gear oil coming from water inlet

[refg3880]

just changed the lower unit oil (alpha one) and ran the boat to get the motor oil hot to change, changed the motor oil went to bed, woke up went to work came home and saw brand new clean green merc gear oil coming from the water inlet. what did i do wrong? i pumped the oil in from the bottom til it came out the vent and replaced the plugs. it never did this before. did i hurt it somehow?

i see that when i search it people say driveshaft seal, but which one is that. (see link below page 10)


boatfix.com/merc/servmanl/6/6b3r3.pdf




thanks my first i/o trying to learn

bob

 

[ziggy]

Re: gear oil coming from water inlet

what did i do wrong?

don't sound like ya did anything wrong. only thing that could happen would be ya either forgot to replace the plug seals (which are not orings, their special mercruiser seals) or maybe ya stacked two together. this happens when the seal stays with the drive when ya remove the plug and ya don't catch on to go get it + replace it with new.

other than that. yer probably gonna need to pressure test your drive to help locate the seal failure.

the attachment is where the seals are at best i know (pic is mc-1). + the drain plug seals which are not shown.

 

[paultjohnson]

Re: gear oil coming from water inlet

I just went thru that... It ended up being the 2 oil seals in the bottom of the impeller assembly.. I bought a new impeller base, it has the 2 seals already installed Was under $30. To troubleshoot, I seperated the upper from the lower, blocked the little hole where the quad ring goes. Put a pressure checker on the lower. Put in 15 psi, then started spraying soapy water on the innards. Had bubbles coming up around the drive shaft where it comes out of the plastic impeller housing... A relatively easy repair... Just a thought.

 

[refg3880]

Re: gear oil coming from water inlet

so it turns out that my father was showing the boat to the neighbor and ran the boat for 30-40 secs with no water hooked to it. did he burn up my impeller? and now its leaking?
whats this gonna cost me?

 

[ziggy]

Re: gear oil coming from water inlet

did he burn up my impeller?

that didn't do it any good... check this out.

whats this gonna cost me?

the time to go inspect your impeller + even if it's not bad ya might as well R&R it since your there looking at it... so about $50 for an impeller only. if damage has already been done, blades missing, you will have some more work ahead of you.

since ya got a lub leak anyways, might as well take the drive off and pressure test it, see if ya can find the leak, if not, separate the halves to go for the impeller. then pressure test the halves separate to find the lub leak.

 

[refg3880]

Re: gear oil coming from water inlet

but would a burned up impeller cause a oil leak? and i really dont understand how to perform the pressure test.

 

[Bt Doctur]

Re: gear oil coming from water inlet

5 seconds is too much without water, split the units and i`m sure you see the damage.

 

[ziggy]

Re: gear oil coming from water inlet

but would a burned up impeller cause a oil leak?

no, ya smoke impellers because of no water supply to the sea water pump that's located in the lower unit of the drive. also, low water flow can cause them harm too.
as to the pressure test. ya empty the gear lub out of the drive via the drain hole in the lower unit. remove the vent screw in the upper unit of the drive and the lub flows out. then ya look at the link i put ya onto and go about building yourself a pressure tester. several different ones to copy in the link. then ya pump up the drive to 15psi, if ya ever get that far due to the leak. then listen and try to find where the air is escaping from. if you still can't locate the leak, some soapy water misted on will help. if ya still can't find it, separate the halves and plug the gear lub passage on which ever half your working on, the pump it up again, listen for the leak, if ya still can't find it, soapy water...

here's a couple pics of some impellers i've done..

these are all one season impellers, all were run for 5 or 10 sec. w/o water if i remember, and i do. all curled, all have creases on the underside, rubber is degrading.

this one got run on low water flow. i had the start of an overheat in the driveway + it was letting the magic impeller smoke out of my drive.

 

[paultjohnson]

Re: gear oil coming from water inlet

I would say its very possible that toasting the impeller could lead to the lower water pump oil seals failing, those seals are right below the impeller and actually part of the water pump assembly. That lower drive shaft can move side to side quit a bit. It actually moves upward when you put it in gear and put a load on the prop. Ya may wanna just replace the whole water pump/impellar assembly. Maybe not. see what the damage is. Fortunately you will be in the $50 - $75 or so dollar range.
Pressure check. You can buy or make a pressure tester. There are some samples of homemade ones here on the forum... Stickys I believe [ Now ya gotta fig out how to find those]. I made one with a plastic T - fitting, a tire pressure gauge [round one with a dial], a schrader valve from a bicycle tire innertube. The connector from my gear oil pump. And some hose. You hook it up to your drive in the vent or fill holes. If your testing the upper and lower all in one piece, screw it into the top vent, and plug the bottom fill hole with the drain plug. Screw the lube oil fitting into the drive. Take a air pump or air compressor, add air thru the tire valve till ya have 15 psi on the gauge. It should hold over nite if alls good. You are probably gonna have to split the drive and do each half independently. You have to block the little hole on the drive that allows lube to flow from the lower to the upper and vice versa. where the quad ring is on the starboard side. Put 15 lbs on the lower half and see where it leaks, ya might be able to hear it,. Or spray soapy water around everything and look for bubbles.

BTW Ya do pressure checks with the outdrive drained !