I have an 82" 40hp thunderbolt. While changing the impeller I broke this part of the shift shaft while reinstalling g the lower unit. Seems I didn't line shift shaft properly before tightening. I see the part number "75104A8" for the shaft assembly but not this part separately. What is the name of this part of the shift shaft and can it be bought without the shaft. Any help would be appreciated so I don't keep going bonkers looming for it.