What kind of transmission came in a 1989 Ford Mustang 2.3L 4-cylinder. manual?

Answer 1

It is a Borg-Warner (Now Tremec) T-5. It is not the same as the T-5 behind the 5.0L V-8. The end of the input shaft that goes in the pilot bushing of the crankshaft is much smaller. The first gear ratio is 3.35:1. This was the same for the V-8 trans until '92 when Ford installed the "World Class" version of the T-5 which had a higher 2.95:1 first gear ratio and a higher torque capacity than the standard T-5. ( 330 ft.-lbs. versus 300 ft.-lbs.) It should be noted that a stock-as-a-rock 1987 to 1992 5.0L Mustang engine produced 300 ft.-lbs of torque which was maxing out the capability of the standard T-5. With the myriad of easily bolted on performance parts for these cars, the "World Class" model can easily have its torque capacity exceeded. If you race the cars or just try to shift like an Andretti, these will NOT hold up for long. Get a Tremec TR3550 or the Tremec TKO. They require a different bellhousing, which happens to be the '79 to '83 mustang FOUR speed manual bellhousing. The TKO also requires a different driveshaft yoke. (31 spline, stock is 28) As far as a four cylinder goes, they barely have enough power to break traction ,much less the transmission.