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You have to remember the tranny was designed for approx 100ftlbs of torque in a sub 2500lb car, not a truck weighting a lot more with almost 50 more ftlbs. It is marginal in our application.


I think you're confused about this transmission. The KM/FM145 is a solid transmission. It's all about maintenance. The FM145/46 was the higher end option for the Ford Ranger and was offered behind the V6 engine options. The Toyo Kogo/Mazda Tranny was a hot mess and was typically used on 4cyl engines. The FM145/46 has a decent reputation among Ranger owners when properly maintained. Much like the FM145, the KM145 is a ball bearing transmission. If you do not take care of those ball bearings they will develop flat spots. It is important that you change the fluid every 30-40K miles. A transmission that has roller bearings are less prone to flat spots when neglected but I recommend properly maintaining your transmission no matter what your vehicle.

Like you had mentioned ATF is recommended for these transmissions because they have difficulty shifting when cold. I would recommend Mercon ATF.

Spence
1985 Mitsubishi PU 2.3 Turbo Diesel, 13" lift, Watercooled turbo, 4D56 Head, Atlas II,Fox Coilovers, Elockers,

1983 Mitsubishi PU 2.5 Turbo Diesel 4x4, fully restored

2003 G500, sliders, beadlocks, roofrack, ladder etc.