changing lower unit lube at 20 degree slant

[eli_lilly]

Hello,

I have wondered this for about a year. Due to my trailer being too long for my boat, I can't tilt my motor in the completely vertical position when I change the lower unit lube. Is it really essential for every square inch of the lower unit to be filled with lube or it is more like I am thinking where it just needs to be filled with lube enough to cover everything?

I could always load my boat at the end of the trailer when I do my lube change if it turns out that the air is a problem or something, but my gut feeling is that it doesn't matter. Any input is welcome.


-E

 

[Silvertip]

Re: changing lower unit lube at 20 degree slant

Can you drop the tongue down as far as it will go so you can get the motor vertical? Otherwise, hook up to your tow vehicle and back onto some sort of temporary ramp to get things high enough. A jack works too!

 

[steelespike]

Re: changing lower unit lube at 20 degree slant

Raise the tongue as far as you can.And go to it.
You might try to measure what you take out and figure if you replaced it with the same amount.

 

[tommays]

Re: changing lower unit lube at 20 degree slant

I back my trailer up on a ramp of 3 2 X10 boards it allows the drive to be level


Tommays

 

[eli_lilly]

Re: changing lower unit lube at 20 degree slant


Good ideas, I never thought of trying to raise or lower the trailer. Thanks everyone, I should be able to jack the tongue up and that will get the outboard level.

-E

 

[Frank Acampora]

Re: changing lower unit lube at 20 degree slant

It is kind of important to have the engine vertical when changing lube: If not vertical, all the entrapped air may not come to the surface and bleed off, thus leading to a short fill. A tilted engine may also not fill fully even though there is no air present. And of course, a tilted engine will not fully drain all the old oil.
The importance of a full fill is that there is an upper drive shaft bearing to be lubricated and this is right at the full level. Some shafts have a groove in them to channel lube upward and some don't. So with a short fill, you run the risk of starving the upper bearing. Many of these bearings come only as a unit with the drive shaft--very expensive.
Do not think though, that more is better. If you overfill the gearcase you run the risk of damaging the seals.
If you have absolutely no way of getting the engine vertical, drop the lower unit and clamp it in a vise--then drain it. This is also an excellent time to check the water pump and change the impeller.

 

[eli_lilly]

Re: changing lower unit lube at 20 degree slant


Thanks Frank, that's exactly the information I was looking for. Also, I completely did not think of changing the lube when I have the lower unit off to do the impeller changes, that will work out fine.

-E