Out Drive oil disappearing

[Boobie Trap]

OK, just changed the oil in the out drive a couple of weeks back.

The oil in the reservoir on top of the engine was filled. It is now empty. I have filled it twice and each time with about ten minutes of running, it is empty. I realize that I have a leak but it is not in the bilge nor do I see any escaping in the water in the slip.

Could it be that it is blowing out the lower drain screw when under pressure? There is not oil observed anywhere else and it makes it hard to track down. I am hauling the boat out Friday to see but thought I would see if any ideas are out there!

Thanks.

 

[Don S]

Re: Out Drive oil disappearing

Pull the outdrive, drain the gear lube and pressure check the outdrive.

Does this outdrive, have a make, year, and model number?

 

[Boobie Trap]

Re: Out Drive oil disappearing

MercCruiser BIII 2001 hooked to a 7.4L engine. sorry....

 

[Hank496]

Re: Out Drive oil disappearing

Last year I had the same situation on roughly the same drivetrain 496 MAG/BIII. After a while the oil began appearing in the bilge. It turned out it was the upper seal where the drive shaft goes into the the upper half of the drive. The oil that was draining into the drive shaft bellows took a while to build up enough depth to get past the gimbal bearing and drain down the transom into the bilge. In our case it turned out the shaft was worn and the whole shaft, plus u-joints, and gimbal bearing had to be replaced, about 1.6 boat bucks worth.

 

[Bt Doctur]

Re: Out Drive oil disappearing

You did fill it from the bottom until it came out the top, right?