Driveshaft Yoke seal replacement

further

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Just picked up my new to me 2004 Chap Sunesta. Dealer I purchased from was supposed to go through everything prior to sea trial which we did yesterday... During the sea trial, the boat bogged bad and the notorious fuel pump whine ensued... Luckily, they had 5 in stock so they took the boat back and installed a new pump... Put the boat back in the water and all good.
A little more history... Over winter, after I made the deal, I checked on the boat monthly (to make sure all was in order and just to visit), i noticed gear oil leaking at the prop shaft... Told the dealer that the prop shaft seal was leaking. They had their mechanics replace the prop shaft seal and in doing so broke the bearing carrier so installed a new one with new seals. Leak fixed - all good.

So after all this, I get the boat home yesterday and start tearing into the outdrive to replace the bellows (I want fresh bellows and impeller prior to dropping it in the slip for the season). Pull the outdrive off and the thing doesn't look like its been removed in 10 years.... Shame on me for not looking at it closer during the sale but I was getting a good deal and they assured me they would go through it all. Anyway, once outdrive removed, the ujoint bellows had a bunch of gear oil in it. So I decided to check the level of the gear oil and it was all the way to the top of the dipstick - uh oh.... Opened the vent screw and a ton of gear oil came out... The vent screw was jammed and I had to get creative to free it up so that tells me they didn't even open it when they refilled and probably didn't drain the old oil. Very annoying...

Anyway, there is no water in the oil, not milky at all and no metal shavings.... Drive shifted very smooth during sea trial and no abnormal noises. I'm now draining all the oil and will do a pressure and vacuum test but suspect the u-joint/driveshaft yoke seal probably let go do to it being overfilled and leaked into the ujoint bellows.

I've already sent photos and videos to the dealer (i've been documenting as I go along) and he's acknowledged that its not acceptable and has already offered to come pick up the boat and fix it, but my issue is that he is an hour and half away and if I bring it back I'll likely not get it back for weeks due to the time of year. Dealer has been good thus far replacing the prop shaft seal and bearing carrier as well as fuel pump assembly all on their dime...I've got a call scheduled with him later today to discuss and will likely just ask for either a check to cover the costs he would incur for doing this work and attempt to do this myself or for him to send a mechanic here to do the work (which is unlikely, but I can hope).

So question is, how difficult is it to replace this seal? Straight forward? The alignment is also off... Gimbal bearing seams to be ok though... but I may change it out anyway to be sure.
Sorry for the long rant... Thanks for the input in advance.
 

further

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Update... pressure is holding at 15psi for over 30 minutes now. I’ve been reading that if the drive is overfilled, oil can bypass the seal? Is the seal blown? I guess if it’s holding, I should be good to go?
 

muc

"Retired" Association of Marine Technicians...
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You might want to do the test as described in the manual.
Completely drain all oil first.
Pressure Test
1 Attach pressure tester to oil level hole.
2 Pressurize sterndrive to 3-5 PSI.
3 Rotate propeller shaft and u-joint shaft to check
sealing. Wiggle,push,pull and do the shifter to.
4 If pressure loss is indicated, use a soapy water
solution to find source of leak. Make necessary
repairs then repeat test.
5 If pressure loss is not indicated, increase
pressure to 16-18 PSI.
6 If pressure loss is indicated, use a soapy water
solution to find source of leak. Make necessary
repairs then repeat test.
7 Drive must not lose more than 1 PSI in
3 minutes.
8 Drive must pass pressure test before making
vacuum test.
Vacuum Test
1 Attach vacuum tester to
the oil level hole.
2 Pull vacuum to 3-5 inches of mercury.
3 Rotate propeller and U-joint shaft to check
sealing. Don't forget the shifter.
4 If drive does not hold vacuum, apply gear oil to
seal surfaces to find source of leak. Make
necessary repairs then repeat test. No loss of
vacuum should occur on low vacuum test.
5 If vacuum loss is not indicated, increase vacuum
to 14-16 inches of mercury.
6 Rotate propeller and u-joint shaft to check
sealing.
7 If drive does not hold vacuum, apply gear oil to
seal surfaces to find source of leak. Make
necessary repairs then repeat test.
8 Drive must not lose more than 1 inch of mercury in 3 minutes

Yes oil can bypass the seal without ruining it.

Replacing the seal is something that should be done in a shop.

Would think they might be happy to pay you to do the job ------- that way if something goes wrong ------- they are off the hook!
 

further

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Thanks for replying Muc,
Yes I followed the testing procedure in the manual - followed the instructions and then left 17 psi pressure overnight and it held steady - no lose at all. My vacuum gauge is busted so couldn't do that test - but since it held on pressure, is vacuum absolutely necessary? As mentioned previous, the oil was totally clean with no milkiness/water and we had it in the water for a good 2 hours for the sea trial.

On another note, as mentioned in my original post the alignment is off - I was able to slide the alignment tool in but it required quite a bit of force so I will be adjusting that... (never done that before but sure I can figure it out). Should I change out the gimbal bearing as well? There was no noise during sea trial and it appears sound when visually inspected and spins freely.
TIA
 

BRICH1260

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I would probably take the boat out and run it for a couple hours then take it back home and pull the drive to see if the oil in the bellows returns. Hopefully it was just overfilled. If the gimbal is smooth, I would probably not replace it now, maybe after the season is over.
 

muc

"Retired" Association of Marine Technicians...
Joined
Jul 7, 2004
Messages
2,170
I would probably take the boat out and run it for a couple hours then take it back home and pull the drive to see if the oil in the bellows returns. Hopefully it was just overfilled. If the gimbal is smooth, I would probably not replace it now, maybe after the season is over.

I agree with this. I've had more than a few drives that will pass a pressure and vacuum test but still leak or get water in the lube.
 
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