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Out drive oil leak

izdbye

Member
"Hi guys. I have done lots of

"Hi guys. I have done lots of reading over the past year on this site and have learned lots. I now find myself in need of some advice from some of the resident experts. I have a 2005 Bayliner with a 3.0 Mercruiser with an Alpha 1 gen 2 out drive. Late in the summer I had to start adding gear oil to the monitor on a fairly regular basis. In the middle of September I decided to drain the gear lube and start trying to find the leak. There was no water in the gear lube when I drained it. I pulled the water pump housing and discovered some oil around the driveshaft seal. I changed the drive shaft seal, carrier o-rings, shift shaft seal and also the quad seal that goes between the upper and lower gear case. I filled the out drive with oil and assumed that the problem was fixed.....wrong assumption...the next morning there was a puddle of gear oil on the floor beneath the out drive. It seemed to be leaking from one of the drain holes that are just below and on each side of the shift shaft seal carrier. I pulled it all apart and checked it out again, this time the oil seemed to be leaking from the upper gear case. I pulled it off and changed the drive shaft seal, the o-rings for the crown/pinion gears, the anti-dribble valve seal and I also installed a new upper gear case to transom gasket/o-ring set.
I put it all back together and installed on the boat, filled with oil.....and you guessed it....the next day there was a puddle of oil on the floor. Do you guys have any suggestions as to what I may have over looked? If I need to pressure test the out drive, how do I do that?
Sorry for the long winded post. It is a long winter here in Calgary yet, so I have lots of time to get this figured out. I really don't want to take it in to one of the local shops.
Thanks."
 
"You need to drain the gear lu

"You need to drain the gear lube out of the drive and pressure check the drive. It is the only way to properly tell.

You need a hand pump like one used for inflating bicycle tires but you need to add a PSI guage. One that its range is 0 psi to no more than 50 psi. Or you could use a air compressor line with a the pressure regulator set to 20 psi max!!

The outdrive should be off the boat, drained of oil and one of the drain/vent screws removed. The hole size is 3/8-16 I belive so the end of your pump hose needs a 3/8-16 threaded end with a hole thru the middle. Screw the air supply in and make sure it is sealed either with a o-ring or gasket and pump up or allow ~15-17 psi into the outdrive and listen very carefully. Where ever there is a leak this should allow you to hear the air leaking by.

Question? How were you able to get to the carrier o-ring? WHat carrier o-ring are you refering to?do you have the merc tool to remove the spanner nut that holds the upper carrier in place??

If you have access to that tool than you may be able to get the appropriate pressure checker to check for leaks.

When pressure checking the outdrive should hold the ~15-17 psi with out leaking any air for a very long time. Typically I wait for about 5 minutes and if there is no leak than there is no leak."
 
"Kghost,
The carrier o-ring I


"Kghost,
The carrier o-ring I was referring to is the one underneath the water pump assembly. The only special tool I had to use during the entire process is the huge wrench you need to loosen/re-torque the retaining nut on the upper gear housing that holds the drive shaft/u-joints in place.
I did drain the oil last night and pulled the lower unit. This time I had a light ready to go and immediately looked up into the upper gear case cavity. There was no evidence of any oil leak from above. I immedialely turned my attention to the lower unit and noticed that there was an oily film around the base of the shift-shaft seal carrier. I took it apart and discovered that the o-ring that seals the base plate was "flat". I installed a new o-ring, re-installed the lower unit and filled with oil. I went out to the garage this morning and there was no oil puddle. I am certain the problem has been fixed. I neglected to change this o-ring when I originally installed the shift shat seal.
The only problem remaining is that it is still a very long winter here in Calgary!!"
 
Good news! Boy how often are p

Good news! Boy how often are problems related to a part that costs almost nothing. I've had a few of those.
 
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