I always hate it when you can't find an obvious problem....
Only comment is be super attentive to the service manual to be sure the hydro stat is reassembled correctly--valve plate position and charge pump orientation.
Might as well replace trunnion and main shaft seals while you are at it. Be careful removing the swash plate, follow the instructions exactly, esp, the part about the shaft pin removal.
As Jonathan said, it should work.
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