LU oil is grey!

[eavega]

I have a 68 20 HP Johnson, which I have raised a few issues on here. I have the motor running, and am currently trying to troubleshoot an issue with it not cooling, but now I have run into something else and need some guidance here, too.

I took it out on the lake yesterday for the first time. It ran for a total of about 7 minutes over two hour's time (ran about 3 min, started getting very hot, shut it off, waited for it to cool, then 3 min back to the ramp). I drained the LU oil, and sure enough, what was nice clean LU oil is now greyish-green goo, which I assume is water in the oil. When I filled the oil, I replaced the vent/fill screw washers, so I am going to assume a bad seal somewhere.

I have not pressure tested the LU yet, that is going to be tonight, but I am just trying to get ahead of the game. If I am going to have to crack the gearcase (which I suspect I am) and replace the seals, I just wanted to know how involved this job is? I have read through the procedure in the service manual, and it actually sounds rather involved, plus there is need for three special tools to get this done (seal puller, bushing mandrel, and bushing punch). I can't find a price anywhere for these tools, except for the seal puler; its an aftermarket, and its almost $80. I'm wondering if I should punt on this occasion and get a marine shop to service the lower unit. If the one tool is $80, a seal kit is about $20, what will the entire process set me back?

Any guidance is deeply appreciated. This motor is so close to running well, and in the short time I had it on the back of the boat it really performed outstanding, so I really don't want to give up on this one and have to start over.

Rgds

Eric

 

[jbjennings]

Re: LU oil is grey!

It can be done without all the special tools. As far as the bushing punch, if it's for the shift shaft bushing, you can take a 5/16 tap and tap about 3 good threads in the brass bushing and put a screw in it and knock the bushing out with a 1/4 inch rod from the other side. I got a 10 dollar seal puller from harbor freight and got my seals out. But, you have to be very careful or you could break the housing and you're in bad shape. I kind of rock my seal back and forth with the puller and it usually comes out fairly easily without breaking the housing. (I've never broke the housing--knock on wood). I use a vice to hold the housing and a block of wood on the housing to use for a fulcrum for the puller. You also may have some deep grooves on the driveshaft where the old seal rides and you may need to put a "washer" in your seal seat so the new seal won't ride in the old groove and leak. Or you may even need a new shaft or an ez-sleeve.
It is a PITA job and sometimes it takes me 2 or 3 tries to get it right and it's messy, so you very well may decide to take it to a pro. It stinks to do it yourself and still have it leak with all new seals.
Just some ideas,
JBJ

 

[R.Johnson]

Re: LU oil is grey!

Grey does not sound good, such as silver grey. That can mean metal break down. Something can be wearing out, or breaking down. Does the lube have a rotten egg smell?

 

[eavega]

Re: LU oil is grey!

Grey does not sound good, such as silver grey. That can mean metal break down. Something can be wearing out, or breaking down. Does the lube have a rotten egg smell?

No, not silver grey, but a dull, almost greenish grey. Definitely a rotten-egg smell to it, now that you mention. Is this significant?

I did rub some of the oil between my fingers, and didn't feel anything gritty or solid, so I don't think there was any metal shavings in it.


-E

 

[R.Johnson]

Re: LU oil is grey!

A rotten egg smell means the lube has been over heated. Something is breaking down, or running on a bind, or in other words, alot of friction. These high pressure gear lube's contain sulfhur, that is the smell you are getting.

 

[jonesg]

Re: LU oil is grey!

Someone posted this link for a vac/pressure tester a while back, nifty tool. Usefull for testing seals in a tub of water. or beer, almost as cheap as water.

http://www.thetoolwarehouse.net/shop/MIT-4050.html

I'll be doing my seals soon too,
its got the same eggy smell and cappucino cream.
A local mechanic quoted $350 for the seal job, no thanks.!

 

[eavega]

Re: LU oil is grey!

Okay, so my very friendly local outboard mechanic pressure tested my LU (with that same nifty pressure tester that jonesg linked to) and sure enough, its leaking through the shift shaft seal. The mechanic says that the job would be 3 hours (at $60 an hour) plus parts, but would replace all the seals, so probably about $200. Now, that would only leave me a correctly sealed lower unit which he would guarantee wouldn't leak anymore. He did bring up the point, though that since I didn't know how long it had been leaking, we might tear into the gearcase and find the gears all pitted and damaged, in which case they would probably need to be replaced, as they won't last very long. That's another chunk for the parts (I looked online, and saw the gear sets for like $200), but no more for labor. Given the warning that R. Johnson gave me about the sulfurous smell indicating something may be breaking down, and the fact that I don't know how long the LU was leaking before I got a hold of the motor, I am inclined to believe that I may well find damage to the gears.
I have found another shop that is selling an entire LU from a 67 20 HP, and got a quote for that unit of $195 plus shipping. This LU has been totally re-habbed, and only requires impeller installation and its ready to go. My inclination would be to buy the other lower unit, and keep this one for any usable parts (or attempt the repair and if successful try to sell it to recoup some of my cost).

I'm already into this outboard for almost $500 between parts and initial cost, and the motor runs fine and is good power for my little boat from the very short time I was able to run it. I am at the point, though, that I probably won't be able to recoup my costs should I need to sell it. Even at $700 though, its still a much better proposition than paying out $3K for a new one.

Opinions?

-Eric

 

[R.Johnson]

Re: LU oil is grey!

That gearcase is very basic. With a service manual, it is not at all hard to service. You will need the proper tool's for the seals.

 

[eavega]

Re: LU oil is grey!

That gearcase is very basic. With a service manual, it is not at all hard to service. You will need the proper tool's for the seals.

I have both the OEM service manual, as well as a Seloc manual. Neither one describes the procedure very well, and there is still the issue of not having the proper tools, which I assume will set me back at least $100 if not more. Its a convenient coincidence that JBJ mentions how to get the shift shaft bushing out, since that is what was found to be leaking during the pressure test. I should probably tear apart the gearcase first to assess the conditions of the gears before I make any hasty decisions, though. Do you think I can get away with just replacing the shift shaft o-ring and bushing?

-E

 

[R.Johnson]

Re: LU oil is grey!

You might get away with that. Ask the dealer if they will replace the seal's for you, after you have it apart. They might, if you buy the seals' from them.