Alpha one gen 1 outdrive leaking gear oil in engine compartment

richa311

Seaman Apprentice
Joined
May 19, 2015
Messages
43
After my last run out I noticed some oil in the engine bay where the outdrive connects. I'm curious what would cause this? I don't have a remote reservoir for gear oil like the gen 2's have so its not a bad line. I'm guessing a seal somewhere between the top of outdrive and drive shaft but not sure. Any ideas that may help would be great.
 

richa311

Seaman Apprentice
Joined
May 19, 2015
Messages
43
Ok thanks
Is this an easy seal to replace or do I need speacial tools?
Thanks again
 

Bt Doctur

Supreme Mariner
Joined
Aug 29, 2004
Messages
19,093
you don't list a year or if the gear set has ever been replaced. you will need the spanner to loosen the carrier ring, and pull the inputshaft straight out.
Now depending on your gear set, the gears will slide off(old style) or need to be pulled off(new style)
For old style just tighten the nut for assembly, for new style, rolling torque is used .
Press the old seal out of its carrier, press the new seal in the carrier until flush. re-assemble in reverse order.
Check the input yoke for any grooving. there should be none. If there is a deep score, the input yoke needs replacement.
 

richa311

Seaman Apprentice
Joined
May 19, 2015
Messages
43
This is on an 89 Scarab with the 5.7 liter and alpha one outdrive. Pretty sure the gear ratio is 1.47. The boat is new to me so no idea if the gear set has ever been replaced. Gear oil isn't leaking anywhere else that I can see. The gear oil is the color of chocolate milk (90w general purpose gear lube not the green synthetic) so it has some water contamination although not much came out just a very little right at the bottom drain bolt. Thinking maybe the drain and vent bolt gaskets are suspect.
All the bellows look to be in great shape with no evidence of cracking or wear. They actually look pretty new.
 

nola mike

Vice Admiral
Joined
Apr 22, 2009
Messages
5,023
BT already answered your question. Straight forward if you have the old style gear set. I haven't done it on the new style, though it's more involved. I don't know if there's a way to tell which style you have before you get in there...
 

Bt Doctur

Supreme Mariner
Joined
Aug 29, 2004
Messages
19,093
nope, they look the same .if it dosent slide off with hand pressure or if you use a spreader/puller to remove the bearings from the gear you will not see a small inner spacer, just the large outer spacer
I have resorted to using the inner spacer with a new gearset instead of the rolling torque method. I find it works perfectly to have the correct preload.
 

richa311

Seaman Apprentice
Joined
May 19, 2015
Messages
43
Ok thanks for the info. I guess ill pull it off in the next couple of weeks and see what I'm dealing with. At that point ill decide if I should do it myself or have the work done somewhere.
 

bspeth

Senior Chief Petty Officer
Joined
Aug 30, 2013
Messages
756
The oil may have mixed with bilge water,or you may have some water in the UJ bellows and it mixed in there. Either way you are pulling the drive so have a look.
 

richa311

Seaman Apprentice
Joined
May 19, 2015
Messages
43
Ok so I pulled off the outdrive today. It didnt come off easily but with some persuasion its off. The drive shaft bellow was filled with gear oil and a small trace of water. I'm not sure how the water got in from what I can tell the bellows itself is in great shape with no dry rot or cracking.
My gimbal bearing is loud though and will need to be replaced.
So I'll have to order the bearing, transom seal kit, the special retainer nut wrench, and the input shaft seal thats allowing the gear oil to escape the drive.

My problem is I'm not sure what part number that seal is? Is it included in the upper drive seal kit or is it purchased seperate?

Any help would be appreciated I'm looking forward to getting the correct parts ordered so I can get it back together and back in the water.
 

Bt Doctur

Supreme Mariner
Joined
Aug 29, 2004
Messages
19,093
I would recommend the National seal 712250. It is the oem seal that was used in the merc drives.483323VGO
 

Bt Doctur

Supreme Mariner
Joined
Aug 29, 2004
Messages
19,093
if its not the double lip seal I wouldn't use it.Mercruiser tried using a single lip from CR. they were replacing drives under 20 hours from oil loss
 

richa311

Seaman Apprentice
Joined
May 19, 2015
Messages
43
I have no idea if it is or not I can't find anywhere it lists it as a single or double lip.
The seal in question is the sierra 18-2003 that's included in kit. The reviews on the seal are good though.

So I plan on using a rear axle bearing puller attached to a slide hammer to remove the gimbal bearing hopefully that works out ok.
Anyone have any advice or tricks to installing new bearing without the special tool? Thinking of just using a large socket size of bearing and a long extension to bang it in.

I haven't removed the u-joint assembly from drive yet because I don't have the spanner wrench yet. Being an 89 gen 1 does anyone know if it will be the one that the gears will just slide off opposed to having to be pressed?
 

richa311

Seaman Apprentice
Joined
May 19, 2015
Messages
43
I just looked and that national seal is available at local parts store so if the sierra seal dissent look like the one then Ill grab the national seal
 

richa311

Seaman Apprentice
Joined
May 19, 2015
Messages
43
Ok the more I'm thinking about it I kind of wanna replace the u-joint bellows. It does look almost new and I don't see any leaks but I don't see any other way water could have gotten in. Maybe from hosing out the engine bay when I was cleaning the gear oil out?

If i tackle the u-joint bellow can I do it without pulling the bell housing? If I can go without pulling it and saving me from buying the hinge pin tool and having to fight the exhaust bellow on then I may just do it to be sure.
 

richa311

Seaman Apprentice
Joined
May 19, 2015
Messages
43
Well this is definitely turning into a not so fun project. I think ill go home and really inspect the drive bellow really well and make sure I can't find somewhere water could be coming in. Maybe soak the inside with soapy water and spray around it with compressed air. maybe its a loose clamp or one that's not seated well. How likely is it that water could have gotten in from we washing out the bilge? I don't know how easily water would go in that way but I did hose all around the drive shaft on back of motor trying to clean the gear oil when I was tracking down the gear oil leak
 

richa311

Seaman Apprentice
Joined
May 19, 2015
Messages
43
Sorry for all the posts but something else just came to mind. When I separated the drive from the transom there was a large rubber gasket where it fit into the drive bellow. when I 1st saw it I actually mistook it for a piece of the bellow. It wasn't really seated and was in rough shape and nicked up. Would that seal allow water in?
 

richa311

Seaman Apprentice
Joined
May 19, 2015
Messages
43
I got the outdrive done this week. Worked on it a little each day after work. Ended up doing the gimbal bearing, pulled the upper shaft and replaced the output shaft oil seal that was leaking. I also replaced the waterpump impellar and associated seals.
I didn't end up changing the drive bellows I couldn't find any leaks in it. I examined it closely and found no wear or damage.
I think water was either entering the drive from the oil vent plug or the big round seal where the outdrive slides in.
I'll fill the gear oil tomorrow and water test it. Hopefully all goes well
 
Top