Lower Unit oil milky after 15 minutes ?

Just_a_Kid · Mar 20, 2004

Hello, I have a Chrysler/Force 75hp yr70? anyways I was testing it out after I finally got done putting a new lower unit on and replacing the pinion gear / I guess I have two questions ... 1. when I was putting the shaft back in .. there is a rubber/metal seal that caps over some bearings right below the pump housing.... was I supposed to pack this a lot with marine grade grease ? Or just lube it up a little w/ some ? 2. After putting in some new lower unit oil and running it for about 15 minutes checking over things while it was sitting in a bucket. I questioned the lower unit leaking at all, so I went to drain it.... what came out looked like bird poop or milky oil. I realize that this is a sign of letting water in through a seal, but how bad does it have to be for it to only take 15 minutes ? I found that the vent screw(fairly long screw) didn't have any kind of seal on the end of it ? Is this the only thing that I should check, or do I need to drop the lower unit .. again ... and check all seals, and repack the gear right below the pump housing ? I am sorry this post is so long, but I just didn't want to drop the l/u again if I didn't have to. thank you in advance for any help on this.

eurolarva · Mar 20, 2004

Re: Lower Unit oil milky after 15 minutes ?

the seal below the water pump does not need to be packed with grease or with any lube. The drain screw you mentioned as being long sounds like the pivot screw for the shifter. the drain screw is about as wide as dime and about half an inch long and is about a 3/4 inch thread. The drain and vent screw are identical in size and should both have washer type seals behind them. When you replaced the pinion gear you should have bought and used a complete seal kit and replaced all the seals in the unit.

Just_a_Kid · Mar 20, 2004

Re: Lower Unit oil milky after 15 minutes ?

wow .... so is the vent screw up above the trim tab ? That might explain why it was hard to get the screw that had a long end on it back in after I had taken it out .... I know what that goes to now.... and man that would have sucked if it didn't go back in correctly because then I would have to drop the lower end to fish it back in there. well I have a bunch of seals and I did use what I could, but I didn't have one for the screw I mentioned above ... so I will have to hunt throught the piles and see if I have one. I do have a new end w/ seal for after the prop that I can put on. for the seal that goes on before you put the lower unit to the trim tab does anybody recomend putting something a little tacky on to hold it in place before seating it because I had a little trouble. ? thanks

Drowned Rat · Mar 20, 2004

Re: Lower Unit oil milky after 15 minutes ?

Just a Kid, Are you sure that pivot screw went back in correctly, You would be very lucky if it did. Usually you would have to disassemble the lower unit to get it back in right. In my manual it says when you remove that screw accidentally "BAD NEWS, VERY VERY BAD".

Just_a_Kid · Mar 20, 2004

Re: Lower Unit oil milky after 15 minutes ?

crap ... well after reading the post about removing that screw ... I though I was toast.... went outside to check if it still shifted in and out of gears ok and still the same as far as that goes..... now the only thing that I am worried about that is if it needed any kind of seal ? I didn't see one on the old one ... or on the one that I have taken out twice (yikes) and put back in.... As far as the seals go ... I did get new seals... but the only one that I haven't replaced is the one for the prop which I can still easily do ... and the one I didn't find a seal for .... the one on the shifting rod (probably not the right name) other than that I found one for the shaft, the one right below the pump housing ... a newer pump housing and gasket and then a rubber gasket for the vent screw. I heard that you have to pump the oil in until it comes out of the vent up top ? is that true .... if so .... if I didn't fill it that far and I ran the motor for about 25 min max .. did I do any damage ?

eurolarva · Mar 21, 2004

Re: Lower Unit oil milky after 15 minutes ?

The attached photo is off a 45HP Chrysler. If you removed the pivot screw you will probably have problems. There should be an oring that goes on the screw. If you cant find one you should be able to get one at a hardware store. The problem is it may seem like it is installed correctly until you are on the water and you shift out of neutral it may not go in gear and if it does it may stay in gear. The pivot screw is suppose to be installed when the unit is tore apart. Maybe you will be lucky. The drain and vent screws should also have gaskets. You can get these at any place that sells outboard motor parts. lower unit picture

Just_a_Kid · Mar 21, 2004

Re: Lower Unit oil milky after 15 minutes ?

wow .... well I for sure did a no no then .... but I guess if it didn't have a seal on it .... then am I risking it by taking it out again ... as I noted earlier I can still shift in and out of gears fine ... but are you saying that I will not notice it until after it is running and in gear ?

Just_a_Kid · Mar 21, 2004

Re: Lower Unit oil milky after 15 minutes ?

I found a link here http://www.outboardrepairs.com/topics/011188.html and it covers if you remove it .... I guess I got lucky both times ... I can still shift it in and out of for/rev so I am good to go ... I guess I just need to replace the seals that I can without screwing w/ this piviot pin .....

eurolarva · Mar 21, 2004

Re: Lower Unit oil milky after 15 minutes ?

You still need to find the leak. I have driven mine for a year now with a leak and finally found the problem and am fixing it. If you are seeing it milky after only 15 minutes it is probably a pretty good size leak. I bought a screw the same size as my drain plug screw. I drilled a very small hole in the middle of it and put a basketball needle in it and sealed it with gasket sealent. Put this in your drain hole and put the lower unit in water and pump air slowly into it with a pump. Look for the air bubbles and that will tell you where the leak is. If you dont fix the leak now you need to make sure you drain your oil after every time you use it and replace it with new oil. Did you verify that there are gaskets on the drain and vent screws?

Just_a_Kid · Mar 21, 2004

Re: Lower Unit oil milky after 15 minutes ?

yah in the drain and vent they have a plastic seal... so I am not sure if that is enough .. maybe not ....

roscoe · Mar 21, 2004

Re: Lower Unit oil milky after 15 minutes ?

Those plastic seals should be replaced every time you remove them. They only cost a few cents, so you can buy a bag of them for a $.

roscoe · Mar 21, 2004

Re: Lower Unit oil milky after 15 minutes ?

You still may not have that screw in correctly. And if you have to put a seal on it, why not do it right. Here are a couple links that may convince you to open it up, atleast to check that it is in correctly. Look at this, and pay attention to what "joker" has to say. http://www.iboats.com/cgi-bin/ubb/ultimatebb.cgi?ubb=get_topic;f=33;t=002037 Another one. http://www.iboats.com/cgi-bin/ubb/ultimatebb.cgi?ubb=get_topic;f=33;t=003429

Just_a_Kid · Mar 21, 2004

Re: Lower Unit oil milky after 15 minutes ?

well guys I thank you for your input .. I checked to make sure that when I shifted that I moved it vigorously up and down to make sure that there was no way it was in wrong ... it goes in forward and reverse and I think I got extremely lucky ... After switching out the rubber seal on the vent screw I had w/ the plastic one that was on the drain .... also replaced the whole piece that fits right after the prop and I had a new seal for that ... appears that it was the culprit ... When taking it off I found water on the inside and also found that the screws came off way too easy .... put it back together and ran it for a good 10 minutes and then drained the oil.... and besides just a shade darker it did not look like a milkshake as it did before ...

roscoe · Mar 21, 2004

Re: Lower Unit oil milky after 15 minutes ?

Hooray!!!

dave in toledo · Mar 21, 2004

Re: Lower Unit oil milky after 15 minutes ?

the firts time i changed my lube i did this, i was lucky and got the shift pivit screw back in and all was well, didnt even know it till next year when i bought the manual, it can happen just not very often, if the thing is shifting, then its ok

glass from the past · Mar 22, 2004

Re: Lower Unit oil milky after 15 minutes ?

OK, I must confess I did the exact same thing last week

. I thought that the screw... well we all know how it happens, long story short, I read this post yesterday, and checked out my engine, didn't start it or nothing, I put it in and out of gear with the motor off. (I was scared after reading this post as well as the follow up posts

) Here were my results, what do you guys think? Neutral: prop rotates freely in either direction, Forward: Prop engages into gear, prop is very hard to turn by hand Neutral: prop rotates freely in either direction, again Reverse: Prop engages into gear, prop hard to turn by hand Neutral (again): prop rotates freely either direction. Seems like it is OK, but I don't know for sure, I don't want to blow up the lower unit, is it safe to fire it up and put it in gear?

glass from the past · Mar 22, 2004

Re: Lower Unit oil milky after 15 minutes ?

Also, one last question with this mess, is it bad if there is lube in this hole?

roscoe · Mar 22, 2004

Re: Lower Unit oil milky after 15 minutes ?

is it safe to fire it up and put it in gear?

Thats your decision.

This screw goes directly thru the lower unit to the shift pivot, so yes, there should be lube in there.

glass from the past · Mar 22, 2004

Re: Lower Unit oil milky after 15 minutes ?

I figured someone would say that.

bradleeson · Apr 12, 2009

Re: Lower Unit oil milky after 15 minutes ?

"resurrected post"

This has happened to me today; though I did not do it, I take full responsibility because I did not explain what to do more thoroughly.

I have not yet tried to fix the issue, but as long as you get it thought the coupler it is okay, right?

Is where you will not be sure if you did it correct be in the fact that you can make it through the first hole and may miss the farther hole of the coupler? Not sure that is possible?

Just want to be a little educated on the subject.....

Lower Unit oil milky after 15 minutes ?

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