496Mag, Dissapearing drive fluid
 

Ok, i have twin 496 Mags, closed cooling, bravo ones.

the starboard motor, looses drive fluid, like 1/3 of the resivor a week. running or not.

I have pulled the resevior, checked for leaks, chases teh tube running from it, to the fitting on the back side of the gible going to the drive. no leaks, or drips stains...... BUT it leaks in the bildge. not out side.


WTF, i am not the only one looking, and not the type people that dont know how to work on a motor. but its like a damn mistory where the fliud is leaking out. SIO much so I am ashamed to ask. But after going though MANY MANY bottles of fliud to make sure its always has some, (dont want to hurt a drive).. I want this fixed.

The port motor looses some but nothing like this........

what am i missing.

For starters, you'll want to pull the stern drive off the back of the boat to see if you have any drive oil sitting inside the u joint bellows. Pretty common for the yoke & seal area to wear out and leak and causing this type of complaint.

http://www.mercruiserparts.com/Show_...ift+Components

Good luck.

It is leaking in the bilge. not in the drive. I literally have put about 5 quarts though the system, int he past season, and its always in the bilge.

Correct, The oil that is sitting in the u joint bellows is leaking past the gimbal bearing & dust/grease seal and spilling into the bilge area. Unfortunately this is common, $$$.

For example,
http://www.sterndrive.com/board/show...646&TopicID=42

Check the sensor on the bottle, I had one leaking & couldnt find it til I put a piece of paper under the bottle & it got wet. The fluid was running down the front of the engine was why it was so tough to find the leak.

I have checked the sensor at tha bottom of the tank,. and SWORE i felt some slimyness to it, but then never figure it out.

will investigate further.

I have removed a Bravo before, but am not an expert, is this seal lakematdue is talking about replaceable by just removing the drive?

Here's the gist of it for you,

http://www.mercstuff.com/yokesealreplacement.htm

+1

I had the same problem. It was the yoke seal on the drive. Common problem on bravos. Leaked into the bellows until it spilled over into the bilge. Drained the drive oil and checked for metal shavings.Pulled the drive- drive fluid everywhere. Sent it to the shop. $300 later I had a leak free drive. Don't let it go. Good luck!

Why dont you start with replacing the bottles anyway.

$75 each

Well talked to a local repair shop, that a buddy of mine works for and his first statement out of his mouth was. "if you cant find the leak, and its going in the boat, its the Yoke seal......"


they want 80 bucks labor to fix the seal, and 15 dollas for the seal its self (that's if I bring them the drive.)

120 bucks labor if i have them pull the drive, fix seal, and reinstall the drive, and fill with new fluid...... 40 bucks difference. + new fliud

Needless to say, both drives are getting, new yoke seals, and drive fluid Friday. The other one leaks, but a lot slower, so he said he can pop the drive off and if its a bad seal then the bellows will be full, and he will know instantly. and then can finish removing and replacing the part.

OK, picked up boat. total was 400 bucks.

They pulled both drives, replaces both yoke seals, and one needed a seal around a shift lever.
Then pressure tested both drives, and installed them, and filled with new fluid and topped reservoirs off. also while they had it off painted top cap , that had the pain coming off.

One seal was torn, and leaking bad, the other was leaking but not as bad, the boots where both FULL of fluid.

so good call guys, and thanks for the help

Not a bad price at all for that sort of work: I have done that job a few times myself and it can be a pain unless you have either a stern drive jack or an engine hoist, or 2 strong friends to hold the drive while you guide it off and on....