1253-242

The 1253-242 stub shaft or midship shaft is a critical intermediate driveline component used in multi-piece shaft assemblies. With a 1.875-inch butt diameter and 24 x 0.995 spline engagement, it connects the front and rear shaft sections while carrying the center support bearing journal that holds the midshaft in alignment with the vehicle's chassis tunnel.

Dimensional Specifications

Multi-Piece Driveshaft Architecture

Long-wheelbase trucks and commercial vehicles use two-piece or three-piece driveshafts to avoid the critical whirl speed problem that occurs when a single long shaft is rotated at high RPM. The stub or midship shaft is the intermediate member of this assembly, supported at its midpoint by the center carrier bearing and connected to the rear shaft section at its output end. The bearing journal diameter -- 0.985 inches on the 1253-242 -- must match the carrier bearing's bore for correct fit and concentricity.

Installation and Alignment

• The center support bearing must be shimmed or adjusted so the stub shaft centerline aligns with the front and rear shaft segments -- misalignment of even 1-2mm introduces a permanent operating angle that causes vibration
• Confirm the spline engagement (24 x 0.995) is compatible with the mating nut or coupling specified in the notes: use is with : 1204-241 nut sold sepratly: 858018
• Torque the end nut to specification and verify with a calibrated torque wrench
• After assembly, dynamically balance the complete two-piece assembly on a driveshaft balancer for best NVH results

Specialist Stock at Universal Driveshafts

The 1253-242 midship shaft is a specialized component stocked for direct-replacement applications. Our driveline engineers can cross-reference superseded part numbers and confirm fitment for your specific vehicle and build configuration.