removing lower gear case to service water intake tube.

[wcasey5]

I think I have a leaky water intake, I bought the seals and I'm ready to separate the upper and lower. I also need to adjust my shift rod. Is there a gasket between upper and lower? Any tips on separating, I have removed the drive from the boat. Any tips on putting the two halves together again? I have the manual, but I would like some experience. Thanks.

 

[jerryjerry05]

Re: removing lower gear case to service water intake tube.

No gasket.
Why are you adjusting the shift rod???
Usually it's set and not needed to do any adjusting?
If it's not shifting correct.The Bellcrank might be corroded/bent and need cleaning.
Or any number of other things.

To seperate,drain the gear oil, after removing all the bolts and stuff,turn the shift rod to one side or the other and lift up the top.
To reassemble same procedure,just backwards.
You have a manual?
You know the proper way to fill the gear oil?

 

[wcasey5]

Re: removing lower gear case to service water intake tube.

Yes I have the Manual, and I've successfully changed the oil in the past, from the bottom. The shift rod looks like it is out of adjustment, because when I did the lower shift cable, it wasn't coming out of gear when the bell crank was in the 90 degree position, it needed to be down slightly to be in neutral with all other things being equal. It shifts fantastic, I just want to make sure everything is correct.

So some RTV on the joint between upper and lower?

thanks

 

[Idlespeedonly]

Re: removing lower gear case to service water intake tube.

No rtv needed. You drained and refilled from the same bottom plug?

 

[wcasey5]

Re: removing lower gear case to service water intake tube.

yep, same bottom plug. 2 quarts total, no air bubbles. No RTV?, what keeps it from leaking?

 

[Idlespeedonly]

Re: removing lower gear case to service water intake tube.

If you are draining and filling from the same plug you are doing it wrong.
The passage for the intermediate shaft in the only oil passage.
It will make sense when you get it apart. There are 2 big'ol fat orings you will need to replace also. There is nothing special about them. A good industrial supply house should have them.

 

[wcasey5]

Re: removing lower gear case to service water intake tube.

AH HA! That makes sense! Thanks!

***** warning, the paragraph that follows is the result of false memory syndrome, possibly dementia ***

So from what I understand, and not to start an argument or anything, you drain and fill from the bottom hole. What I did was remove the dip stick, remove the bottom plug and let it drain, got approximately 2 quarts out. Remove the center plug. Attach the oil pump thing to the bottom hole and fill until it comes out the center plug. Put the center plug in, then continue to fill until it registers on the dip stick. Replace the dip stick, remove the oil pump from the bottom hole (it won't leak much because there is no way for air to get in if it is sealed well, but you have to be fast) and replace the plug. Then top off through the dip stick (very little oil, a few ml at most). I took out 2 quarts and replaced 2 quarts, and that is the stated capacity. Ran well all last year. Did I do it wrong? Thanks.

 

[Idlespeedonly]

Re: removing lower gear case to service water intake tube.

Maybe you have been lucky, I dont know.:noidea:

But have a look here, for the procedure. But the center plug is where it is filled from.http://forums.iboats.com/omc-i-o-inboard-engines-outdrives/omc-cobra-fill-327253.html

 

[bruceb58]

Re: removing lower gear case to service water intake tube.

yep, same bottom plug. 2 quarts total, no air bubbles. No RTV?, what keeps it from leaking?

I am amazed you are doing it this way since you said this one year ago:

If you pumped all the oil from the bottom plug, then that is the incorrect procedure. You need to fill from the middle plug. You may have a huge air bubble, how much oil did you use?

The instructions to do it properly are in here:
http://forums.iboats.com/mercruiser-i-o-inboard-engines-outdrives/omc-information-334348.html

 

[wcasey5]

Re: removing lower gear case to service water intake tube.

oops, it was a year ago and I admit I didn't look up the procedure lately. I probably filled it from the middle hole *embarrassed* and just had a brain fart. Good thing the people on this board are sharp, really sharp, which is why I always consult the board before a procedure. Thanks again!

 

[Lou C]

Re: removing lower gear case to service water intake tube.

View attachment OMC shift rod adjustment 1.bmp




If its been used in salt water it can be difficult to separate the lower from the upper. First you have to make sure all the bolts have been removed including the trim tab (mark its location first). You can pry between the housings carefully or do what I had to do to get it apart, use bolts in the lower mounting holes on the upper unit and a piece of all thread through the trim ram rod hole. Then I put a scissor jack under the 2 bolts and one under each side of the trim ram rod (all thread). Cranked each jack a little at a time and it popped free. Salt deposits build up under one of the orings (by the water passage cover) and made it impossible to remove by prying, etc. I do this about every other season to clean out the water intake area and it ensures that it will come apart when work has to be done. I coat all the bolts with OMC gasket sealer which seals out salt corrosion. OMC triple guard grease on the o-rings. When re-assembling, put the one water tube grommet in the lower unit water passage tube hole and then put the guide into it. Then put the other grommet in the upper gear housing and put the water tube into that grommet. When you lower the upper on to the lower, the guide will help the tube center itself.

 

[Idlespeedonly]

Re: removing lower gear case to service water intake tube.

Dang Bruce, quite the detective.:laugh:

 

[bruceb58]

Re: removing lower gear case to service water intake tube.

Dang Bruce, quite the detective.:laugh:

My memory sucks but believe it or not, I remember this thread.

 

[Idlespeedonly]

Re: removing lower gear case to service water intake tube.

My memory sucks but believe it or not, I remember this thread.

I understand completely. There is one thread on here I will never forget. And I bet you know which one i'm talking about.:facepalm:

 

[wcasey5]

Re: removing lower gear case to service water intake tube.

My memory sucks but believe it or not, I remember this thread.

Not as bad as mine! I remembered wrong and convinced myself that I did it that way :facepalm: :lol: Thanks again for all the advice, it's great.

 

[Idlespeedonly]

Re: removing lower gear case to service water intake tube.

Thats nothing. I have a Ford Ranger in the shop that has a knock. It sounded like it was from the upper front area. Thought it was the timing chain guide broke. Nope they look perfect. But nothing was real wet with oil. I called the owner and asked him when the last time he checked the oil was. He said when he first heard the knock, he checked it and it looked good. He came over, we pulled the plug and watched about 3/4 of a quart trickle out. I think he checked the transmission fluid. We looked at the idiot lights, he does have a low oil light But it was covered by a business card on the cluster.

 

[bruceb58]

Re: removing lower gear case to service water intake tube.

I understand completely. There is one thread on here I will never forget. And I bet you know which one i'm talking about.:facepalm:

Let me guess...had something to do with manifolds?

 

[Idlespeedonly]

Re: removing lower gear case to service water intake tube.

Yep. I still laugh at that one.

 

[PARTRIDGE MAN]

Re: removing lower gear case to service water intake tube.

HI Wcasey5,this is my first post,i am the new kid on the block you can find a good two part video on u tube by Wayne Coll -how to remove lower unit on omc cobra. Lorne

 

[wcasey5]

Re: removing lower gear case to service water intake tube.

Thanks, I actually watched that video before posting. It is very well detailed but I still couldn't figure out what sealed the oil in, but now that I know about the O rings, it is pretty obvious in the video. He did a very good job of describing the process in both parts. Thanks again, and welcome aboard!