water in lower unit

[gjankowski]

everytime I use the boat and check the lower unit<br />after the oil comes out milky, I've changed both<br />vent and drain plugs and both gaskets and it still does this, the motor is a 93 merc 40hp 4 cyl<br />oil inj. it looks new and runs great and cannot see any visual signs of a bad seal-HELP!

 

[graddy]

Re: water in lower unit

You need to take the L/U off drain the gear lube and presure test it up to 5psi, then 10 psi.. Spray soapy water around all the seals and air will bubble out the failed seal.

 

[zzzzz]

Re: water in lower unit

GJ-the most common failure spot is the oil seals at the prop...fishing line gets caught up,wraps around the prop shaft and cuts into the seals

 

[BillP]

Re: water in lower unit

You can't look at a seal and tell if it's a "little" bad so prudence is to just replace it. <br /><br />H20 may be coming in at the seal below the water pump. This is positioned horizontally and can hold abrasives that promote wear. Water also sits here against the drive shaft and can leave deposits that eventually pit the shaft where the seal rides...this causes major seal wear and does it rapidly.