T90 Transmission Parts for Willys CJ3B

Why the T90 Transmission in the Willys CJ3B Needs Attention After Years of Use.

The Borg-Warner T90 3-speed transmission in the Willys CJ3B is a rugged but now decades-old unit, and wear here is entirely normal. Input and output shaft bearings wear down continuously under load and speed, developing play or running noise. Seals harden over the years, lose their elasticity, and start leaking oil. The shift mechanism itself – shift rail balls, springs, and the shift knob – suffers from constant use and can wear loose or bind up. The main shaft lock nut also loosens over time from vibration and needs replacing along with its washer to maintain proper bearing preload. Anyone rebuilding a T90 or fixing an oil leak should check all wear parts together rather than replacing items individually.

• Bearings & Spacers: The output shaft bearing and input shaft bearing (note: the included snap ring doesn't fit the T90, part 640782 is needed for that) along with the main shaft spacer.
• Seals & Repair Kits: The T90 gasket kit for smaller repairs and the complete overhaul kit with bearings, seals and hardware for a full rebuild.
• Shift Mechanism: The matching shift knob and the shift rail ball.
• Main Shaft Hardware: The main shaft lock nut with its matching washer.

American Manufacturing Quality from a Single Source.

All parts for the T90 transmission come from Crown Automotive – an established American manufacturer whose reproduction parts are built to OEM specifications with precise fitment. From bearings to gasket kits to the complete shift mechanism, you benefit from consistent American engineering and fitment throughout.

Your Partner for the T90 Rebuild.

Whether you need a single wear part or a complete transmission overhaul, we're happy to advise you on installation order, torque specs, and possible deviations with supplied hardware like the snap ring on the input shaft bearing. Most items ship from stock within 1-2 days.