Drive Lube Question

jme097

So after a couple weeks of being in and going for multiple runs, I have noticed my drive lube is low. Before launch, I filled it right to the top line and now after 3 weeks of runs, it to the "add" line. I would say its about 5-10 hours of run time. I haven't noticed any oil in my bilge (front) but just from my 2 minutes of investigation I seen oil on the bottom side of the reservoir where the hose comes into the thread but haven't got to the thorough investigation yet. My question is under normal operation, do you actually use drive lube or in reality it is a closed loop system so there should be no lose of fluid. Correct?  Sounds like a funny question but just curious. 

Serenity

Every year after launch I have to add fluid. It does go down to the add line. My mechanic told me it is the air which was in the drive and lines from the fluid change during the winter layup. Every year I have the drives pulled and pressure tested. I do not have any oil at the bottom of the reservoir though--maybe you spilled a little when filling up?

Dream_Inn

Only reason it should go down is after you've had the gear lube changed &/or outdrive serviced.  I say clean the oil on the bottom of the reservoir and look around the engine to make sure it is not leaking down it. Fill up the reservoir and then monitor usage.  If it drops any more, then you need to start looking where it's going.  It'll either show up in the bilge, water behind the boat, or in the hoses in between (which is where I've seen it go before, eventually making it into the bilge).

aero3113

If you serviced it before you put it in the water it will take a few runs to get the air out if any is trapped.

jme097

Thanks fellas. Yeah I know about the burping. I do have my drive serviced in the fall. I am going to head out to the boat this week and do a more thorough investigation. I do keep an eye on it obviously because I don't want to replace a drive. The oil still looks good (not mily or anything) so I believe I do have a slight leak inside the bilge. Thanks again guys!

Michael T

After service air will burp out and the level drop. If you have a slow leak at the bottom of your reservoir the lube may run down the hose, drip onto the block and evaporate off under heat. Of course your two plugs on your drive are snug? You should not be losing gear lube otherwise.

zaverin1

Air is one allowing the drive to burp
drive will use some fluid
lek round the tank 
lube hose has a hole
check valve bad
drive has a hole but that would have to be big one 
if small leak u will see water in the tank actually

jme097

I think I definitely have a leak. Small but it is there. @Michael T I think you're right. Its running down the 2 littles wires and landing on the block or under the block. Definitely not leaking out of the drive. Both screws are tight and don't have any oil on the water. 

MarkB

If you've serviced your drive, there's no way to get all the air out until you run it. So we say it will "burp" and you might have to top up once or twice. But that's it!  If you have to continously add drive lube every 5 to 10 hours, then that is not normal and likely you have a drive seal that is leaking. The prop shaft seal is the one to check first. You want to fix this as soon as possible, as a leaking seal means water is coming into the drive, and this could cause extensive corrosion. 

I would pull the boat and have a compression test done to find out which seal it is and then replace it.

jme097

@MarkB if I have a prop seal leaking would my oil show signs of water in the reservoir?

Black_Diamond

No, the water will not work its way into the reservoir. 

jme097

Thanks BD. I called the shop that does my drive service. I knew it was a gravity system but was just making sure. Headed to the boat tonight to search in the bilge. Hope its just a hose or fitting!

MarkB

As BD says, no it shouldn't get back to the reservoir, but it will be mixed in with gear lube in the drive shaft itself and turn a brownish color. 

Michael T

Sometimes a leaking drive will show a sheen on the water sometimes not. I had an apha1 that lost gear lube while underway. We looked everywhere for leaks. Then a couple of days later on a calm day I saw a sheen on the water. prop shaft seal.

As others have said make sure water isn't getting into the drive as that's a bad thing.

If the leak is slow and small it could be the epoxy seal that wires on some reservoirs go through. If you suspect that, clean the wires and bottom of the reservoir well. Then tie a new Kleenex all the way around the wires. It will quickly absorb and show any leaks.

Also Look for a sheen on the water if you have the boat out.

jme097

Thanks MT as usual. Just curious, is there anyway to tell if there is water in the drive? Or the old fashion pull the drive and see? It just sat on a trailer in my drive for a month while I was getting it ready and I didn't see anything. But then again, I probably wouldn't until water is introduced (if the drive was leaking)

Cableguy Greg

You have to pull the boat and check the lube at the drive. If you open the filler screw at the top or bottom and it is milky, then there is water in the lube.

Michael T

As BD said water should never migrate as far up as the reservoir and I have never heard of that happening.....if it did your drive would certainly be ruined. The only way I know to test for water in the drive gear lube short of hearing the parts fail is to drain some into a pan and look for contamination.

Al may have some black magic way?????

jme097

MT you're a wealth of ideas lol. Im gonna search tonight and do what you said previously about the bottom of the reservoir. If it is the reservoir itself, then fix that first and keep an eye on it. Maybe I'll pull the boat this weekend and pull the drain plug just to check and be safe. 

Black_Diamond

If you are going to be playing around with the reservoir, take the time to empty and clean it out. You might be shocked at the oil sludge at the bottom. Rinse it with mineral spirits or brake cleaner. 

jme097

So I pulled the reservoir and gave it a good look over. Very little oil on the underside of the reservoir where the barbed plastic fitting threads into the metal fitting. I tightened that a couple turns. Couldn't get a look at where the tube meets the drive at the transom. Any suggestions? I am using the Quiksilver High Performance drive lube which says SAE 90 on the bottle. I measured it out and have lost about 4 oz of lube in the past 10 hours or so 

Black_Diamond

90W is correct. Did you change the drive oil?  If you let the reservoir drain when you emptied the drive you can have a fair amount of air to burp out. 

jme097

I take the boat to have the out drive service done every year. I am 99% sure they do change it as well as the usual inspection of the bellows, etc. I think I'm gonna bring the trailer to the marina on Friday and pull the boat to check the lube just to settle my nerves. I might just be stressing myself out over nothing but better safe than sorry 

Michael T

BTW be very careful when cleaning the inside of the drive lube reservoir. On another thread we talked about and I mentioned that there is a white float in the newer ones that activates a low lube guardian alarm. the float rides on an SS spindle. It is held in place with a SS "E" clip that is easily dislodged. If that clip comes off you must replace the entire reservoir. Putting a rag inside, for example to wipe it clean is asking for trouble. Great care!!!!!!

jme097

Thanks MT. so a rinse flush repeat is the way to go then?

Michael T

@jme097, yeah for peace of mind let some gear lube out. If its discolored you'll need to find the source of intrusion (probably a prop shaft seal) If it's not then it's most likely some air in it from service and it will burp some air and you keep an eye on it and fill it up. Once the air is out and the level stabilizes if it keeps dropping there is a leak or If you can never get it to top-up I think it's a leak. IF it's leaking I'm thinking prop shaft!

Black_Diamond

Always the outside chance of the o-ring bad at the drive attachment point. Be pretty rare for the tube to go bad. 

jme097

@Black_Diamond is that inside the bilge? I tried my hardest to actually see the point where the hose connects to the transom point but just could not get in a good enough position. 

Michael T

I have seen the O ring that BD talked about need replacement.

rasbury

I replaced the prop shaft seal and seems like it went down to the bottom a couple of times in very short order but seems to be holding now..I check it every time I launch. How many times have you re filled it? If a couple then you might be ok- I know I was freaking out.

Michael T

Yeah, when that happened to me once (worse air pocket that usual) I wondered where it was all going but it stopped and remained stable!

jme097

Ras I only have topped it off once so far this year. They did change the lube in October when I had them do my annual drive service. So my normal side of me says just keep an eye on it and relax. But the other paranoid side of me says pull the boat and check the drive lube this weekend lol