Ford 4R100 Transmission for Sale | OEM 4-Speed Heavy-Duty Automatic 1998 to 2004

Description

Transmission Background

The Ford 4R100 is the heavy-duty 4-speed automatic that powered the Ford Super Duty line, the Excursion SUV, and E-Series vans from 1998 through 2004. Introduced in 1998 as the direct successor to the E4OD, the 4R100 was specifically engineered to handle the substantial torque output of the 7.3L Power Stroke diesel, alongside the 6.8L Triton V10, the 5.4L Triton V8, and the 6.0L Power Stroke in its earliest applications.

The 4R100 carries a stock torque rating of approximately 535 lb-ft behind the 7.3L Power Stroke and served as the workhorse transmission of one of the most respected diesel pickup combinations ever built. Where the E4OD struggled with 7.3L torque output and developed a reputation for failure, the 4R100 introduced a billet input shaft, a heavy-duty torque converter, an electronic Tow/Haul mode, and revised valve body calibration that improved durability under load significantly.

The 4R100 was replaced by the 5R110W TorqShift starting in 2003 for the 6.0L Power Stroke and fully phased out by 2005. It remains the transmission of choice for 7.3L Power Stroke owners who prefer 4-speed simplicity and the fully mechanical 7.3-to-4R100 combination.

When Replacement Becomes Necessary

• Slipping in 1st or 2nd gear, often clutch pack wear
• Hard 3-to-4 shift or no overdrive engagement, common at high mileage
• Torque converter shudder under lockup load
• Burnt fluid (dark, acrid odor)
• Limp mode with the transmission stuck in 2nd or 3rd
• Cracked case, common on units that have been overpowered or improperly mounted
• Overheating on towing duty, indicating worn pump or contaminated fluid

What to Know Before You Buy

• Diesel versus gas input shaft: the 7.3L Power Stroke and 6.0L Power Stroke 4R100 use a 31-spline input shaft. The gas 6.8L V10 and 5.4L 4R100 use a 26-spline input shaft. These are not interchangeable without changing the input shaft. We confirm spline count on every order.
• Tow/Haul mode wiring: Tow/Haul is electronically controlled by the PCM. The 4R100 itself supports Tow/Haul; the dash button and wiring must be present on the donor truck.
• Early 6.0L 4R100 versus 5R110W: early 2003 6.0L Power Stroke trucks used a 4R100. The 5R110W TorqShift took over later in 2003 and continued through 2007. If you have an early 6.0, a 4R100 is correct. Late 2003 onward 6.0 trucks need a 5R110W.
• 4WD adapter: 4WD 4R100s use a transfer case adapter to mate to the BorgWarner 4406 or 4407 transfer case. We confirm 2WD versus 4WD configuration on every order.
• Banjo bolt seals and cooler line fittings: replace these at install.

4R100 Variants by Engine Pairing

Verified configurations:

What Ships and What Does Not

Direct-Fit Vehicle Applications

Not sure if this fits? Call us. We verify fitment before every order ships.

Search Terms Buyers Use

Used OEM Versus Specialist Rebuild

For a 7.3L Power Stroke Super Duty, Excursion, or E-Series with a tired 4R100, a documented used unit with engine pairing verified and input spline count documented is the cost-effective path. For a high-mileage towing rig or modified diesel build, a specialist rebuild with a billet input shaft, upgraded clutches, and a billet torque converter delivers better long-term value. Rebuilt 4R100s with heavy-duty internals typically run $3,500 to $5,500 plus torque converter from established Ford diesel transmission shops.

Inspection Workflow

• Test stand pressure and shift testing across all 4 forward gears and reverse
• Input shaft spline count verified: 31-spline diesel or 26-spline gas
• Engine pairing confirmed from donor records where available
• Tow/Haul mode wiring presence documented
• 2WD versus 4WD output configuration noted
• External seal and gasket inspection at pan, tailshaft, and pump

Pre-Purchase Buyer Notes

• Match input spline count to your engine: 31-spline behind 7.3L or 6.0L diesel; 26-spline behind V10 or 5.4L V8. Wrong input shaft makes the transmission unusable in your application.
• Plan a fluid flush at installation: refill with Mercon V per Ford spec. Generic ATF accelerates internal wear and may trigger harsh shifts.
• Confirm 4WD versus 2WD: 4WD adapters bolt to a BorgWarner 4406 or 4407 transfer case. Wrong output configuration creates driveshaft mismatch.
• Replace banjo bolt seals and cooler line fittings: cheap insurance against post-install leaks.
• Verify donor truck has Tow/Haul wiring: the 4R100 supports it, but the dash button and PCM programming must be present in your truck for the feature to work.

Why Buy From Part Nests

• Input shaft spline count verified: 31-spline diesel or 26-spline gas documented before payment
• Engine pairing confirmed from donor records where available
• All 4 forward gears and reverse pressure and shift tested before shipment
• 2WD versus 4WD output configuration noted on every order
• No core return required
• Free freight pallet delivery to every state
• 15 day replacement warranty against internal defects
• Call us to speak with someone who knows 4R100 diesel-versus-gas spline differences, 7.3L Power Stroke pairings, and 4WD transfer case adapter requirements