Drive Lube Leak
 

Just got back from 7 days of boating on the Upper Chesapeake. However, through the week of boating I had to add a total of 4 ounces of drive oil. I did notice a couple of times small amount of oil floating on the water when I was anchored, and once the boat was back on the trailer I pulled the boat plug and more oil was present there as well. I have since drained the drive oil and it did NOT contain any water or did it look milky.

Any ideal on where the oil is leaking from?
Should I have the drive pressure tested?

I just found a bad propshaft seal on my boat. I was losing a very small amount of drive oil every time going out and finally found it when I was running the boat in gear on the muffs. Shut it off and went to pull the muffs and noticed some lube on the prop. Pulled the prop and sure enough there was a small amount of oil outside the seal. On my drive there is a seal that keeps the oil in and another that keeps the water out(so I was told)

Sad thing is it's lost a little bit every time since I had the drive rebuilt and the dealer that rebuilt it won't help me at all! Even though I brought it to his attention twice before i found it on my own. :(

I would check the propshaft seals and get it pressure tested.

thanks for the info...

That may or may not explain the very little oil I see in the water but not the oil that's in the bulge.

If you have oil in your bilge that could be a seal where your u-joint is. I have no idea what the name of the seal is. But when it goes you'll get oil in your boot and into the bilge.

If you're loosing gear lube, have gear lube in the bilge and don't have water in the outdrive, its the monitor, hose or conection on the transom. Usually it's where the hose connects to the transom on the fitting. Remove the water intake hose from the transom and you can get to the gear lube fitting. Some are plastic and break easily.

I tried to get to the fitting your talking about put did not have and luck. Looks like I need seven foot arms and three elbows. I'll try again tomorrow night. Maybe I need to drink one or two beers first...sometimes that makes it easier to stand on your head.

Yeah, it's about impossible to get at! I'd get a prssure test on the drive anyway, better safe than sorry. You can lose drive oil from seals and not get water in the drive!

I have compressor, gauges and many fitting that will allow me to pressurize the drive.

What is involved in a pressure test? How much pressure 5-10 psi? For how long? Should I drain all the oil? etc...

After having the drive worked on I had a similar problem, had to add fluid and when anchored there was a smell of gear lube. When we pulled the boat, the idiots forgot to put the O-ring on the upper fill screw. Luckily it did not let any water in.

i had oil in bilge due to leaky drive bottles they have a tendency to crack

The best way to pressure check the system is to buy an extra drive oil reservoir cap. Drill and install a barbed fitting into the cap and slip the hose from a small pressure pump onto the fitting. Now pump up the whole system from inside the boat at the reservoir. About 5 - 7 lbs. will do it and let it sit overnight. The next day you will see where the oil was leaking from. Either inside the boat or on your garage floor!
I would guess that it is leaking into the u-joint bellows and then inside the boat through the vent hole in the transom.
Dennis Moore
Mercruiser Master Tech

on mine the driveshaft yoke was a bit worn and had slight rust spots causing a slight leak

Ditto on the drive lube bottle.

I freaked to see oil in my bildge. My mechanic traced it back to the port bottle.

Good luck.

Jeff

My bottles were cracked as well. It was the easiest oil leak I have ever fixed!

Steve

I did notice fluid from what I believe to be the power trim. See photos. This bolt took five complete turns to tighten and the bolt next to it took one turn.

So it seams that I have two leaks, One drive oil leak inside the boat (not sure where) and one power trim outside the boat. See photo.

Does this seam right?

After look at the some more something does not seam right to me. Why would I have oil on the Mercathode Assembly?

Just for yucks and out of curiousity, is there a checkball and valve on your Bravo? When the drive is pulled from the boat, you have to ensure the ball or checkvalve hasn't fallen out. Passing along what happened to me a few years ago.

In my case, the only time that I let a mechanic service my drives, he didn't notice the ball and valve had fallen to the ground when he pulled the drive. The idiot then put the drive back on the boat, filled it to the venthole from the bottom, and then poured lube into the reservoir bottle. Had he filled the drive and the bottle completely from the bottom the way it should be done, he would have noticed the disconnect. No lube would have made it to the bottle because the mechanism was missing. The drive leaked every so lightly, and some down onto the mercathode.

Any gear lube in my bilge has always been from cracked bottles, very hard to see sometimes. I've been through 3 sets in 13 years, just now moved over to the new plastic square bottle.

Well I took the boat back to the dealer to fix the drive leak and Dennis Moore was correct the drive was leaking from the U-joint assembly.

They replaced the entire u-joint assembly and had me back in the water in two days. All work was covered under my extended warranty.

Re: Drive Lube Leak
 

Well after some 50 hours or running between end of last year and beginning of this year I have a drive oil leak again. This time the extended warranty is expired and boat is now in rack storage. Oil is leaking into bilge with no signs of oil outside the boat or milky oil in the bottle. Time to stand on my head and find leak, I'm hopping it's the bottle or hose connecting the bottle to transom

Re: Drive Lube Leak
 

bc,
if this is an XR drive, they have a tendency to push the seal out of the retainer. There is a kit to replace the retainer and seal that fixes the problem. Do the presure test that Dennis talked about. That will find the leak...

Dick
Good luck!

Re: Drive Lube Leak
 

Okay, this might be a dumb question but what type of pump do you use to pressure test the system like Dennis talked about?

Re: Drive Lube Leak
 

Where did the post go with the link to the valve?