Unknown Gear Oil Leak

"I have a reasonably fast oil

"I have a reasonably fast oil leak emptying out my reservoir but I cannot see how or where. My 2000 Mariah Z238 5.7L has an Alpha 1 gen II recently imported from US with reservoir with no leaks visible along hose or at connectors at reservoir and at transom (all dry). The reservoir empties out in a few hours, but I cannot see where it is leaking out too. I completed an oil change and everything seems fine except the reservoir empties out on completion. No external leaks evident either. I ran it at home for over 30 mins with hose and earplugs and everything seems fine with forward and reverse gearing.
If anyone has any advice it would be much appreciated. thx"

"it has been mentioned on this

"it has been mentioned on this site to do a pressure test with the fluid in to see where it is leaking out, makes sense to me."

"also, I am no boat mechanic j

"also, I am no boat mechanic just guessing, but when you refilled the drive with lube did you fill it from the bottom fill hole just above the skeg until lube came out the vent then replace the vent screw and keep adding lube until it came up in the bottle then topped off the bottle, have seen people just fill lube thru the bottle and that traps lots of air making the fluid seem like its disappearing to nowhere."

"Ayuh,...[b]If[/b] you filled

"Ayuh,...If you filled it from the bottom as noted by gl115,...
I'd guess the input shaft seal is Gone,+ you'll find all the extra oil in the Bellows...

If you're trying to fill it through the bottle,...
You may have already done serious Damage to the gears/ bearings...."

"Thankyou for all of your thou

"Thankyou for all of your thoughts and advice. Bondo, I think you maybe right in saying the input shaft seal(yoke seal) is gone with the extra oil going to the bellows.I did fill the oil from the bottom hole until the reservoir became half filled, then I topped up the reservoir to the fill line. After the gear oil change I recently towed the boat approx 30miles and found on my return an amount of gear oil had found its way under the motor to the bilge area with some oil at the transom area. Im thinking that the position of the boat here at home on my trailer slightly leaning back of level, that the extra oil is stable in the bellows, until I towed it going up and down hills etc has moved it inside."

"Parts are fairly cheap. O-rin

"Parts are fairly cheap. O-ring for a couple of bucks and an oil seal assembly for about $40 - $50. A lot less if you just buy the oil seal but then you have to take out the old one and install the new one on the ring.

http://www.mercstuff.com is a great site to explain the operation and the parts and tools you will need.

If you can pull the OD off yourself and take it apart, you can take the upper into a marine mechanic and he should be able to do the job in a couple of hours book time. Also when you're in there you can replace your water pump impeller assembly and check your gimble bearing to make sure it's well greased. It's a good winter time project once you get the OD off the boat."

Re: "Thankyou for all of your thou

Hi Ashley.
I have a similar problem with my Mercruiser V8 5.7 litre inboard engine. The gear lube in the reservoir is leaking out and ends up underneath the engine in the engine bay, after using the boat and switching it off. I have had it at a boat repair shop five times already and they say that they filled the oil correctly and did a pressure test but they cannot find out where it is leaking.
Have u solved your problem yet? What did you do?
Herman Barnardt. South Africa

Ayuh,.... Welcome Aboard Herman,..... Yer alittle late to this conversation,... 'bout 7 years late,...

Has the hose from the drive to the bottle been checked,..??

My Alpha I developed a leak late last season. I would often notice a sheen of oil on the lake and while winterizing I could see gear oil dripping near the pivot point on the outdrive. I suspected the leak might be a hose connecting the lower unit with the transom but wasn't sure where to start digging.

I had several small issues to tackle so I let the guys at my local shop do the work as their labor rates are cheaper in the winter. When they pulled everything apart they found a plastic 90 degree fitting for the gear lube had cracked and when it wiggled just right it would leak. All the seals checked out on the lower unit so I'm certain my only problem was the fitting.

If your issue is similar, you'll have to pull the outdrive to fix it properly.

KJ

That plastic reservoir on mine was leaking after it wore through. Replaced it with a new one and duct taped the metal bracket to stop it happening again.

Jeff