Mercury Mariner Outboards: Gearcase Rebuild & Repair Help

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Mercury Mariner Forum Topic: Gearcase Seals

Replies Thread
4 95 99 has water in lower unit how to repair
13 Water in Lower Unit 1991 90 hp
13 Flushing lower unit gearcase
4 New prop shaft seal still leaks.
10 Water in lower unit 1996 125 hp
2 Question about changing oil in lower unit
1 Type of lower unit oil? 1981 50 hp
4 Water in lower unit
1 TIP ( water in lower unit lube)
1 1984 9.9 oil seal under water pump
1 Gear housing disassembling help
9 Milky lower unit oil
3 Water in lower unit oil - 92 Mariner Magnum 40
2 Lower unit drain plug gaskets
2 Oil seal installlation 4.5
4 Water in lower unit. Is this a total rebuild?
17 Water in lower unit
2 Gearcase oil
3 2000 merc 50hp lower unit drain plug help
8 90 hp,2 cyl merc has water in lower unit oil and "slips" ingear under heavy load/speed
2 50 Hp Merc Outbard...Lower Gear Case Oil Capacity
1 Mariner 60 3 cylinder 1996 or 1997 or 1998 year (serial 0G224114) lower unit oil
3 I need lower unit seal for 1964 mercury 110 9.8
9 Water in lower unit., weep hole leaking.
3 Lower unit oil leak
7 Mercury 500 lower unit leak??
4 1980 Mariner 4 a hp gear housing plug question.
2 1972 20hp Mercury Outboard Lower Unit Gear Housing
3 1993 135 Merc. with water in Lower Unit
6 Oil seal help
4 No oil in lower unit of 9.9 Mercury
1 Mercury Prop Shaft Seal
2 Fuel and Lower Unit Oil ?
9 Lower Unit Leak
1 25 hp 1986 upper crankshaft bearing and oil seal
2 1992 6 hp mercury gearcase seal replacement ?
1 1992 mariner 25 hp lower oil seal
6 Lower Unit Oil leak (question on seal kit) - 1976 Mercury 7.5 HP (SN/4400192)
4 Mercury thunderbolt 500 output shaft oil seal change-help!
3 1994 Mercury 90HP Lower Unit Leak

Lower Unit Gearcase Seal Kit for Mercury Mariner Outboard

Mercury Mariner lower unit gearcase seal kitSealing 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.