Milky Oil in DupProp DPS

[suparye]

Ok, here goes nothing.

Bear with me for a relatively long story, I need help.

Bought my boat 2 seasons ago, went through all of last season (~100hr) periodically checking my drive oil, no loss of oil, no evidence of milk at all.

Beginning of this season I decided it would be a good idea to change the drive oil (it was pretty black but didn't feel like it had lost its oily properties.)

Well, in the process I ran into the infamous inner prop stuck on the shaft. Had to cut the props off in order to get to the drain plug to change the oil. What a headache. Either way cut the prop off, changed the oil, put on new props and went fishing.

First trip was about 50 miles, got home check the drive oil, and it was milky. Did a pressure test and was able to easily find that my shaft seals were leaking. Looks like i nicked the outside of one with the sawzall while removing the props. Replace all 4 shaft seals and pressure tested again, no bubbles. Flushed to drive twice with clean oil to get any water out, put new oil in and went fishing.

Another 50 miles later I check the oil AND ITS MILKY AGAIN!! I think maybe I did the seals wrong and pressure test them again, no leak no bubbles.

The drive just sat overnight pressurized to 8psi and it didn't budge!

It also holds vacuum.

I DONT KNOW WHAT TO DO NEXT, PLEASE HELP!


A few notes:

I initially thought this was related to removing the seals but is there a chance keeping the drive on the motor over the winter may have caused a leave else where.

Could I have damaged a seal or oring while hitting the props with a hammer to get them off?

What pressure and how long are you supposed to pressure,vacuum test, cant find it in the book?

 

[Don S]

Re: Milky Oil in DupProp DPS

Did you drain the gear lube before doing your pressure tests? 12-15 psi is the test pressure.

Have you checked the bellows for water? If water get's in the bellows, it will get into the drive. The seals are not designed to keep water out, that's the job of the bellows.

 

[suparye]

Re: Milky Oil in DupProp DPS

Did you drain the gear lube before doing your pressure tests? 12-15 psi is the test pressure.

Have you checked the bellows for water? If water get's in the bellows, it will get into the drive. The seals are not designed to keep water out, that's the job of the bellows.

Don,
Yes the oil was drained prior to the pressure test.
I tested as high as 12psi with no leaks, and it has held a vacuum of 12psi for the past 3 hours.

I have not checked the bellow, is this something easily done with the drive on?
Is it possible for the bellows to be the culprit and still pass the pressure test?

Also, in my search for an answer I spoke with a mechanic that told me during filling when new oil comes out of the vent/fill hole to let them oil spill out until no more comes out then give it one more pump and seal vent and dipstick then remove pump and replace drain plug. I did not do this as soon as oils leaked out i plugged it and prolly gave it a pump or two extra.
Is it possible the heat/cold cycle is causing the drive to 'suck' water through the seals?

So lost.

Thanks Don.

 

[Glastron_V210]

Re: Milky Oil in DupProp DPS

While the pressure/vacuum tests were being done, did you rotate all devices, shift input etc?

Mine was great when in neutral, but in forward or reverse the shift shaft seal leaked like a sieve!


Chay

 

[suparye]

Re: Milky Oil in DupProp DPS

I spun the shafts by hand and there were no leaks.
I did not try while in gear, I'll give it a shot today.

Thanks for the tip.

 

[Don S]

Re: Milky Oil in DupProp DPS

I have not checked the bellow, is this something easily done with the drive on?
Is it possible for the bellows to be the culprit and still pass the pressure test?

Yes, just remove the hose clamp holding the bellows to the upper gear box, at the bottom of the bellows, CAREFULLY pry it away from the gear box. If water runs out, you have a problem.
Those bellows are thin and should be replace every other year or so, just to prevent water from getting in there. If water get's into the primary shaft bearings in the flywheel cover, you have to remove the engine to replace them.
You also only have to remove the upper gear box to change the bellow, not the complete drive. Usually takes me about 45 minutes to change the bellows and gear lube in those drives.

 

[suparye]

Re: Milky Oil in DupProp DPS

Okay, I did extended pressure and vacuum test in drive, neutral and reverse. All of which passed.
However I still believe there to be a problem base on how milky the oil was after one trip (albeit was a long one).

I have not checked the bellows yet as I was hoping someone could walk me through it.
It just seems tough to get to with the drive on. Also once I do get it off what says any water in there hasn't run either forwards or backwards giving me a false negative?
(forgive me if that sounds stupid thats the only way I could word it)

I ordered the shift seal today (I read they fail often) and will replace it tomorrow and try another run Sunday. (filling it properly) And if it is milky again I will remove the drive and I guess remove all the seals/ o-rings. I'm out of ideas.

Does VP have a kit that includes bellows, seals, gaskets, o-rings ect that I can purchase instead of piecing it together? If so can anyone hook me up with the part number?

 

[suparye]

Re: Milky Oil in DupProp DPS

Also, in my search for an answer I spoke with a mechanic that told me during filling when new oil comes out of the vent/fill hole to let them oil spill out until no more comes out then give it one more pump and seal vent and dipstick then remove pump and replace drain plug. I did not do this as soon as oils leaked out i plugged it and prolly gave it a pump or two extra.
Is it possible the heat/cold cycle is causing the drive to 'suck' water through the seals?

Does that sound like BS?

 

[Don S]

Re: Milky Oil in DupProp DPS

Also, in my search for an answer I spoke with a mechanic that told me during filling when new oil comes out of the vent/fill hole to let them oil spill out until no more comes out then give it one more pump and seal vent and dipstick then remove pump and replace drain plug. I did not do this as soon as oils leaked out i plugged it and prolly gave it a pump or two extra.
Is it possible the heat/cold cycle is causing the drive to 'suck' water through the seals?

Does that sound like BS?

Yes. When you fill it, check with the dipstick to make surre you are in the safe area on the stick, let it set for a while, 15 minutes or so just to make sure there are no air bubbles in it, Then check the dipstick again. If it's within the safe zone, the level is correct.

 

[Don S]

Re: Milky Oil in DupProp DPS

I gave you wrong info on the bellows before, wrong drive.
For your DPS, you have to remove the outdrive, it should be done yearly and it's not really hard to do except that it's a bit heavy a awkward.

What is the full model number or serial number of your engine? I can get drive info from that and link you to the proper service manual.

DO NOT start replacing seals on the shift shaft if it's not leaking. If it passed the leak test, it's not your problem. You MUST pull the drive before going back in the water.

 

[suparye]

Re: Milky Oil in DupProp DPS

Its a DP-SA 1.95

I guess the drive is coming off then.

Correct me if I'm wrong...
disconnect shift linkage.
remove tilt pistons (just from drive or completely?)
Remove 6 bolts and pull.

Is it that simple?

Besides water in the bellows what else should I be looking for as a culprit?

And what seals must be replaced and what special tools will be required for this?

Thanks in advance.

 

[suparye]

Re: Milky Oil in DupProp DPS

Drive is coming off now, I'll report back tonight