Milkshake in my L/U again!!!

[Cricket Too]

Had my L/U re-sealed in Spring of '08 on my '97 115, ran it all season that year, changed out the L/U oil when I winterized that year and got green milkshake out of the L/U, ( I use HPF).

Took it back to the OMC/Bomby shop after winter, in Spring of this year, they pressure tested it and said it wasn't leaking down at all, they tested it a couple of times. Then they filled it back up with HPF and said there may have just been some residual parts cleaner or something in there after the re-seal. I asked also if they put new nylon washers on the fill and drain plugs and they said they did.

Took the boat out of the water yesterday and dropped the L/U oil......and got mint green milkshake out of it!!!!

Water is obviously getting in, so I don't understand how the pressure test showed nothing. I know the guy who runs the shop through a friend, and although I'm not best friends with the guy, I know that he is honest and the shop has a great reputation, they do a good percentage of the OMC/Bomby warantee work on LI.

I highly doubt this is just a normal way for HPF to look after being run for 40 hours or so, especially since my friend uses it in his twin Johnson 200's and it comes out looking almost exactly the same as it went in the year before, that same deep blue look, a little darker as expected.

So basically I don't know what the hell is going on here.

Am I right in thinking that water is definitely getting in somehow??

I should ad that when they re-sealed the L/U they replaced my fill and drain plug with the Allen head type, not that it makes any difference, if anything I would think the Allen head would seal better as you can snug it better. Again new nylon washers are always used.

Thanks.

 

[jay_merrill]

Re: Milkshake in my L/U again!!!

I'm not enough of an expert on gearcase sealing to have a definitive answer, but I'm wondering if the rotation of the propshaft while under way, is making a difference. It doesn't seem like it should, but I can't think of what else would cause this.



???

 

[psteurer]

Re: Milkshake in my L/U again!!!

Hmm! I thought a mint green color was okay for the used lower unit oil that drained out. It was the oil that turned milky in color that indicated that water had gotten in the lower unit. I would be curious to hear what others know about the milkshake color in regard to water getting in. Maybe there is not a problem here?

 

[Cricket Too]

Re: Milkshake in my L/U again!!!

Well when HPF goes in, it is a deep blue color, it turning mint green in color is a milkshake color in this case. Just a mint ice cream milkshake. It looks like mint green toothpaste almost.

If you use "regular" color gear case lube, dark brown or gold for example, then water intrusion turns it into a brownish milkshake color, like would come out of your's truck's rear diff, if it had water intrusion.

But since this is blue to begin with, water intrusion turns it green. I have seen this HPF come out looking almost as deep blue as when it went in on other L/U's. This mint color has to be water intrusion.

 

[LongLine]

Re: Milkshake in my L/U again!!!

Look at the seat that the fill & drain hole screw seal against. If bent inward, burred or scored from previous improper screw installlation, a store-bought nylon washer won't seal very well.

Tom B.
(LongLine)

 

[tal]

Re: Milkshake in my L/U again!!!

If it leaked no where when they pressure tested it then it has to be coming out of a place where the seal is against turning parts. The places I know of are the prop shaft (horizontal) and main drive shaft (vertical). Chances are it's coming from the seal below the water pump that seals against the vertical shaft. I recently resealed my own gearcase and had to pull it apart again because it was leaking at that seal. Once I installed a new one it quite taking in water/bubbling under pressure test. There is also a small possibility it could be leaking from the shift shaft o-ring.

 

[a70eliminator]

Re: Milkshake in my L/U again!!!

After use the drive cools and a vacuum is generated, the chance for water intrusion increases dramaticaly, a vacuum test should be performed.

 

[Cricket Too]

Re: Milkshake in my L/U again!!!

What should the L/U be vacuum tested to? I have a vacuum tester, guess I will test it in the Spring, although I will have to waste the quart of HPF I put in the L/U the other day.

 

[Faztbullet]

Re: Milkshake in my L/U again!!!

Do you have the standard or "batwing" lower unit. I have seen the following problem on several V-6 lower units. What happens is the speedo passage gets plugged and owner quits cleaning it, when it freezes the water will push the aluminum plug loose under the shift rod cover. It will hold pressure all day long and sloooooooooowly leak vacuum. The heating and cooling from running engine is when water intrusion happens. On the "batwing" unit it has a screw and gasket under the cover so you could also be leaking there also. Remove the water pump and wear plate and apply 10-12 bar vacuum to unit to see if it holds, if not spray white lithium grease(can) around driveshaft as it will seal the leak.. if it stops your at the right place, if not do same to prop seals,carrier, oil fill/drain screws and shift shaft.

 

[Cricket Too]

Re: Milkshake in my L/U again!!!

Thank Faztbullet. I have a standard lower unit.

I paid $600 to have it re-sealed last season and it has yet to not look like milkshake when I drain it since the re-seal.

I think I will take it back to the shop again and be a pest. Luckily I saved the gear oil in a water bottle so I can show them. Whatever they find, they cannot dispute that my gear oil came out looking like melted mint ice cream, since I have it in the bottle.

Thanks.

 

[a70eliminator]

Re: Milkshake in my L/U again!!!

What should the L/U be vacuum tested to? I have a vacuum tester, guess I will test it in the Spring, although I will have to waste the quart of HPF I put in the L/U the other day.

It's a two step process, first pull to 3-5 inches of mercury, then to 15 inches of mercury, no loss should occur on the low test and no more than 1" in 3 mins on the high test.

 

[seahorse5]

Re: Milkshake in my L/U again!!!

Chances are the upper driveshaft bearing is worn and the driveshaft wobbles while the motor is running, thus allowing water to migrate inside. At rest, the seals do their job and will hold pressure when tested. Replace the bearing housing, about $75

Evinrude also came out with an improved oring to seal the upper bearing housing to the gearcase. It is a softer larger diameter oring and is brown colored to tell if from the old style black oring. See your dealer for O-ring, P/N 354731.

 

[Cricket Too]

Re: Milkshake in my L/U again!!!

Seahorse.....The driveshaft does wobble, well it wobbles when I have the L/U down, which may be normal, but it seems like it would wobble when it's back up attached also.

But I asked about that when I had it there, figuring a bearing may need to be replaced, but they told me it was due to the two part driveshaft that they used on these. Is that true?

How difficult is it to replace the bearing housing? Does it involve pulling the driveshaft out, or pressing anything? I will have the L/U down in the Spring anyway to do a water pump, so if the bearing housing is reasonably simple, as well as the new O-ring you mentioned, I would rather just do it myself than take another trip to the shop and have them hold onto my L/U for a week.

Thanks.

 

[tal]

Re: Milkshake in my L/U again!!!

From what I understand, if it's a two piece driveshaft then they should have used the offset/double lip seal for that lower unit. Also, the surface the seal contacts has to be fairly smooth or it won't make a seal. Running it up on a lathe and using a piece of emery cloth or 800 grit sand paper works well. Alternatively, you can get a socket on the end of the shaft and turn it slowly with a drill and polish it that way.

I recently pressure checked a lower unit for my friend and it was leaking out of the top bearing housing seal. The shaft had a vertical "nick" in it where I could hang a finger nail on and I believe this is where the air was bubbling out when the shaft turned. It would bubble out the same spot each time it made a revolution. We smoothed it out some which made it better but never really got it to seal completely. He said he'd just change the oil more often.

I'd take it back to the shop, if they're willing to work with you, and have them run the engine in their test tank with fresh oil then check to see if water got in.