Logo

Pre-1988 Mariner Outboard Lower Unit Gearcase Seal

Lower Unit Gearcase Seal

Sealing the gear oil inside the gearcase, and keeping water from intruding into the gearcase are the two aims of all the shaft seals, O-rings, spaghetti seals and gaskets in a lower unit. When you check your gear oil as a part of regular inspection, if you find the oil to be milky, it means water has been introduced somewhere. A seal kit and fresh gear oil will put you back in the safe zone.

Need other parts? If you need parts not listed in the application guide, please see:

Model Serial Code Serial No. Range Lower Unit Seal Kit
2A 646 Obsolete
2B (M) 6A1 000101 - 008800 Obsolete
2B (M) 6A1 008801 - 115871 27-96338M
2B (M) 6A1 131232 & up Obsolete
3.5 642 Obsolete
4A (M) 6E0 001011 & up 27-96324M
4A (ML) 6E0 300101 & up 27-96324M
5A 661 Obsolete
5C (M) 6E3 102151 & up 27-96324M
5C (ML) 6E3 400101 & up 27-96324M
6C (M) 6H8 000317 & up Obsolete
6C (ML) 6H8 300171 & up Obsolete
6D (M) 6H6 001302 & up Obsolete
6D (ML) 6H6 300406 & up Obsolete
8A 655 Obsolete
8B (M) 677 000101 & up 27-84172M
8B (ML) 677 300101 & up 27-84172M
8C (M) 6G1 007990 & up Obsolete
8C (ML) 6G1 305951 & up Obsolete
8C (MUL) 6G1 700388 & up Obsolete
9.9C (M) 682 000551 - 023105 Obsolete
9.9C (ML) 682 300826 - 328485 Obsolete
9.9C (E) 682 250101 - 250800 Obsolete
9.9C (EL) 682 550141 - 551715 Obsolete
9.9C (M) 682 023106 & up Obsolete
9.9C (ML) 682 328486 & up Obsolete
9.9C (E) 682 250801 & up Obsolete
9.9C (EL) 682 551716 & up Obsolete
15A 651 Obsolete
15C (M) 684 000101 - 013275 Obsolete
15C (ML) 684 300101 - 312685 Obsolete
15C (E) 684 250101 - 250805 Obsolete
15C (EL) 684 550101 - 551255 Obsolete
15C (M) 684 013276 & up Obsolete
15C (ML) 684 312686 & up Obsolete
15C (E) 684 250806 & up Obsolete
15C (EL) 684 551256 & up Obsolete
20A 653 Obsolete
20C (M) 6A9 000101 - 010111 27-41899M
20C (ML) 6A9 300101 - 306542 27-41899M
20C (E) 6A9 250101 - 250819 27-41899M
20C (EL) 6A9 550101 - 550693 27-41899M
20C (M) 6A9 010112 & up
20C (ML) 6A9 306543 & up
20C (E) 6A9 250820 & up
20C (EL) 6A9 550694 & up
25A 648 Obsolete
25C (M) 695 000101 - 023895 27-41899M
25C (ML) 695 300101 - 318173 27-41899M
25C (E) 695 250101 - 253861 27-41899M
25C (EL) 695 550101 - 555959 27-41899M
25C (M) 695 023896 & up
25C (ML) 695 318174 & up
25C (E) 695 253862 & up
25C (EL) 695 555960 & up
28 664 Obsolete
30A (M) 689 000366 - 022058 27-41899M
30A (ML) 689 301911 - 3213767 27-41899M
30A (E) 689 100251 - 105324 27-41899M
30A (EL) 689 401216 - 411946 27-41899M
30A (M) 689 022059 & up
30A (ML) 689 321377 & up
30A (E) 689 105325 & up
30A (EL) 689 411947 & up
40A 676 Obsolete
40B (M) 676 B000106 & up 27-94533M
40B (ML) 676 B300101 & up 27-94533M
40B (E) 676 B100461 & up 27-94533M
40B (EL) 676 B400420 & up 27-94533M
40C (M) 6E9 000106 & up 27-94533M
40C (ML) 6E9 300126 & up 27-94533M
40C (E) 6E9 100101 & up 27-94533M
40C (EL) 6E9 400231 & up 27-94533M
48 670 Obsolete
W-48 (M) 670 002161 & up Obsolete
W-48 (ML) 670 311996 & up Obsolete
55 (M) 663 Below - 02730 Obsolete
55 (ML) 663 Below - 34925 Obsolete
55 (M) 663 02731 & up Obsolete
55 (ML) 663 34926 & up Obsolete
55 (E) 663 004041 & up Obsolete
55 (EL) 663 315379 & up Obsolete
W55 (ML) 663 578278 & up Obsolete
60 (E) 675 00101 - 001170 Obsolete
60 (EL) 675 30101 - 304180 Obsolete
60 (E) 675 001171 & up Obsolete
60 (EL) 675 304181 & up Obsolete
60 (E) 6F0 000101 & up Obsolete
60 (EL) 6F0 300311 & up Obsolete