output Shaft Bearing.
2000FordExpedition—RearFits 9.75" Ring Gear for Differential Pinion Bearing.
2000FordF-150—RearFor Non-Limited Slip Differentials with a 9.75" Ring Gear.
2000FordF-150—RearFits 9.75" Ring Gear for Differential Pinion Bearing.
2000FordF-150—Rear10.25 in. Ring Gear Differential Pinion Race
2000FordF-250 Super Duty—RearNon Dana Axle
2000FordF-350 Super Duty—RearFits vehicles with 10.5 inch Ring Gear and Automatic Transmission Output Shaft Bearing.
2000FordF-350 Super Duty—Rear OuterNon Dana Axle
2000LincolnNavigator—RearFits 9.75" Ring Gear for Differential Pinion Bearing.
1999FordE-350 Econoline Club Wagon—RearFits vehicles with 10.5 inch Ring Gear and Automatic Transmission Output Shaft Bearing.
1999FordF-350 Super Duty—RearFits vehicles with 10.5 inch Ring Gear and Automatic Transmission Output Shaft Bearing.
1999LincolnNavigator—RearFits 9.75" Ring Gear for Differential Pinion Bearing.
1998FordE-250 Econoline—Rear10.5 in. Ring Gear - From 1/1998
1998FordE-350 Econoline—Rear10.25 in., 10.5 in. Ring Gear
1998FordE-350 Econoline Club Wagon—Rear10.25 in., 10.5 in. Ring Gear
1998FordF-250—Rear10.5 in. Ring Gear - From 1/1998
1998LincolnNavigator—RearFits 9.75" Ring Gear for Differential Pinion Bearing.
1997FordE-350 Econoline—Rear10.25 in., 10.5 in. Ring Gear
1997FordE-350 Econoline Club Wagon—Rear10.25 in., 10.5 in. Ring Gear
1997FordF-350—Rear10.25 in., 10.5 in. Ring Gear
1996FordE-350 Econoline—Rear10.25 in., 10.5 in. Ring Gear
1996FordE-350 Econoline Club Wagon—Rear10.25 in., 10.5 in. Ring Gear
1996FordF-350—Rear10.25 in., 10.5 in. Ring Gear
1995FordE-350 Econoline—Rear10.25 in., 10.5 in. Ring Gear
1995FordE-350 Econoline Club Wagon—Rear10.25 in., 10.5 in. Ring Gear
1995FordF-350—Rear10.25 in., 10.5 in. Ring Gear
1994FordE-350 Econoline—Rear10.25 in., 10.5 in. Ring Gear
1994FordE-350 Econoline Club Wagon—Rear10.25 in., 10.5 in. Ring Gear
1994FordF-350—Rear10.25 in., 10.5 in. Ring Gear
1993FordE-350 Econoline—Rear10.25 in., 10.5 in. Ring Gear
1993FordE-350 Econoline Club Wagon—Rear10.25 in., 10.5 in. Ring Gear
1993FordF-350—Rear10.25 in., 10.5 in. Ring Gear
1992FordE-350 Econoline—Rear10.25 in., 10.5 in. Ring Gear
1992FordE-350 Econoline Club Wagon—Rear10.25 in., 10.5 in. Ring Gear
1992FordF-350—Rear10.25 in., 10.5 in. Ring Gear
1991FordE-350 Econoline—Rear10.25 in., 10.5 in. Ring Gear
1991FordE-350 Econoline Club Wagon—Rear10.25 in., 10.5 in. Ring Gear
1991FordF-350—Rear10.25 in., 10.5 in. Ring Gear
1990FordE-350 Econoline—Rear10.25 in., 10.5 in. Ring Gear
1990FordE-350 Econoline Club Wagon—Rear10.25 in., 10.5 in. Ring Gear
1990FordF-350—Rear10.25 in., 10.5 in. Ring Gear
1989FordE-350 Econoline—Rear10.25 in., 10.5 in. Ring Gear
1989FordE-350 Econoline Club Wagon—Rear10.25 in., 10.5 in. Ring Gear
1989FordF-350—Rear10.25 in., 10.5 in. Ring Gear
1988FordE-350 Econoline—Rear10.25 in., 10.5 in. Ring Gear
1988FordE-350 Econoline Club Wagon—Rear10.25 in., 10.5 in. Ring Gear
1988FordF-350—Rear10.25 in., 10.5 in. Ring Gear
1987FordE-350 Econoline—Rear10.25 in., 10.5 in. Ring Gear
1987FordE-350 Econoline Club Wagon—Rear10.25 in., 10.5 in. Ring Gear
1987FordF-350—Rear10.25 in., 10.5 in. Ring Gear
1986FordE-350 Econoline—Rear10.25 in., 10.5 in. Ring Gear
1986FordE-350 Econoline Club Wagon—Rear10.25 in., 10.5 in. Ring Gear
1986FordF-350—Rear10.25 in., 10.5 in. Ring Gear
1985FordE-350 Econoline—Rear10.25 in., 10.5 in. Ring Gear
1985FordE-350 Econoline Club Wagon—Rear10.25 in., 10.5 in. Ring Gear
1985FordF-350—Rear10.25 in., 10.5 in. Ring Gear
Directly replaces or cross-references 2 part numbers
Cross-reference numbers are provided for identification purposes only. Always confirm fitment before ordering.
AMS Automotive — 4278Baldwin — 18024