What Transmission Does A 7.3 Power Stroke Have?

Introduced in 1994, the 7.3L Power Stroke engine was offered as the diesel engine of choice in Ford's heavy-duty range of pickups. The introduction of the Power Stroke V8 saw Ford's diesel-powered trucks benefit from direct injection and turbocharging technology for the first time, catapulting them leaps and bounds ahead of both competitors and preceding models. Keen to impress, Ford ensured the Power Stroke diesel engine offered drivers plenty of grunt, with peak power and torque arriving near the end of the engine's production run, at 275 horsepower and 525 lb-ft.

The most powerful Power Stroke configurations were reserved for trucks equipped with manual transmissions, while automatic Super Duty trucks sported slightly lower outputs in order to not stress the transmission. Before being replaced in 2003 by the 6.0L Power Stroke, a variety of hard-wearing automatic and manual transmissions were available throughout the 7.3 Power Stroke's lifetime. Here's a closer look at the transmissions which were mated to the 7.3L Power Stroke V8 during its nine-year production run.

Predominantly, Ford's heavyweight F-Series models during this era were equipped with automatic transmissions. Throughout the 7.3L Power Stroke's nine-year production run, the only automatic transmission of choice was a four-speed, although two different iterations were sold.

Initially, automatic Power Stroke trucks would be equipped with the E40D — an existing transmission which powered the previous generation of F-Series models. This four-speed auto arrived in 1989, preceding the 7.3L turbo-diesel engine. As the power and torque outputs of the F-Series range grew, Ford thought it wise to revisit the E40D, and as a result, it was replaced by the revised 4R100 transmission in 1998.

While similar in many ways, the 4R100 transmission boasted key upgrades in comparison to the E40D, notably a pulse-width modulated torque converter clutch solenoid, output speed sensor, and redesigned oil pump. These additions were introduced with the aim of improving upon the four-speed auto's efficiency and reliability. While the 4R100 is certainly far from a bulletproof unit, it stills proves a popular and capable choice with Power Stroke owners today.

While automatic transmissions were certainly the more popular choice, some owners preferred the control and engagement of a manual transmission. Throughout the 1994-2003 period in which the 7.3L Power Stroke was in production, two manual transmissions were offered by Ford in these heavy-duty trucks.

Initially, a five-speed ZF5 transmission was offered. Before long, this was replaced with a ZF6 transmission, which boasted six forward gears, a low gear for crawling, and an overdrive gear, ideal for highway cruising, as well as the reverse gear.

Generally speaking, the Power Stroke's manual transmissions are considered to be just as reliable a choice for the diesel-powered F-Series trucks of this era as the revised 4R100 automatic. However, automatic transmissions can prove to be sluggish, especially as they age, whereas the driver has complete control over both the rpm and when gear changes happen with a manual. This is why some will prefer the latter, especially when towing, as slow changes can drastically thwart progress when pulling off or climbing uphill.

Modifications such as larger wheels and tires, more power, and increased torque will put excess stress through a transmission, and therefore shorten the unit's service life. F-Series trucks are highly customizable, and so many owners do choose to carry out such mods to their trucks, which means stock transmissions quickly highlight themselves as weak points.

Upgrades are common, especially rebuilt and strengthened 4R100 transmissions, although freshly refinished units can easily cost multiple thousands of dollars, up to $6,000. Billet torque converters, a new valve body, and larger oil coolers are common upgrades for the popular 4R100 transmission, and usually factored into most high-quality rebuilds. 

Although pricey, DIY kits and rebuilt transmissions continue to appeal to enthusiasts, and to those who still continue to push the capabilities of these older 7.3L Power Stroke diesel trucks. The financial outlay in exchange for improved reliability and peace of mind is oftentimes easily justified.