The sealing rings are synthetic resin with chamfered ends. Check the condition of the sealing rings, and replace them only if they are worn, distorted, or damaged.
For a better fit, squeeze sealing rings together slightly before installing them.

Apply ATF to the new sealing rings, then install them on the secondary shaft.

After installing the sealing rings, verify the following:
The rings are fully seated in the groove.
The rings are not twisted.
The chamfered ends of the rings are properly joined.
Mainshaft Bearing and Oil Seal Replacement (M/T)
Special Tools Required
Driver Handle, 15 x 135L 07749-0010000
Bearing Driver Attachment, 37 x 40 mm 07746-0010200
Bearing Driver Attachment, 52 x 55 mm 07746-0010400
Adjustable Bearing Puller, ...
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A/T System Description - Hydraulic Controls (A/T)
Hydraulic ControlsThe valve body includes the main valve body,
the regulator valve body, and the servo body. The ATF pump is driven by
splines on the end of the torque converter which is atta ...