A hydrodynamic shaft seal assembly (10.110, 210, 510) comprising: a carrier (16, 116, 216); said carrier (16, 116, 216) being formed of a rigid, metallic material; said carrier (16, 116, 216) having a generally annular configuration; said carrier (16, 116, 216) including an annular outer wall (18, 518); said carrier (16, 116, 216) including an annular flange (24, 124, 224, 524) extending radially inwardly relative to said outer wall (18, 518); said carrier (16, 116, 216) including a rubber casing (26, 126, 228, 526) enveloping at least a portion of said outer wall (18, 518) and said annular flange (24, 124, 224, 524); at least one excluder member extending radially inwardly from said carrier; said excluder member having at least one cantilevered rubber lip (30, 32; 132, 232, 532); said excluder member directly contacting said annular flange (24, 124, 224, 524) of said carrier (16, 116, 216); an annular PTFE seal member (34, 134, 234, 534) mounted on said carrier (16, 116, 216) and extending radially inwardly therefrom in a free-state condition; said seal member (34, 134, 234, 534) having an outer section (36, 136, 236, 536) adjacent said carrier (16, 116, 216), an inner section (38, 138, 238, 538), and a mid portion (40, 140, 240, 540) disposed between said inner (38, 138, 238, 538) and outer (36, 136, 236, 536) sections; said outer section (36, 136, 236, 536) in direct bonded engagement to said rubber casing (26, 126, 226, 526) of said carrier (16, 116, 216); said inner section (38, 138, 238, 538) being flexible for establishing a dynamic sealing surface with a rotating shaft in surface-to-surface contact therewith; said sealing surface having at least one cut-in spiral hydrodynamic groove (42, 142, 242, 542) terminating in said inner section (38, 138, 238, 538) adjacent said mid portion (40, 140, 240, 540) of said PTFE seal member (34, 134, 234, 534); and characterized by, said PTFE seal member (34, 134, 234, 534, 544) including at least one annular undulation (44, 144, 244, 544) formed in said mid portion (40, 140, 240, 540) thereof; said undulation (44, 144, 244, 544) having complimentary concave and convex distortions; said mid portion (40, 140, 240, 540) of said sealing member (34, 134, 234, 534) having a thickness less than the thickness of said inner (38,138, 238, 538) and outer sections (36, 136, 236, 536), wherein said thickness of said mid portion (40, 140, 240, 540) is thinned in a machining operation and said at least one undulation (44, 144, 244, 544) is formed in a subsequent coining operation. a carrier (16, 116, 216); said carrier (16, 116, 216) being formed of a rigid, metallic material; said carrier (16, 116, 216) having a generally annular configuration; said carrier (16, 116, 216) including an annular outer wall (18, 518); said carrier (16, 116, 216) including an annular flange (24, 124, 224, 524) extending radially inwardly relative to said outer wall (18, 518); said carrier (16, 116, 216) including a rubber casing (26, 126, 228, 526) enveloping at least a portion of said outer wall (18, 518) and said annular flange (24, 124, 224, 524); at least one excluder member extending radially inwardly from said carrier; said excluder member having at least one cantilevered rubber lip (30, 32; 132, 232, 532); said excluder member directly contacting said annular flange (24, 124, 224, 524) of said carrier (16, 116, 216); an annular PTFE seal member (34, 134, 234, 534) mounted on said carrier (16, 116, 216) and extending radially inwardly therefrom in a free-state condition; said seal member (34, 134, 234, 534) having an outer section (36, 136, 236, 536) adjacent said carrier (16, 116, 216), an inner section (38, 138, 238, 538), and a mid portion (40, 140, 240, 540) disposed between said inner (38, 138, 238, 538) and outer (36, 136, 236, 536) sections; said outer section (36, 136, 236, 536) in direct bonded engagement to said rubber casing (26, 126, 226, 526) of said carrier (16, 116, 216); said inner section (38, 138, 238, 538) being flexible for establishing a dynamic sealing surface with a rotating shaft in surface-to-surface contact therewith; said sealing surface having at least one cut-in spiral hydrodynamic groove (42, 142, 242, 542) terminating in said inner section (38, 138, 238, 538) adjacent said mid portion (40, 140, 240, 540) of said PTFE seal member (34, 134, 234, 534); and characterized by, said PTFE seal member (34, 134, 234, 534, 544) including at least one annular undulation (44, 144, 244, 544) formed in said mid portion (40, 140, 240, 540) thereof; said undulation (44, 144, 244, 544) having complimentary concave and convex distortions; said mid portion (40, 140, 240, 540) of said sealing member (34, 134, 234, 534) having a thickness less than the thickness of said inner (38,138, 238, 538) and outer sections (36, 136, 236, 536), wherein said thickness of said mid portion (40, 140, 240, 540) is thinned in a machining operation and said at least one undulation (44, 144, 244, 544) is formed in a subsequent coining operation.