Home› Driveline and Axles > Gaskets and Sealing Systems› National 6930 Differential Pinion Seal - Rear
National 6930 Differential Pinion Seal - RearOE Quality 60-Day Returns
Part #: 6930

National 6930 Differential Pinion Seal - Rear

Rear
6 vehicles fit this part
Select your vehicle to confirm fitment
Verify this part fits before purchasing — free returns if it doesn't
$21.57Free Shipping
Free ShippingNo Cost to Continental U.S.
Free Returns*Wrong fit? No cost
60-Day ReturnsMoney back guarantee
*Free return shipping only qualifies if our fitment verification tool is used.
In Stock · Ready To Ship Most orders ship same-day if ordered before 1pm CST.
OE Direct Replacement — Bolt-on fit, no modifications needed
Fitment: Edsel, Ford, and Mercury, Bermuda, Citation, Corsair, Pacer, Ranger, Roundup, Villager, Club, Country Sedan, Country Squire, Courier Sedan Delivery, Custom 300, Del Rio Wagon, F-100, Fairlane, Ranch Wagon, Ranchero, Skyliner, Sunliner, Thunderbird, Victoria, Colony Park, Commuter, Medalist, Montclair, Monterey, Park Lane, Voyager, Custom, and Turnpike Cruiser
Easy Returns — Return within 60 days for a full refund
Fast Shipping — Most orders ship same business day before 1pm CST
Not what you need? See all Differential Pinion Seal options

National 6930 Differential Pinion Seal

National 6930 is a differential pinion seal built for rear axle sealing applications that require a precise shaft and housing fit. It is specified for 1957-1958 Ford F-100, Ford Thunderbird, and Mercury Colony Park rear applications with Ford axle and 9-inch ring gear configurations.

Key Features

  • Part number 6930 differential pinion seal for rear driveline sealing
  • Inside diameter: 1.812 in. / 46.020 mm
  • Outside diameter: 4.128 in. / 104.850 mm
  • Thickness/width: 0.746 in. / 18.950 mm
  • Housing bore: 4.123 in. / 104.720 mm
  • Leather seal material with Oil Seal part description
  • Series 6000, Type 21

Detailed Description

National 6930 is a rear differential pinion seal engineered around exact dimensional requirements for older Ford axle assemblies. The seal’s 1.812-inch shaft diameter, 4.128-inch outside diameter, and 0.746-inch width help it match the housing and pinion interface used in 1957-1958 Ford F-100, Ford Thunderbird, and Mercury Colony Park rear differentials. National has supplied sealing solutions for more than 75 years, and this part reflects that focus on dimensional accuracy and drivetrain sealing performance. This part cross-references Dorman - HELP 46100 and Davico Mfg 18276 for the same application.

What It Helps Address

  • Rear differential oil seepage at the pinion seal area
  • Gear oil loss from a worn or hardened seal
  • Contamination around the pinion yoke and housing bore
  • Sealing issues on Ford axle assemblies with a 9-inch ring gear
  • Fitment concerns on 1957-1958 Ford F-100, Ford Thunderbird, and Mercury Colony Park rear applications

Installation Notes and Tips

Verify the housing bore, shaft diameter, and seal width before installation to confirm the correct match for the axle assembly. Inspect the pinion yoke surface for wear or grooves that can affect sealing performance, and clean the housing bore thoroughly before pressing the seal into place. Confirm rear position fitment and Ford axle configuration against the vehicle’s service information before final assembly. Part number 6930 is listed for 1957-1958 Ford F-100 rear, 1957-1958 Ford Thunderbird rear, and 1957-1958 Mercury Colony Park rear applications with the specified 9-inch ring gear and axle notes.

Quality Assurance

National is a long-established sealing brand with a history of supplying premium sealing solutions for drivetrain and axle service. The 6930 seal is built to the listed dimensions and material specification for consistent fitment in the confirmed applications.

BrandNational
Part Number6930
Housing Bore (Inch)4.123
Housing Bore (MM)104.720
Inside Diameter1.812
Inside Diameter46.020
MaterialLeather
Outside Diameter4.128
Outside Diameter104.850
Outside Diameter (Inch)4.128
Outside Diameter (mm)104.850
Part DescriptionOil Seal
Series6000
Shaft (Inch)1.812
Shaft (MM)46.020
Thickness0.746
Thickness18.950
Type21
Unit of DimensionInch
Width (Inch)0.746
Width (mm)18.950

This part fits 6 vehicles. Search below:

YearMakeModelPositionNotes
1958FordF-100Rear1st Design; with 9 (in) Ring Gear; with 0.746 (in) Width; with Ford Axle; 4.128 (in) Outside Diameter
1958FordThunderbirdRear1st Design; with 9 (in) Ring Gear; with 0.746 (in) Width; with Ford Axle; 4.128 (in) Outside Diameter
1958MercuryColony ParkRear1st Design; with 9 (in) Ring Gear; with 0.746 (in) Width; with Ford Axle; 4.128 (in) Outside Diameter
1957FordF-100Rearwith 9 (in) Ring Gear; with Ford Axle
1957FordThunderbirdRearwith 9 (in) Ring Gear; with Ford Axle
1957MercuryColony ParkRearwith 9 (in) Ring Gear; with Ford Axle

* Always verify fitment with your vehicle's VIN if unsure. Submodel & trim restrictions may apply.

This part directly replaces or is cross-referenced with the following part numbers:

182762067212206721329227461006930B7A4676AB8A4676AT1762WAA4676WAA4676BWAT4676AWAT4676A3XW1652

Cross-reference numbers are provided for identification purposes only. Always confirm fitment before ordering.