What Is A T18 Transmission?

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One of the hardest working transmissions that Ford ever produced was the T18 which stood the test for over 26 years. What exactly is a T18 Transmission?

The Borg-Warner T18 was manufactured from 1965 to 1991 and used in Ford F-Series, Jeep, and International Harvester trucks. The transmission (along with the T19 cousin) is known for being dependable, long-lasting, and indestructible. The T18 replaced the T98, which Ford had used for years.

The mid-60s was a time of crisis, not just for our country but for automakers like Ford, who were watching their sales continue to slip away. The company knew that if it continued to offer antiquated products to the rising younger generation, it wouldn’t be long before their blue oval was a distant memory in a long line of car companies that had gone extinct. Bold actions were required, not just with the introduction of the Mustang but for the entire line of Ford pickups as well. The desire to recapture the magic of Ford led the company to revise the chassis, add a new twin I-beam suspension, provide new powerplants, and back those new motors with a new T18 transmission. Today, let’s explore the T18 tranny to see why it was such a staple of Ford, Jeep, and International Harvester trucks for nearly 25 years.

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What is the T18 Transmission?

The T18 was a heavy-duty four-speed manual transmission developed by Borg-Warner to replace the T98 that Ford had used since the late forties. The transmission was built on a cast-iron case that measured about a foot long and weighed over 145 lbs. Compared to the T98 (cast iron), the T18 was lighter (by about 20 lbs) and had reinforced bearings and lubrication systems designed to counter the weaker T98 and address some of the complaints Ford had received over the years.

According to F150hub.com, The T18 had fully synchronized 2nd, 3rd, and later fourth gears with a specified lower granny gear ratio of 6.32:1 which provided exceptional low torque that many customers had been clamoring for. BorgWarner offered the T18 as a four-gear manual first in Fords, Jeeps, and IH trucks shortly after. Early versions of Ford T18s were first offered on the F100s and quickly gained traction with the rest of the half-ton, three-quarter, and full-ton trucks.

The gear ratios are listed below.

Make First Gear Second third Fourth Reverse
Ford/Jeep 6.32:1 3.09:1 1.69:1 1.00:1 7.44:1
Jeep/IH 4.02:1 2.41:1 1.41:1 1.00:1 4.73:1

The T18 was a top-loader, which means that the gears and guts of the transmission could be worked on by removing the cast iron top cover plate. (The configuration wasn’t new since it borrowed it from the T98 transmission). Borg-Warner used the T98 covers for many early T18 transmissions, which often confused technicians and truck owners alike. (The only way to know the exact transmission you were working on was to rip off the top cover to see). Ford offered the T18 in 2WD and 4WD applications with a six-bolt pattern often labeled the “butterfly” due to how the holes were shaped on the casing.

Early versions of the T18 had a unique shift pattern with the reverse setting located over and up near the third gear. Then in 1978, when the reverse shifter fork was modified, moved to the top rather than on the side as it had been, and all three forks started to be fashioned with aluminum, the reverse gear moved over and down by the fourth gear setting.

How To Identify A T18 Transmission

The Ford transmissions will have a casting stamp on the driver’s side of the cast iron case, which reads T18 - 1E (earlier models) and 13-01 (for later versions).  Jeep T18As are found by casting numbers from #13-01-192, 193, 209, or 210.

When Did The T18 Begin In Jeep Vehicles?

Within a year, the Borg-Warner T18 was finding its way into Jeep products, where many Americans became acquainted with the durable transmission. The extra low granny gear appealed to off-roaders, who loved the lower crawling speeds they could achieve as they tackled terrain. Suddenly, Jeeps could climb hills and rocky roads without worrying about tearing out components of the powertrain.

Over the years, Jeep introduced twelve different models of the T18, varying the input shaft and gear ratios. Early versions of the Jeep T18 had longer input shafts and were different from the Ford T18 in terms of first gear granny ratios (Ford - 6.32:1 vs Jeep 4.02:1. Later, 1977 - 1979 CJ T18s were produced with an output that matched the earlier Ford with a 6.32:1 lower first gear).

How Many Versions of the T18 Were Made?

There are many different variations of the T18 that were produced. In 1967, the T18B was designed for use in heavy-duty diesel trucks, and although it is rare, it has a much lower gear ratio (similar to the Jeep T18A) in first through third gears. The transmission was a taller, more hefty version of the previous BW transmission.

The T19 transmission was a version that borrowed much of the components of the BW T18. While it featured a taller profile, the T19 was used in larger construction trucks (gas and diesel) for several years and in International Harvester Scouts in the late 70s. The T19 was still offered in Ford pickup trucks as late as 1985.

Is The T18 A Good Transmission?

The T18 is one of the most reliable transmissions ever produced and is a favorite among restorers everywhere.

The Transmission usually backed up large displacement V8s, which many truck owners were demanding at the time. Capable of handling the increased horsepower and torque that many of these engines produced, the lower gears provided increased towing and performance capabilities. (The BW transmission was often paired with the 460 cid V8 which produced 385 lb/ft of torque).

While Ford trucks had to weather two oil embargos and some slumping sales in the late 60-70s, there is no question that this transmission was an integral part of making Ford trucks what they are today.

Why Do Restorers Like The T18?

Parts and products related to the T18 are plentiful and inexpensive. Due to the sheer number of these transmissions, plenty of aftermarket parts are available. As a rule, the T18 is one of the most straightforward, simplest transmissions and are considered the best conversion unit due to universality. Many components for Jeep vehicles (transmissions) are no longer made and are almost impossible to find.

The transmission is adaptable to some GM and AMC engines, which gives it a wider application than many factory stock transmissions that might be impossible to find replacement parts for. Many restorers are supplanting the Ford T18s into their Jeep restoration projects due to the ease of installation and the scarcity of parts for older Jeep models. While many different companies make aftermarket parts, an example of a rebuild kit is this Transparts Warehouse kit sold on Amazon.