Lower unit seals

[medic2051]

Weighing whether to replace lower unit seals on my Johnson 1975 50hp myself, or to pay the shop to do the job. I have a manual, and it shows how to totally take apart the lower unit. I am curious as to how much needs to be removed to replace the seals, and if it is one of those jobs that is better left to a pro with the right tools.

 

[DHPMARINE]

Re: Lower unit seals

medic2051,<br />You lost me somewhere,you've got the manual.That should tell you weather or not you can do it.Main problem will be ... it's been so long since it has been taken apart.<br /><br />DHP

 

[medic2051]

Re: Lower unit seals

Is it necessary to remove the "guts" i.e. drive shaft, bearings, etc.of the lower unit if you only need to replace the seals? My manual shows an exploded view of all the parts, but does not really mention just replacing seals.

 

[alcan]

Re: Lower unit seals

Hi Medic<br />I do not know which manual you have, but I am sure that it covers removing and installing each seal in your L/U as a step in the over-all disassembly and reassembly. This means you will have to read the entire chapter. To answer your question, Yes you will have to pretty much disassemble the entire gear case. At least remove both shafts. As DHP states the toughest part of the job may be disassembly. This can range from a cake walk to the mutha of all pains. Of course your manual is going to show you pictures of a fella working on a brand new unit, using the latest in special tools. Only you know if you can do the job. Can you fab your own special tool if needed? Do you have access to a slide hammer or the correct type pullers? This is how I make this decision. What is the value of the broken thing if repaired? What will it cost to have it repaired? Do I have enough time to make repairs before I absolutely need the thing. Remember it takes at least twice as much time to make repairs at home. Then I figure what do I have to loose, the darn thing is already broke, go ahead and try, it will be a learning expirence.

 

[OBJ]

Re: Lower unit seals

Guys....didn't think you had to take the gear case apart to reseal. The bearing carrier comes out, the seal housing under the water pump housing comes off and the shift rod seal is in the cover plate. Don't have the parts breakdown in front of me here....so if I'm missing something, holler at me...... <br /><br />But do agree with DHP the carrier can be a beotch to get out sometimes.

 

[MarkHPCA]

Re: Lower unit seals

I did my 120 last spring. As OBJ says you don't have to pull everything out. The only part that could present a problem is the carrier, I used a cheap puller with two long bolts to get mine off. It was faily easy, but then my motor has never been in salt water.<br /><br />Good luck.

 

[alcan]

Re: Lower unit seals

Why would someone reseal a contaminated gear case with out cleaning and inspection? A lot of things are possible. Are they good practice?

 

[ED21]

Re: Lower unit seals

Medic,<br />I have the OMC repair manual & the procedure to replace the seals is a bit cryptic. After a lot of review I think I figured it out. A "replacing the seals" section would of been nice. Also there is a nice exploded parts diagram without any of the parts labeled. That took a while to figure out too.<br />Like Alcan said, I'm trying to decide if I can get, borrow or make the proper tools for the cost involved. I'll change to water pump at the same time.

 

[medic2051]

Re: Lower unit seals

Thanks. I agree, the manual is pretty generic for removing everything at once, not just replacing seals. I think I'll give it a go. Anyone know ow much the puller tool runs? Is it a Johnson tool, or an you get one at an auto store? Any tips on reinstalling the seals?<br />Thanks

 

[Indymike]

Re: Lower unit seals

A harmonic balancer puller works along with two 8" long 5/16-18 bolts. Any auto parts house will have the puller and lowes carries the long bolts.<br />You'll need a long extension for your socket to get to the four carrier bolts. Don't forget to change the o rings on the carrier bolts.<br /><br />Mike

 

[OBJ]

Re: Lower unit seals

Point taken and conceded to Alcan.... May as well look at all of it while your in there.

 

[BeenThere]

Re: Lower unit seals

Just replaced mine last month when I replaced my water pump. I found the job VERY easy. I do most of my boating in saltwater but had no problems with corrosion. Actually.... the reason I decided to change mine was ever since I got the motor (1996 200 Johnson OceanPro)I have had water and my lowerunit. Never much, but enough to turn the gear lube gray. So I would change it 2-3 times a year. I've had it to several shops and they alway said it pressure tested fine. But, after sucking some sand I decided to replace the water pump and after removing the old pump I noticed how much seal gap there was around the shaft. So I decided to try it.... Once I found the parts it took ma about 45 minutes. And it looks like I may have found and cured my water in lower unit problem, because after replacing the seal I went trolling for a day and check the lube condition after I got back and for the first time that I can remember it was clear I hope this helps.<br /><br />Don

 

[medic2051]

Re: Lower unit seals

Thanks for the tip. It does sound easy. Did you pull out all the shafts and gears, or just replace the seals?

 

[BeenThere]

Re: Lower unit seals

I just replaced the seal. Very easy to do. Just be sure you clean verything prior to reinstalling.