water in lower unit after one use

[Jmac870]

Just replaced the gear oil in my 76 johnson 9.9 and after one use the oil is cream colored. IM guessing this is the seal around the shaft leaking? I pulled several chunks of black rubber through the 6 exhaust holes on either side above cav plate, is this my shredded seal?

 

[phillnjack2]

Re: water in lower unit after one use

sounds like it is.
this could of been done by dry running or simple fishing line caught around the shaft.
I would drain the gearbox and put a small drop of petrol in there and swish it around a fair bit.
then drain it again and then put an egg cup full of oil in and swish it around again .
open the drain and let everything out and leave it draining over night.
this will get out all traces of water, but obviously will not repair the seal if its damaged.
My test is just to make sure no water is in the gearbox, but it got in somehow sometime, so to be 100% sure I would
take the leg off and put new seals in both on the drive shaft and the propeller shaft, that is the only real way to make
sure its not going to happen again.
do it now before it gets more water and more corrosion gets in and ruins a perfectly good gearbox.

phill

 

[Jmac870]

Re: water in lower unit after one use

Thanks Phil I will order new seals and in the meantime drain the unit out as you suggested

 

[racerone]

Re: water in lower unit after one use

Lower units are pressure tested to find leaks.----Do not forget the o-ring on the shift rod !----The rubber bits you found may well be from the upper motor mounts.

 

[boobie]

Re: water in lower unit after one use

Before you take it apart, have it pressure and vacuumed tested. Takes the guess work out of where it's leaking.

 

[71Windsor]

Re: water in lower unit after one use

Did you drain the gear oil completely or just force the new in until the oil came out the top hole clean?
Also when you took the bolts out to drain and fill it did you replace the washers on them?

 

[Jmac870]

Re: water in lower unit after one use

I let it drain overnight and it was not dripping the next day when i filled it back up, where could a guy get his lower unit pressure tested?

 

[71Windsor]

Re: water in lower unit after one use

You can actually test it your self. The tools are available at your auto part store. But first I would recommend getting an OMC shop manual for your engine so you will have the information at your hands for how much pressure to expect and the procedures for testing

 

[Jmac870]

Re: water in lower unit after one use

And no I did not replace the washers on the bolts

 

[Grub54891]

Re: water in lower unit after one use

15 lbs of pressure is the normal test.Squirt soapy water around the seals when you pressure up,the leaks will show up.
And if ya didn't replace the washers,it can leak from them.

 

[boobie]

Re: water in lower unit after one use

Most boat dealers with a shop have testers to do it.

 

[71Windsor]

Re: water in lower unit after one use

You should always replace the washers on the fill and vent screws there are not re usable. Those who do with out leaks get pretty lucky. 20 cents is hard to stomach when you trash your lower unit. After you changes the oil in your lower unit you said you went out on the water. How long would you say the engine was submerged before you took it home to find water was in there. Also it doesn't take much water at all to contaminate the oil turning it into chocolate milk.