Gear oil leak

[josh1981]

So I was looking at the boat today. (It is winterized and put away for the winter) I noticed a small amount of gear oil leaking from the out drive. It is coming from a drain hole (called a Gear Housing Water Drain Hole in the manual, Manual #14 page 1B-17) near the top of the lower housing.
Bottom picture in this link points to the hole.
www.mercstuff.com/drive_idgenII.htm

Anybody know what I need to fix?
I had the whole drive off last year, did the water pump and all o-rings and gaskets that came with that kit. As well as all new bellows and gaskets to the bell housing.
Thanks in advance

 

[Bt Doctur]

Re: Gear oil leak

upper drive shaft seals, lower shaft seals, quad seal missing. only way to find out is disassembly and inspection.

 

[Don S]

Re: Gear oil leak

Before you take it apart, Drain the gear lube and pressure test the drive to find the leak.

 

[josh1981]

Re: Gear oil leak

Before you take it apart, Drain the gear lube and pressure test the drive to find the leak.

So I pull the drive off and do a pressure test. How do I know which seal is leaking? Should I just replace them all? Are they fairly easy to replace?

 

[achris]

Re: Gear oil leak

So I pull the drive off and do a pressure test.

Yes.

How do I know which seal is leaking?

That would be the one that is letting the air out. You can either listen as you should be able to hear it, or use soapy water and see which seal is making bubbles.

Should I just replace them all? Are they fairly easy to replace?

I would split the drive and test each half separately. To do that you'll have to work out some way of sealing the oil passage between the halves. (I have some bits of rubbish I made up for that). That will also give you access to the seals you can't get to from the outside when the drive is fully assembled, like the shift shaft seal, the bottom seal in the top box and (if you have removed the water pump impeller and base plate) the drive shaft seal in the lower box.

Easy to replace? Depends on which seal's leaking.... Also check the shaft that the seal is running on, possibly it's got a groove in it and that's why the seal's leaking. If that's the case, you need to replace/repair the shaft too....

Replace them all? Up to you. On a Gen II, I would just fix the one that's leaking, probably the shift shaft seal in your case (but that's just a guess )...

Chris........

 

[josh1981]

Re: Gear oil leak

So if it is the Shift shaft seal. I would need to get the Shift Shaft Bushing Assembly (p/n 815921A2 ) which includes the bushing assembly, oil seal, and 2 o-rings. And also a new drive install kit ( p/n 94996Q 2 )
Sounds like hopefully it is just the shift shaft seal.

 

[achris]

Re: Gear oil leak

Wow up boy!.. Do the pressure test FIRST, then we talk about what's needed. I just threw that in there as a possible first place to be looking (now I wish I didn't!). As for the bell housing gasket kit, yes, regardless of anything else you'll need one of those.... But let's get that test done FIRST!

 

[paultjohnson]

Re: Gear oil leak

So if it is the Shift shaft seal. I would need to get the Shift Shaft Bushing Assembly (p/n 815921A2 ) which includes the bushing assembly, oil seal, and 2 o-rings. And also a new drive install kit ( p/n 94996Q 2 )
Sounds like hopefully it is just the shift shaft seal.

Actually, hope its just that the quad seal didnt get replaced/reinstalled ??? The little o-ring thing that goes around the oil passage from the upper to the lower.. Its commonly overlooked/ forgotten on reassembly...Look it up, starboard side, just fwd of center

 

[dubs283]

Re: Gear oil leak

Actually, hope its just that the quad seal didnt get replaced/reinstalled ??? The little o-ring thing that goes around the oil passage from the upper to the lower..

if that were the case the drive would have been toast a long tima ago, unless of course the operator was constantly fillig the lube monitor while underway

to o.p. - stop guessing as to which seal(s) you need - first step in this process is to pull the drive off the boat and pressure test it (as suggested in earlier posts), look/listen for leaks with soapy water spray

 

[paultjohnson]

Re: Gear oil leak

if that were the case the drive would have been toast a long tima ago, unless of course the operator was constantly fillig the lube monitor while underway

Perhaps, but not necessarily. How do you know he even ran the boat after he had it apart ? But then,I have a Gen 1 Not a 2, so I am not as familiar.

 

[wellcraft-classic210]

So many seals and so little time;

So many seals and so little time;

I recently had to find a slow leak in mine after resealing and failing a pressure test. Soaking the whole drive under water with pressure was invaluble as the bubbles tell all and its hard to spray soapy water on all the areas.

This also reienforced the need for a pressure test after any servicing as it can save a drive from potential problems.

 

[josh1981]

Re: Gear oil leak

Ok, ok... I will do the pressure test asap. See what I find.
After I put everything back together last year I did have the boat out a number of times. Did not notice any problems and did not have to add any more gear oil.

 

[wellcraft-classic210]

Re: Gear oil leak

Leaks on Alpha and pre Alpha drives often allow water in as well as oil out depending on the internal pressure in the outdrive. This varies with temperature and related expansion of the oil & air inside. Oil discoration is something to look at as well as level as it indicates water has entered the drive.

One possible source ( As in 1 of many )
Any water in the drive shaft bellows area can be forced into the drive as the shaft spins resulting in an over level conditon of the drive fluid.
This can cause excessive pressure, a resulitng oil leak and discolored oil. The overlevel condition can be seen when the oil level plug is removed. After noticing oil dripping on a hot day from the water drain hole you mentioned above on my Alpha it sprayed a surprising amount of discolored oil when I removed the top plug.
I was then able to celebrate with a few descriptive words and the thought of another big project. This amounted to; New bellows, Reseal the outdrive that failed pressue check at prop shaft seals and a new water pump while I was at it.