9.5 lower unit leak

[stl]

The motor is a 1965 Johnson 9.5 hp. Last night I noticed a little gear oil dripping from behind the prop. I guess a gearcase seal is in order. How hard of a job is this for a novice? The service manual and exploded diagrams have got me a little intimidated. But a 75 dollar and hour service charge has me intimidated as well. I have only done carb rebuilds and waterpumps, head gaskets and simple stuff like that. The lower unit seems pretty technical. Do you have to completely take the gearcase apart including pulling the drive shaft to re seal. Can someone give me a little insight. I have feeling I am in over my head with this one. Thanks

 

[ezeke]

Re: 9.5 lower unit leak

Because the gearcase can be split, it is not terribly difficult and requires only a seal kit and a few tools. Before you do that, however, it would be a good idea to have the gearcase pressure tested to determine the level of the problem, if any.

 

[stl]

Re: 9.5 lower unit leak

Does the drive shaft and gear assembly have to be totally dismantled? Seems like a whole lot of parts that have to go back together perfectly. What about the upper and lower seal I think I have heard the term barrieng carrier before. Do you need a special tool to remove and replace? Or should I even mess with them? I am still trying to decide whether to let the shop handle this or try it myself.

 

[Evinrude Boater]

Re: 9.5 lower unit leak

Why don't you take off the prop and see where the oil is coming from. There's a seal on the prop shaft and there's an O-ring on the case. It could be either or both. If you've taken carburetors apart you shouldn't be afraid of the gear case. They're as simple as kid's toys back then. Photograph the disassembly steps and lay out the parts in order as they come off and you'll be sure to get it back together the same way.

 

[ezeke]

Re: 9.5 lower unit leak

Drain the gearcase and put 10 PSI air pressure on it through either the drain hole or vent hole. If it holds that pressure for fifteen minutes, you should be OK. If not, repressurize and submerge the unit so that you can spot the leaking air bubbles.

The drive shaft simply lifts out when the water pump is removed, so the driveshaft seal can be replaced without a tear-down. The prop shaft seal and the shift rod seal require disassembly.

You must have the repair kit and the proper sealer to do the job correctly. The only necessary unusual tool would be a hand impact driver.

 

[R.Johnson]

Re: 9.5 lower unit leak

On this model engine, if you take the gearcase apart, check the driveshaft where at rides on the upper, and lower bearing. If like most, it could be badly worn, and make the drive shaft hard to seal.