Borg-Warner T150 Transmission

The Borg-Warner T150 transmission was the three-speed transmission found in 1976 to 1979 Jeeps. It is a good transmission when well maintained and in situations where an ultra-low first gear isn't required.

Rated at medium-duty, the T150 is stronger than its compact size may suggest. The T150 is a top loaded, top shifting transmission. The T150 is fully synchronized in the second and third gears. All gears are helically cut except reverse.

The T150 transmission is 9.25" long and features a cast iron top cover that is retained by eight bolts and a main case of cast iron.

The Jeep T150 has a 1-3/8" x 6 spline output shaft for mounting the transfer case input gear. The transmission has a 7-1/2" input shaft (stick-out length) with 1-1/16" x 10 splines and a neoprene front seal and cast iron bearing retainer. The pilot tip is ~17mm.

The T150 features a conventional "H" shift pattern, with reverse being towards the driver and up. Typical casting numbers found on the T150 are 2603983 or 2603347.

T150 Specifications

The T150 is based on the Ford RAN three-speed transmission as found in Ford truck, van and early Bronco applications.

The T150 is frequently retained in CJ Jeeps when married to GM V6 and V8 power. It is regarded as the second strongest of all the Jeep three-speeds, second its predecessor, the Jeep T15.

Of interesting note, the T150 transmission was the subject of a recall in the late 1970's, for its rear seal being installed backwards. This seal should face spring-side towards the front of the transmission - see adjacent image.

For the big-gears crowd, the T150 is sometimes replaced with the Ford T18 and Ford NP435 transmissions, since they share a similar bellhousing bolt pattern and compact installations.

Transfer Case Compatibility

The Jeep T150 was factory-married only to the Jeep Dana Spicer Model 20 transfer case.

It would be theoretically possible to bolt a T150 to a large case / large bore (4") Jeep Dana 18 transfer case, but this transmission uses a uniquely machined transfer case input gear with a seal journal and this transfer case gear does not interchange with any Model 18. An option would be to forego the seal and let the transmission and transfer case share transmission oil. The image, right, shows a Dana 18 and Warn overdrive.

The Jeep Dana 300 transfer case is not compatible with the T150.

Bellhousing Adaptability

GM

Buick V6, Chevrolet Small Block V6 and V8 conversions to the T150 are done with steady frequency and success.

AMC Jeep

As the T150 was married to the Jeep AMC engines, it is OEM compatible with them using the 6-1/2" deep 1976-1986 bellhousing as found behind AMC I6 and V8 engines.

Ford

The T150 has a front bolt pattern is the symmetrical Ford "butterfly" pattern; roughly 8-1/2" wide by 6-5/16" tall. It is sometimes married to Ford V8 power, as discussed here.

Rebuilding the T150

When filling your T150 with gear oil, we recommend that you select a conventional mineral oil or a para-synthetic in lieu of a full synthetic oil. Properly assembled manual gearboxes do not have the thermal strains seen by combustion engines or hypoid gears. Synthetic fluid in these gearboxes, while not harmful, is probably an economic waste.

Hypoid gear oil is sulphurized higher than transmission oil and can be mildly corrosive to the non-ferrous alloys used for synchros, bushings and thrust washers in these transmissions.

An 80W-90, API-GL5 or MT-1 rated fluid is very good. Some claim faster shifts from using a 50W engine oil in their transmission and we do not consider this to be contraindicated unless you operate your vehicle in a very warm environment.

The T150 is simple and enjoyable to rebuild. Many shadetree mechanics do very outstanding rebuilds if they have access to a press, snap ring pliers and bearing pullers. Many choose to do a full rebuild during the adaptation process, and our instruction guides feature all the details, diagrams, pics and tricks required to do professional level work.

Summary

The T150 has a good place in Jeep powertrain history. This was not a transmission that was likely to let a Jeeper down, and showed that Jeep could get a strong gears in a compact case, giving favorable driveshaft angles to CJ's. Also, the affordable nature of engine swaps to the T150 means that many retain it for real usage.