upper crank seal

[ultra353]

I just picked up a 1975 evinrude 25 hp. I noticed that it has a little bit of oil under the mag plate and just a bit on top of the plate, this would indicate the crank seal is starting to leak right? Does anyone know if the case has to be split to replace the seal or i thought i read on here the that there is a speciality puller for the upper seal. If it can be pulled without splitting, what do you think a dealer would charge me to replace the seal if i have everything tore down so all he has to to do is use that special puller? Thanks

 

[F_R]

Re: upper crank seal

That is the way to go. It will take him about five minutes, but he probably has a minimum charge of a half hour or so. Whatever he charges, it is worth it. Tearing it all apart just for that would border on stupidity.

 

[ultra353]

Re: upper crank seal

Thanks F_R, i`ll get it tore down and take it to my evinrude dealer.

 

[emdsapmgr]

Re: upper crank seal

I had that same problem on my 1979 35. The upper seal went. Found out the upper crank roller bearing had excess clearance and had to be replaced. These upper bearings tend to go on engines that have high hours and will take out that seal. See if you have any play on the upper part of the crank by moving the flywheel back and forth with your hand. If your bearing has excess clearance, replacing the seal won't be a lasting fix.

 

[mark1961]

Re: upper crank seal

I had that same problem on my 1979 35. The upper seal went. Found out the upper crank roller bearing had excess clearance and had to be replaced. These upper bearings tend to go on engines that have high hours and will take out that seal. See if you have any play on the upper part of the crank by moving the flywheel back and forth with your hand. If your bearing has excess clearance, replacing the seal won't be a lasting fix.

Can the bearing be replaced without splitting the casing? Any special tools required?

 

[F_R]

Re: upper crank seal

With respect to the previous poster's experience, I gotta say that if the bearing is bad, the rest of the powerhead is shot too. The bearing just doesn't go by itself. The crankshaft is the inner race of the bearing. Furthermore, bearing failure is usually attributed to water ingestion into the crankcase. That takes out all of the bearings!

To answer your specific question, yes the case has to be split to replace the bearing (s).

 

[ultra353]

Re: upper crank seal

I checked out the crankshaft bearing play and there doesn`t seem to be much movement, if there is its ever so slight i can`t tell if is the crank or the whole powerhead is moving. how much is considered excessive?

 

[emdsapmgr]

Re: upper crank seal

Replace the seal. It's a cheap fix. If the upper crank bearing has excessive clearance, the seal will fail again. In the case of my 79, the bearing did not fail, but the engine became generally noisy. That's how I found the seal and bearing problem. An OMC Master Tech had me check and replace the bearing-said it was a "common problem". No other internal problems found-just the seal and bearing. Honestly, it was so long ago-I can't remember if I split the case to replace it. I do believe there is a locating hole in that bearing and perhaps a pin in one of the crankcase halves which holds it in place, so it probably needs to be split.

 

[ultra353]

Re: upper crank seal

Ok thanks, i haven`t tried to start it and listen for any excess noise because top cyl had 115 lbs of compression and bottom only had 50 lbs. i pulled the head and the gasket was blown Both cyls look good -no scoring. I resurfaced the head on sand paper to make sure its flat. When i take it up to my dealer for the crank seal replacement i`ll ask the mechanic to check the bearing . Thanks for everyones help