CJ3A: Drivetrain - The JeepsterMan

CJ3A: Drivetrain

Unveiling the CJ-3A: Mastering the Drivetrain Dynamics

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Embark on a journey through the mechanical symphony that propels the CJ-3A forward. In this edition, we delve into the intricacies of the clutch, transmission, transfer case, and axles that collectively breathe life into this legendary vehicle.


  • Type: Single dry plate clutch.
  • Disc Diameter: Approximately 9 inches.
  • Spline Count: Typically 10 splines.
  • Pressure Plate: Diaphragm-style, ensuring smooth engagement.
  • Throwout Bearing: Included for seamless disengagement.
  • Clutch Pedal Mechanism: A mechanical ballet, choreographed by a responsive clutch pedal.

Transmission: Borg-Warner T-90:

  • Type: Three-speed manual transmission.
  • Gearing: 3 forward gears and 1 reverse gear.
  • Shift Pattern: H-pattern, a dance of precision.
  • Synchronization: Synchromesh on 2nd and 3rd gears for seamless transitions.
  • Gear Ratios:
    • 1st Gear: 2.78:1 - Launch with power.
    • 2nd Gear: 1.58:1 - Glide through the mid-range.
    • 3rd Gear: 1.00:1 - Cruise with efficiency.
    • Reverse: 3.81:1 - Navigate backward with confidence.
  • Output: Power seamlessly transferred to the transfer case for ultimate distribution.

Transfer Case: Spicer Model 18:

  • Type: Two-speed, gear-driven transfer case.
  • Gearing: High range (1:1), Low range (2.46:1).
  • Shift Mechanism: Floor-mounted shift lever, a leveraged interaction.
  • Output: Power gracefully delivered to both front and rear axles.
  • Operation: Tailor your drive - high range for a direct drive, low range for increased torque, adapting to diverse driving conditions.

Front Axle: Dana 25:

  • Type/Name: Dana 25, the stalwart of the front assembly.
  • Ring & Pinion Ratio: 5.38:1 (Standard), the perfect harmony.
  • Axle Shaft Type: Two-piece, semi-floating, ensuring agility.
  • Operation: Power coursing through, steering with finesse, and providing relentless traction.

Rear Axle: Dana 41:

  • Type/Name: Dana 41, the backbone of the rear.
  • Design: Solid axle, a robust foundation.
  • Axle Shaft Type: Full-floating, enduring the torque.
  • Ring & Pinion Ratio: 5.38:1, synchronizing power and efficiency.
  • Operation: Transmitting torque with unwavering resolve, empowering the wheels.

As we unfold the mechanical symphony of the CJ-3A, stay tuned for Part 6, where we explore the suspension, steering, and braking systems. For authentic parts and expert guidance, trust JeepsterMan to keep your CJ-3A running at its peak performance. Your journey awaits, and the adventure continues!

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