Mercruiser Alpha One, R and MR Serial Numbers 6225577 THRU 0D469858
Upper Steering Shafts
The Upper Steering Shaft connects the steering to the Gimbal Ring.
Early Upper Steering Shafts used a fine spline through the Gimbal Ring and the Steering Lever.
The fine splined proved to be inadequate when worn and was eventually changed to a square shaft.
The earliest shafts had splined gimbal rings and splined steering levers.
Later units used square gimbal rings with splined steering levers.
When replacing an older pre-Alpha splined gimbal ring you will be forced to convert to a square upper shaft.
The Gimbal Ring Kit will include a Square/Splined upper steering shaft to fit the new gimbal ring to the old steering lever.
You can no longer purchase the spline-on-spline upper steering shafts nor should you want to.
You can no longer buy splined steering levers.
You can no longer buy splined gimbal rings.
All replacement components will feature the newer square-holed design.
Upper Steering Shaft (square-square) 98230A1 $407.00
Fits all MR, Alpha One, Alpha ONE Gen II and Bravo drives (not SeaCore).
Lower Steering Swivel Pin
There are two types of lower steering swivel pins.
Early pre-Alpha and Alpha One's used a steel pin with a needle bearing pressed into the gimbal ring.
Later models (Alpha One, Alpha Gen II and Bravo) used am aluminum lower swivel pin with a nylon bushing pressed into the gimbal ring.
The lower swivel pin is held in place with a cotter pin on all models.
Steel Lower Swivel Pin 17-45212 $87.67
Aluminum Lower Swivel Pin 17-99353 changes to 8M0073409 $58.00