3103-10 – Transmission Yokes – 1310 Series – 10 x 1.375 Splines – 2.125″ Hub Dia

The 3103-10 is the shortest of the 1310-series marine jet drive yokes at 2.750" center-to-end. The compact dimension suits jet pump configurations where the pump coupling face sits close to the engine output, leaving minimal clearance for a longer yoke without fouling the hull structure or tunnel frame. The 1.125" counterbore is the largest in the jet drive series (versus 0.875" on the 3103-12 and 1.000" on the 3103-11), indicating a third pump coupling pilot standard.

• 10-spline x 1.375" PD -- standard jet pump input specification
• 2.125" hub OD -- standard for jet drive coupling bore; common across all three variants
• 1.125" counterbore -- largest pilot bore in the series; verify against your pump coupling pilot OD
• 2.750" C-to-end -- shortest in series; measure clearance between pump face and engine output before ordering
• Pair with a serviceable 1310-series U-joint at 1.062" cap diameter; inspect annually in marine service

Tip: when removing a jet drive yoke that has been in saltwater service for multiple seasons, apply penetrating oil to the spline interface 24 hours before removal. Corrosion-bonded splines can seize so severely that standard yoke pullers will fail; heat from a propane torch is sometimes required, but must be applied carefully to avoid distorting the pump coupling housing.