Mercruiser 3.0L Drive lube refill

Hi all, newbie here just own a boat. My drive lube reservoir is empty after a few hours drive. is it normal? Please show me how to refill it. Thank you so much for all your helps. I want to take it out this weekend. Will it safe to run the boat with the drive lube reservoir (monitor) empty. Thank's again.

Re: Mercruiser 3.0L Drive lube refill

The lube monitor going empty is not good, if the gears in the upper unit go without lube, it's going to eat them up and you'll be looking at a very expensive repair.

I would remove the vent plug in the upper unit to see how full the drive is and if it's been run low (use a plastic zip tie as a dip stick if the lube isn't at the hole, it should be), then drain the drive to see if the lube is milky and if water comes out. I think you'll see water and milky oil come out and this needs to be repaired ASAP. If you run the boat with a leaky drive, you could be looking at replacing the drive.

Also look for metal in the drained gear lube, a little extremely fine stuff is normal, but a LOT, or flakes, or chunks is a bad thing.

Re: Mercruiser 3.0L Drive lube refill

As stated, not normal. There is a problem . . . the thing to do is re-fill the reservoir (you don't really need help in filling it) . . . and see if it continues to go down.

If it does, then look for where it went . . . either in the boat or in the water. Neither is good, but in the boat may actually be cheaper to fix.

Let us know how it goes.

Re: Mercruiser 3.0L Drive lube refill

cugiadatinh said:

Hi all, newbie here just own a boat. My drive lube reservoir is empty after a few hours drive. is it normal? Please show me how to refill it. Thank you so much for all your helps. I want to take it out this weekend. Will it safe to run the boat with the drive lube reservoir (monitor) empty. Thank's again.

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Take cap off, fill to full line w/ Mercuiser High Performance gear oil, put cap back on.... Or am I missing something here?

Re: Mercruiser 3.0L Drive lube refill

cugiadatinh said:

Hi all, newbie here just own a boat. My drive lube reservoir is empty after a few hours drive. is it normal? Please show me how to refill it. Thank you so much for all your helps. I want to take it out this weekend. Will it safe to run the boat with the drive lube reservoir (monitor) empty. Thank's again.

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Ayuh,.... Welcome Aboard,.... Nope, Not normal...

When was the drive last serviced,..??

If it's Leakin',... ya gotta find, 'n fix the leak 1st...

Re: Mercruiser 3.0L Drive lube refill

DON'T just refill the reservoir if it's been run dry!

If the reservoir is dry, the upper unit could be low or empty and it's not going to get refilled by putting lube into the reservoir. Well, it will eventually, but running the boat and letting air burp out of it when it gets hot and suck the lube back in when it cools, after several cycles it might put lube back into the drive, but you could also tear up the gears int his time also...

Re: Mercruiser 3.0L Drive lube refill

All good points by the guys but! there has to be a witness of lube somewhere bilge, water, ? As stated drain it and remove the drive then pressure and vacum test ther after to find the source of the leak use soapy water in a sray bottle while under pressure to ffind bubbles and the will lead you to possible problematic area. Have u noticed any dark lube in your bilge and or a oil slick around the outdrive while in the water? Post back with reults. Good luck!

Re: Mercruiser 3.0L Drive lube refill

cugiadatinh said:

Hi all, newbie here just own a boat. My drive lube reservoir is empty after a few hours drive. is it normal? Please show me how to refill it. Thank you so much for all your helps. I want to take it out this weekend. Will it safe to run the boat with the drive lube reservoir (monitor) empty. Thank's again.

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Lots of good advice already.... but let's go back even further. You are a newbie boat owner. is this a brand new boat? If so, then you can ask the dealer the question about the reservoir. Maybe the shop (or PO) did not fill the drive properly and you are seeing the reservoir makeup the loss.
If this is not a new boat, and you don't know the maintenance history, then you should seriously consider the recommendation to remove the drive, check to see if the oil went into the u-joint bellows. Is the boat out of water now? are you seeing any drive oil on the ground under the drive? While the drive is off, you do your impeller changeout (when was the last time done?), the recommended lubes to the u-joints (if serviceable), and the ever-so-important pressure test of the oil-side of the drive. There is just too much at risk to go out with unknowns.
Best of luck and let us know what you find. At a minimum, please tell us more about your engine and drive (year, type, serial numbers, recent maintenance performed, etc). Always helps.

Re: Mercruiser 3.0L Drive lube refill

Since it may have been low for a while (possibly since initial burping after fill up) and you just never noticed it (Tsk, Tsk. Make a check list with drive lube level being one of the checks), Pressure test the drive and if pressure is good try this 1st before tearing anything apart.

1. Remove plug from bottom fill port on drive unit and see if any milky oil / water comes out. If just normal looking oil, then install the Merc oil pump in the hole. If milk or water comes out, you got problems Lucy and off to the shop ya go with it.

2. Remove the cap on oil resevoir, remove the vent plug from top section of drive. If oil comes out of the vent plug, your drive "probably" survived and put the plug back in.

3. Pump fresh oil into the drive as in a normal refill, If vent plug is out, then till it comes out the drive vent plug.

4. Put vent plug in the hole (if it's out) and continue pumping till oil starts filling the resevoir. Calculate how much oil you put in to drive when it came out the vent. If zip, or just a tiny bit, then drive is probably OK.

5. Top off the resevoir as needed and put cap on.

6. On the muffs, run her till the drive starts seeing some heat from the exhaust and spinning the gears and see if you see any leaking at all on the drive and inside where the hose comes thru the transom. Also check that oil level does not drop, as you should be pretty full, at this point.

Re: Mercruiser 3.0L Drive lube refill

Stop!!! Halt!!! Do not Run Engine!!! no oil in resevoir could me low or no oil in outdrive OUCH!!! That will cost you a lot of money.
With the right fitting for the oil pump you can refil oil from the bottom of the outdrive. and see if you have any leaks.

Re: Mercruiser 3.0L Drive lube refill

Was the alarm going off on the boat? If not, you might want to check if the drive lube level monitor was disconnected too.

Re: Mercruiser 3.0L Drive lube refill

BIGALF said:

Stop!!! Halt!!! Do not Run Engine!!! no oil in resevoir could me low or no oil in outdrive OUCH!!! That will cost you a lot of money.
With the right fitting for the oil pump you can refil oil from the bottom of the outdrive. and see if you have any leaks.

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See post right above yours.

What if your reservoir is near empty, the alarm is going off, but your boat is in the water. If you're not supposed to run your boat, how do you get it to the shop? I am wondering if my guy drained the lube for winterizing but didn't refill. Not seeing fluid in engine area. Mercruiser 325 in a 2003 Crownline 21 foot boat

Oden Bay said:

What if your reservoir is near empty, the alarm is going off, but your boat is in the water. If you're not supposed to run your boat, how do you get it to the shop? I am wondering if my guy drained the lube for winterizing but didn't refill. Not seeing fluid in engine area. Mercruiser 325 in a 2003 Crownline 21 foot boat

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Please start a new thread. This one long dead.

Near empty is not empty. The alarm means it's time to fill the lube tank. Also you should find out where the lube went, Lower unit may resealed.

Closed.