Instead of a torque converter the Hydra-Matic uses a torus. You'll have to get the Hydra-Matic experts to tell you how it works. Anyway, the cover to it mates to the crankshaft.

"It's just a phase. He'll grow out of it." Mama, 1964

1956 Chevy 1/2-ton 3100
1953 Chevy 6100 "The Yard dog"
1954 GMC Suburban Now with a new proud owner.