TOPIC: 1968 Mercury 1000 100HP lower unit.

Hello all,

I have another thread in the MFG owners area here:
www.fiberglassics.com/glassic-forums/home/mfg-owners-group/second-owner-of-a-68-chevron-2

The Merc 1000 seems to have some water mixing into the lower unit. The color of the oil after running it was white/grey. Also some fluid the same color runs out of the Flush screw that is above the Vent screw on the lower unit.

So i'm asking a question here that Ed already answered over there.

How long can I nurse it along in this condition, running in fresh water, before rebuilding the lower unit?

Also, how likely is someone to break the lower unit that has never worked on one before? I know there are a lot of variables to that question...

How long does a rebuild like that take? I don't have another motor to put on the boat and don't want to go all summer without her!

What can i expect to pay for a rebuild of the lower unit?

Thanks!

Dan

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I would replace the sealsyou cal pressure test it to find the leaky seal.(waterpump base) is an easy job. shift shaft seal is easy also. propshaft is more dificult to do. you can nurse it along by draining it and fill with grease. NOT MY CHOICE.if you do chech it after each and every day.JMHO

As Dave said you could get by with draining & refilling but good lower unit oil isn't cheap either. Shoot me an Email( This email address is being protected from spambots. You need JavaScript enabled to view it.) we might be able to work something out on a rebuilt unit.
Tim

I think what I'm gonna do is run it gently and change the gear lube every time and get another lower unit / spare outboard to put on while i rebuild the original lower unit.

You guys have me convinced, but i also need to be able to take the girls out on the water to justify the boat purchase!

But now will be the time to fix it before summer gets in full swing.

Tim, i'll send you an email.

Thanks!

I should have searched the forum a bit more. There are a lot of people who have posted the same thing!

Thanks for your patience...

first of all THAT motor is BEAUTIFUL.......so go to youtube and Im sure there are several movies of "how to" Im a mechanic and I think its an easy job, Ive done it at the ramp with no fancy tools at all, now that said if you have noise or metal shavings comming out, well then you need to rebuild. Ill bet you have fishing line between the propshaft seals.

Thanks ponyboy! I'll need to get some pics of her with her top of!

I changed the gear lube today and am going to post some pics. I was going to pull the prop and check the seal but my wife had other plans for my day.

I'm going to get a lower unit from Tim that is rebuilt already. Going up to silver lake for the meet to get it. Then when i swap those i'll rebuild the other one.

Eventually I'll have 2 full Mercs i can swap back and forth!

Here is a pic of the oil i drained today. That was run 2 or 3 times in the river.

Does that look milky?

Should this hole be there? It is in the top front of the lower unit. I can't see it in the SELOC manual and have not seen it on any other pictures.

Close up:

This one might show the problem.

Notice on the right side of fin under the prop there is a dark black line of oil. Probably shouldn't be leaking out of there i'd wager.

But wonder why it's darker than the oil draining from the drain hole.

Oh, is there any spray can paint i can use on her that will match?

OK, last one of the day i promise no more pics!

This Flush hole. What's it do?

Other than have water and gas come out of it...

On a previous post i thought their was oil coming out but when i smelled it today it is definitely gas!

Hi,
The hole on the gearcase leading edge is factory. During that time, Mercury added the hole with the thought that if silt was trying to fill the hollow area behind this hole, that the water forced into the hole (when the boat is moving) would flush the silt out.
The "FLUSH" screw can be removed, and an optional flushing attachment Mercury offered can be threaded-in to flush the cooling system with a garden hose (saltwater, or sand). By the way, Mercury did not recommend running the outboard with the use of this kind of flushing attachment. The flushing attachments which induce water (from your garden hose) into the gearcase water intake holes, is suitable for flushing and running (at slow throttle settings - as your garden hose cannot provide the amount of water seen when operating in the water) your outboard.
Your gear lube does not appear to be milky. To check for yourself, the captured gear lube will separate into gear lube and some water, if there is actually any water. It is typical to have unburned fuel and oil drain from the propeller area as you show. If you were losing gear lube, the color of the drainage would be the same color as the gear lube, as you are thinking.

Regards,
Joe
www.fergusonpoolemarine.com
This email address is being protected from spambots. You need JavaScript enabled to view it.

Hi Joe,

Wow! Thanks for all the info. I'll hold on to that lube and see if it separates.

I didn't expect one person to answer all the questions.

Thanks again,

Dan

And,...If you conclude that in fact it is your gear oil that is contaminated with water,...It is not the end!
There are (2) common causes that are easily remedied.
One is that the lower shift shaft has developed a rust ring that will no longer seal against the shift shaft bushing seal.
This issue can be resolved either by purchasing a new shift shaft from a late model inline-6 & shortening it to your needed length at the top end + replacement of the shift shaft's seal & o-ring
- OR -
By remachining the shift shaft bushing in a unique way so that the seal is inserted from the underside of the shift shaft bushing so that the seal runs against an undamaged part of the original shift shaft. (This does NOT work with every design of Merc's shift shaft bushings so be careful or ask for help in identifing specifically which one will work for you in this dilema).
ALSO,...Do not remove the lower shift shaft from the lower unit to replace or repair it without asking for detailed instructions or you will end up needing to totally dis-assemble your lower unit - commonly not a fun thing to do at best & can result in a real nightmare indeed!!
The other common problem is that the steel drive shaft gets rusty under the water pump's lower housing and consequently fails to seal the gear lube from the water in the water pump.
This can easily be resolved without further disassembly by carefully cleaning the rust from the driveshaft at the (2) different diameter seal areas, (I can explain how),...And then installing 'speedi-sleeves' of the appropriate dimensions to the two positions on the driveshaft where the (2) relative seals run.
I also put a thin coating of J&B Weld (2 part epoxy) on the driveshaft at the pitted area of the drive shaft that the new speedi-sleeves will run to insure there is no leakage under the new speedi-sleeves - then install the speedi-sleeves before the epoxy sets.
NAPA has the needed speedi-sleeves.
Once installed - replace the (2) seals & the o-ring on the water pump base unit & Tah-Dah,...No more water in the lube.
Doc F

Thanks Doc F!

I'm getting a spare lower unit from Tim at the meet in June. I'll run that one while i go over the original.

You could probably do everything you said above in an hour but it'll take me 3 months and i don't want my boat out of commission for that long!

I'm a recent owner of a 1969 V176 with a 1969 Mercury 1000. It's just coming off of the boat today for an overhaul in my garage. Mostly, to rebuild the carbs but I'm pretty sure the lower leg will need some love. I want to change the impellar and seals etc...I'm eager to see your resolution to your leg issues and to know another Merc 1000 owner.
Cheers!
Les

I've never rebuilt a lower unit, so I had Tim do one for me and picked it up at the Silver Lake meet in NY.

Just put it on last week and took it out for the first time yesterday. It's like driving a new boat!

Tim did an awesome job getting this together for me. Wish i would have had more time at his shop. He was tempting me with a 1250SS and a 150 HP...

It's always good to have a spare outboard, right?!

I have a bunch of pics of swapping out the lower unit I'll post when i get home tonight. Been too busy boating and working to keep up with the forum!

Good luck with your rebuild.

Here is what my impeller looked like:

Is the housing supposed to look like this?
It's hard to see but there is now a raised lip on one side of the circle.

Looks like i'll be buying a new one when i rebuild my original LU.

Here is a shot of the original LU after i removed it. Note how the water tube stayed in the LU.

the pump housing is shot it has been run dry.will always give a problem even with a new impeller. get a new pump kit including thr pump base.

Is the way that hole is worn any indication of another problem? Guess I'll find out when i tear apart the LU.

Thanks for the input!

not worn melted.from run dry.

How long would it take for that to happen? One time or repeated running out of the water without a hose?

Whenever i've run it out of the water i've attached my garden hose and only run it for a minute or so. So it must have been before i got it.

The impeller has 03 imprinted on it. Would that be the year of manufacture? Wonder if the last time he changed it was 10 years ago!

with the plastic housing about 20 seconds at 2000 rpm 30 seconds at idle.

So here is the thing. Last weekend after getting everyting back together and tested we put the boat in and it ran great!

Didn't do anyting to it this week.

Go to put it in this morning. Boat won't go in reverse!

Well it sort of does. When you go in Forward you feel a "bump" as it shifts into forward. It does it just as you get out of neutral.

When you shift into reverse it rattles, then when you get to where the throttle starts to advace it seems to shift into gear.

Messing with it in the garage it gives the same feeling. Click into gear about 2/3 the way down when it's supposed to start giving throttle.

So what do i need to look at?

PS: we did run it around the river for a while anyway. It was great! Who need reverse?

adjust your shift cable.

Great, i'll look up how to do that and give it a try.

Thanks!