Torque Tube U-Joint Ball Housing Adjustment
Powerglide, Hydra-matic and manual shift trans. Ball Housing Adjustment are the same.
What it sounds like to me is the Wrench who does the work for you.
Might be not using the correct number of shims.
If the Ball Collar
is to close to U-Joint Ball Housing it will tear the cork seal.
That's what the paper shims are for, to adjust how close or far the Ball Collar is from the U-Joint Ball Housing.
Note: The Powerglide and 1/2 ton Hydra-matic transmissions are the only torque tube drivelines
that use a separate stamp out piece metal to be used as the "Ball Seat".
The manual shift transmission ball seat is cast into it's tail housing.