Scag deck gear box question

[PTmowerMech]

Scag Turf Tiger
M#STT52A
S# 6670107

Engine runs fine. Everything on the deck, spindles and idlers have good quiet smooth bearings. With the exception of the gear box. I can't turn it at all. With the belt off, I engage the PTO, I can't tell if anything is turning or not.

Tomorrow, there'll be people here that'll give me a 2nd set of eyes to see what's going on with the PTO engaged. But for now, just looking for some insight on this problem.

 

[PTmowerMech]

Got the gear box out this morning. And it's locked up. I tapped the pulley a little one way, and no movement. Tapped it the other way and it barely moved. So I kept tapping it til it free'd up. Gonna still replace it though.

 

[Dwellonroof]

please post pictures of the gear box and what the problem is.