1998 BRAVO 1 twin 454 300 hp Searay, not mine trying to help somebody.
Upper bearing (the set on the yoke shaft) went bad, he replaced and within 1 hr. the new bearing seized and bound motor to halt. Work was done by a shop. Oil full and looked OK.
What could have gone wrong? Could this be a bad upper case?
Vague but just trying to help another out as to what to look at and possible causes.
Thanks in advance.

Anybody?

Sounds like the pre load wasn't set right.

That was my first thought also, but, what caused the original set to fail?
Could there be something wrong with the upper case?

Did he go back to the repair shop that just installed the bearing for their opinion, ,possibly the pre load on the pinion nut was way too tight.,that will destroy the bearing

A boat shop in Florida take responsibility, really?
All kidding aside he wants to get some ideas so he can talk with some basic knowledge as to possible causes. He is thinking something wrong with upper case. I am not sure if this is his idea or something the shop suggested.

GLENAMY 242SS A boat shop in Florida take responsibility, really?

Wow I didn't know the repair shops in Fla. were that way.
The case may be damaged now if it bound the engine to a halt.

What did the gear lube look like when he drained the outdrive the after the first failure ? Was there a ton of scrap metal on the magnetic drain plug ?
Maybe there are issues beyond the pinion bearing causing the problem. ?
Post what your finding are when you solve the Mystery !
Big Boy Toys

What area of Florida?

I think from St. Lucie area, he has not called me back so no info avail.