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Stern Drive leaks 90w! 3 Steps Forward & 1 Back.

L

LX Kid

Regular Contributor
After my '82 Grady had been sitting for 3.5 years, so many maintenance problems have been identified and fixed. But every time I think I'm about ready to launch something else come up. "This time" it's the MC-1 outdrive. When the outdrive is in the up position all my 90w leaked out of the reservoir and dripped out the upper. I'm "guessing" around the area where the drive enters into the upper by looking at the drip trail. Got any suggestions for me? "More than likely" the outdrive is going to need pulling. Gotta be a seal somewhere up there but unfortunately below the water line.
 
You need to have a professional service your outdrive.

The ONLY way to determine a leak is to drain and pressure check the drive to ~ 15 PSI no more. Should hold for 2 minutes with no leak down.
 
kghost said:
You need to have a professional service your outdrive.
The ONLY way to determine a leak is to drain and pressure check the drive to ~ 15 PSI no more. Should hold for 2 minutes with no leak down.
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Thanks Kghost! Good advice "but" gotta try doing it myself. No extra money laying around for the pro's! Has to be worth doing two or three times to get it done properly. Seems experience cost, "how much do I wanna pay?" LoL Only thing I hate is having to work groveling around in the sand. Guess I'll lay a large tarp down and buy a 4x8 sheet of plywood to lay on top of that. As usual I'll post some pics of the damage I'm doing! Ha
 
Would you think it's "more than likely" a yoke seal? Just by eye balling it "seems" it could be coming from that area. While in there I'll replace all three bellows and check gimbal bearing for smooth operation.
 
kghost said:
AGAIN
The only way to check properly is to pressure check when empty.
Get a bicycle pump and adapt a pressure gage to it and the threads for the drain and vent are 3/8-16
This is what I use for reference on the set up
http://www.explosivepowersports.com/stevens-instrument-gearcase-pressure-tester-s-34/?

gclid=CNHY5IHvvcwCFY5ZhgodX8wCVg
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Ok. I'll do that first before I do anything! I'm going to take the day off from it cause I'm sooooooo frustrated with 3 steps forward and seems two steps back. Maybe, "Tomorrow will be a better day!", as Scarlet O'hara said in Gone with the Wind!

That $145 pressure tester just isn't gonna happen for me. I'll use a little 2 gallon adjustable pressure compressor that I already have. I'll just make sure no more than 2 pounds pressure and use a spray bottle of soapy water to look for leaks. I sure don't want to blow out any seals!!! Bicycle pump would probably even be more safe as you suggest.
 
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This morning I went by "William Harrison Marine Services" and asked what it would cost to get the outdrive properly fixed. He laughed and told me he worked on them for 10 years up North and, when he moved to Tampa, swore he'd never take in a Mercruiser. He did offer some suggestions for me though. He said if I'd remove the outdrive and bring the upper to him he would help me out with replacing seals. He remembered me from years ago, when I first bought the Grady, and gave me a couple of free parts. He said he admired my tenacity! He also told me I have to pressure test before I do anything. Really a nice guy to offer help.
 
If you pressure check it you MUST pressurize the drive to 12-15 psi 15 psi is max.

You will hear the leak believe me!!

So if you use a small compressor the set the regulator to 12-15 psi and see what you find.

Soapy water trick is NOT the way to do this!!!!!!!!!!!!

The merc alpha drive produces ~ 7 psi when running so you need to exceed that to show a defective seal (s). Meaning you may find one with a gross leak then after repair recheck pressure and you may find another.......
 
kghost said:
If you pressure check it you MUST pressurize the drive to 12-15 psi 15 psi is max.
You will hear the leak believe me!!
So if you use a small compressor the set the regulator to 12-15 psi and see what you find.
Soapy water trick is NOT the way to do this!!!!!!!!!!!!
The merc alpha drive produces ~ 7 psi when running so you need to exceed that to show a defective seal (s). Meaning you may find one with a gross leak then after repair recheck pressure and you may find another.......
Click to expand...

Ok! Buddy coming over tomorrow to give me a hand. Gonna move boat to the driveway so I'm not groveling around in the sand. Can't figure out why there is soo much sand here in Florida and being 3 blocks away from the beach! Go Figure!
 
Drained the 90w and machined out a 3/8x16 tpi air fitting to fit into the drain hole to enable an air hose attachment. 12 psi it is then! Tomorrow is only 80% chance of rain! We could "really" use the rain though so I won't complain if it does.
 
UPDATE: Rained all day yesterday so this morning I pressure tested outdrive and found "NO" leaks! I put my finger over the hose I fitted to the drain and it held pressure and didn't bleed off. I then refilled the system with Wal-Mart 80-90w lube, which has an API code GL5. Ran the engine for awhile and then left the outdrive in the up position to see if it leaks out. I will periodically check it out.

Is the upper seal, which seals the lower drive shaft, just for sealing grease and exterior water from entering into the lower cavity? When I ran the engine, with lower all the way down, I noticed the inner prop exhaust was somewhat greasy.
 
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Went outside after sitting for about 30 minutes and found leaks once again. As you can see it's dripping from up high, hits forward stub & nut then running off the cavitation plate. It also is slightly coming out of the pee hole!

What is strange, I just noticed, is the color of the lube which is green from Quicksilver which I drained. When I refilled with Wal-Mart it is the normal amber color.!

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What pressure?

The leaks looks like it may be coming from the shift shaft seal/bushing or the vertical drive shaft inner/upper seal in the upper case.

drive has to come off to repair and special tool is needed to remove and install bushing. or disassembling the upper depending on what is wrong

You can no longer escape the fact that the drive has to come off.

You are looking for answers because you are not doing the testing completely.

WHen the drive is off and under pressure you need to (by hand) spin the prop shaft, put it in gear by way of the shift shaft pointing straight forward and then spin the u-joint assembly/shaft, also turn the shift shaft all the way clock wise and counter clock wise by itself and listen for air leaks
 
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kghost said:
WHen the drive is off and under pressure you need to (by hand) spin the prop shaft, put it in gear by way of the shift shaft pointing straight forward and then spin the u-joint assembly/shaft, also turn the shift shaft all the way clock wise and counter clock wise by itself and listen for air leaks
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In a few minutes I'll go outside and see about pulling the outdrive off and take it to the Marine Service referenced in post "7" above and see what he can do for me. He said to just bring him the upper.

Thanks
 
put your shift control in forward gear and make sure it is or drive will not come off!!

remove the trim rams from the drive.

remove 6 nuts and hope it come away from the gimbal housing.

Bring the whole drive.......it needs to be looked at.....
 
Pulled the lower off and am waiting for the WD-40 to soak in around the 6 stud shafts as they are corroded. Only one appear to be lot of corrosion. Last time it was off probably no grease was put on the stud shafts. There was 90w on the water pump housing and shifter shaft areas. Took pics as best I could.

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Pulled the lower off and am waiting for the WD-40 to soak in around the 6 stud shafts as they are corroded. Only one appear to be lot of corrosion. Last time it was off probably no grease was put on the stud shafts. There was 90w on the water pump housing and shifter shaft areas. I didn't take a pic of it but there is exhaust carbon on the drive shaft. Took pics as best I could.

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Here's a pic of the lower shaft and plastic water tube with carbon on them. Could this be because I ran the motor without having the foot all the way down? I also reused the o-ring between the two halves around the lube path hole. I think the upper is leaking 90w somehow and running down the shaft onto the top of the water pump.

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Pulled the upper this morning and find that I have water mixing with the 90w. Probably as "Kghost" said it could be the upper inner/outer seals. Cleaned the water inlet as it looked considerably closed down by corrosion. I will order a complete set of gaskets, seals and bellows and replace everything. I'm "pretty sure" my upper is a MC-1 and is also called a Type I.

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Against advice to let a pro do it, I ordered the seals, o-rings and the spanner wrench to give it a try myself. Watched a YouBoob video and it looks pretty straight forward about the process including the inspection and cleaning of seal surface areas. Also am changing the bellows for the shift cable, as it was split and exhaust tube. My exhaust has an open ended tube instead of a bellows.

I'm going to use a flexible trombone cleaning brush and send it up the water hose to clean some obvious corrosion build up as you see in the above photo.

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Received all my gaskets and seals in the mail today. Now all I'm waiting for is the spanner wrench for disassembly.
 
My wrench came in last Friday and will hopefully start on upper seal & o-ring replacement tomorrow. I do have a question concerning the upper and lower cup seals. As far as I can ascertain, the upper cup seal, the "cup end" points upward and the lower "cup end" of the seal points downward towards the lower. Am I correct? In automotive engine work cup seals are just the opposite.
 
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Thanks Kghost! Just as I thought but never hurts to ask. Last time I replaced the "lower" cup seal, I put it in "opposite" as pictured, and don't know if maybe that was part of my water in upper problem.
 
Took the upper apart and found the bearing also need replacing. They are not growling or rough but better to do it now instead of going back in later.

DOES ANYONE KNOW WHO'S GOT THE BEST DEAL FOR ALL THREE BEARINGS?

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Once I get the bearings off I'll put the shaft on my lathe and polish the end that will pass thru the cup seal. Just called iBoats parts department trying to get the needed bearings.

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3 steps forward and another step back! Don't have the bearing separater or race puller to do the job. Thinking of throwing whatever seals and o-rings I can get to and put it back together and hope for the best. If it doesn't leak water into the upper I'll just use it till they fail and worry about it then. I found another whole outdrive for $400 and is guaranteed for 30 days. This might be the way to go for now.
 
LX Kid said:
Once I get the bearings off I'll put the shaft on my lathe and polish the end that will pass thru the cup seal. Just called iBoats parts department trying to get the needed bearings.
Click to expand...

"Actually I called MarineEngine for the parts and not iBoats."
 
LX Kid said:
3 steps forward and another step back! Don't have the bearing separater or race puller to do the job. Thinking of throwing whatever seals and o-rings I can get to and put it back together and hope for the best. If it doesn't leak water into the upper I'll just use it till they fail and worry about it then. I found another whole outdrive for $400 and is guaranteed for 30 days. This might be the way to go for now.
Click to expand...

I went over and looked at the outdrive that was being sold and for the money it looked pretty good. He offered to replace all the seals in mine, for $100, instead of buying his unit. He's also is giving me a 30 day guarantee. Sounded like a good deal and am going to pick it up tomorrow or the next day.
 
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