4R100 Transmission Rebuild & Repair in Glendale, AZ (Ford)

Sun West Transmissions — Glendale, AZ. Free estimates, honest diagnosis and a 3-year / 40,000-mile warranty on qualifying rebuilds and replacements.

The Ford 4R100 is the updated successor to the E4OD, and it became the go-to automatic behind the 7.3L Power Stroke diesel, the 6.8L V10 and the 5.4L V8 in the first generation of Super Duty trucks. It also served in the Excursion and E-Series vans. Many of these trucks are still pulling trailers and hauling equipment across Maricopa County, and a healthy 4R100 is a big part of why they keep going.

At Sun West Transmissions in Glendale, the 4R100 is a familiar unit. We repair and rebuild them for work trucks, diesel enthusiasts and RV owners throughout the West Valley.

4R100 Applications

The 4R100 was used from the late 1990s into the mid-2000s, depending on the model and engine. Typical applications include:

• Ford F-250 and F-350 Super Duty with the 7.3L Power Stroke, V10 or 5.4L
• Ford Excursion
• Ford E-Series vans and cutaways, including diesel models
• Some F-150 heavy-duty and older F-250 light-duty trucks

When the 6.0L Power Stroke arrived, Ford moved Super Duty diesel trucks to the five-speed TorqShift. If you are not sure which unit your truck has, we will check. Our 5R110W TorqShift page covers the newer transmission.

What Usually Goes Wrong

The 4R100 is tough, but it is not immune to heat and age. The 7.3L diesel makes strong low-end torque, and when it is paired with a heavy trailer and an Arizona summer, transmission temperatures climb quickly.

Burnt Clutches and Bands

Heat breaks down fluid, which leads to glazed clutches and worn bands. Symptoms include slipping on the 2-3 shift, flaring into overdrive and a general soft feel under load.

Overdrive and Coast Clutch Issues

Problems in the overdrive section can cause the truck to lose fourth gear, drop out of overdrive under load or engage harshly. These issues often show up first when towing on the freeway.

EPC Solenoid and Pressure Problems

The electronic pressure control solenoid regulates line pressure. If it sticks or fails, shifts may become very harsh or very soft, and the transmission can be damaged from low pressure. We test the circuit and look at pressure before blaming internal parts.

Torque Converter Wear

The converter clutch takes a beating in diesel trucks. A worn converter can cause shudder, high temperatures and debris in the fluid. Learn more on our torque converter replacement page.

Leaks

Front pump seals, pan gaskets, cooler line fittings and the rear seal can all leak on older units. Low fluid accelerates every other problem on this list.

How We Check a 4R100

Our diagnosis covers fluid level and condition, codes and live data, solenoid and sensor testing, line pressure checks and a road test under realistic load when possible. We also look at the cooler, cooler lines and engine cooling system, because a weak radiator can push the transmission over the edge. See our radiator replacement page if your truck runs hot.

4R100 Rebuild at Sun West

A full rebuild means taking the transmission completely apart, cleaning and inspecting every component, and replacing every soft part along with worn hard parts. We address known weak areas with updated components where they make sense, service or replace the converter, and flush the cooler circuit before reinstalling.

• New clutches, bands, steels, seals, gaskets and filter
• Bushings, thrust washers and hard parts as needed
• Valve body cleaning, inspection and updates
• Torque converter inspection or replacement
• Cooler flush, fill and road test

Ask us about upgrades for towing or for diesels with added power. Qualifying rebuilds include our 3-year / 40,000-mile warranty.

Cost to Rebuild a 4R100

Pricing depends on the damage found at teardown, the converter, cooling system needs and any upgrades you choose. We give free estimates and explain each line before you approve. Financing is available. For a broader look at diesel work, see our diesel transmission repair page.

Tips for 4R100 Owners

Change the fluid and filter on a severe-service schedule if you tow, add an auxiliary cooler if the truck does not have one, and pay attention to any change in how it shifts. Our article on how Arizona heat affects your transmission explains why the desert is so hard on older units.

4R100 Transmission FAQ

Is the 4R100 a good transmission for a 7.3L diesel?

It is a durable unit that suits the 7.3L well when it is maintained and kept cool. Most failures we see are tied to heat, age and heavy towing.

Can a 4R100 be rebuilt for more power?

Yes. Upgraded clutches, valve body changes and a stronger converter can help a 4R100 hold up to added power and towing.

What does it mean if my truck will not go into overdrive?

It could be a solenoid, wiring, a sensor or a worn overdrive section. A scan and road test are needed to know which.