1340-20 – Stub Midship Shaft – 20 X 1.310 Splines – Butt Dia 2.435″ – End To Weld 7.500

A failed midship shaft announces itself as vibration that worsens at highway speed and does not disappear after U-joint replacement. The 1340-20 stub midship shaft -- 20 X 1.310 splines, 2.435" butt, 2.560" x 0.065" tube -- provides a precision replacement that restores the dimensional accuracy required for a vibration-free two-piece driveshaft.

Midship Shaft Failure Modes

Stub midship shafts fail for several reasons: center support bearing collapse allows tube deflection; corrosion attacks the tube wall, reducing structural stiffness; and impact damage introduces runout that unbalances the entire driveshaft assembly. The 1340-20 eliminates these issues with a fresh, balanced tube and factory-accurate dimensions.

Part Data

Center Support Bearing Interface

The center support bearing seats on the butt diameter (2.435") of the 1340-20. The bearing must be fully pressed to its seat and the bracket fasteners torqued correctly to hold the midship shaft in the proper driveline angle. An incorrectly shimmed or loose center support bearing transfers vibration into the cab and will damage the bearing itself in short order.

Replacement Steps

• Remove the rear driveshaft section first to gain access to the midship shaft
• Unbolt the center support bearing bracket from the crossmember
• Mark the front yoke orientation before sliding off the output shaft
• Press center support bearing onto 1340-20 butt diameter
• Install in reverse order; shim center bearing for correct driveline angle
• Road test to verify absence of vibration at all speeds

Get the Right Part Fast

Universal Driveshafts stocks the 1340-20 and matching center support bearings. Order both together for a complete midship assembly. Our driveline team can help you verify fitment using your vehicle's driveshaft data plate dimensions.