A clutch pack in an automatic transmission is powered by a piston. The seal you refer to is the seal on that piston. I do not intend to start a debate, but the fit on those seals is real close and they have a "lip" which if folded back during insertion can break off causing a leak. To avoid this the manufacturer makes a set of "lip seals protectors" to use during assembly. This is true of all transmissions. I own several sets for the A4ld / 5R55 and 4R70W and loan them out. I am often told that it is overkill to use seal protectors and a careful assembler does not need them. With this thread I rest my case. I am as careful an assembler as I know. I use them. I loan them. Those who choose not to use them can proclaim me to be a "little old lady"... I just know what I build. They can build what they want.