Mercruiser 3.0 won't "lock in"

[Scott06]

I noticed as well, but it didn't feel rough/pitted. I think it may just be some tarnish or even bacteria/mold from sitting with some moisture in it? I will try to get better pictures tonight and verify further.

you can see some staining from moisture especially on top bearing that is above the lube level these were taken out of my gen 2 never had any water show in the drive lube, but had sat for years before I got it (10 years old with only 37 hrs on it). Drive made no noises, got torn down because I picked up a fishing line on prop shaft and saw the staining

 

[alldodge]

Opinion
The drive had very little lube in it and gears don't look bad but don't look go either. The drive needs a complete tear down and I won't be surprised if a SEI drive is in the future

 

[tr@v1s]

Opinion
The drive had very little lube in it and gears don't look bad but don't look go either. The drive needs a complete tear down and I won't be surprised if a SEI drive is in the future

Why an SEI drive?

Edit: I guess I should ask what an SEI drive is as well? (Cautiously watching for my ignorance punishment to begin...)

 

[Kola16]

Why an SEI drive?

Edit: I guess I should ask what an SEI drive is as well? (Cautiously watching for my ignorance punishment to begin...)

SEI is a brand that sells more affordable aftermarket replacement drives that are still quality. OEM Mercruiser drives cost more or are no longer in production.

 

[tr@v1s]

you can see some staining from moisture especially on top bearing that is above the lube level these were taken out of my gen 2 never had any water show in the drive lube, but had sat for years before I got it (10 years old with only 37 hrs on it). Drive made no noises, got torn down because I picked up a fishing line on prop shaft and saw the staining

So, assuming I put oil in it tonight and it doesn't leak or has a VERY mild leak...would you feel safe running it for a few more weekends before winterizing the boat and then pull and rebuild over the winter?

 

[tr@v1s]

SEI is a brand that sells more affordable aftermarket replacement drives that are still quality. OEM Mercruiser drives cost more or are no longer in production.

Ahh..ok. on the bright side, if the other boat i bought proves to be shot as far as the hull goes, I have a full motor and drive in it that should basically be identical to this one and I only paid $500 for the whole setup. Outdrive on it feels really solid. Of course I won't know for sure until I test it and that's a ways out.

 

[tr@v1s]

Trying to figure out the pressure tester (fairly simply leak down check basically). Trying to find the thread pitch for the drain plug and didn't see it listed in the post shared earlier.

Went to the homemade tools section and the top 2 links for pressure testers are both not good. First one goes nowhere and second one goes to another unrelated post.

 

[Scott06]

So, assuming I put oil in it tonight and it doesn't leak or has a VERY mild leak...would you feel safe running it for a few more weekends before winterizing the boat and then pull and rebuild over the winter?

hard to say from the keyboard. I would do a pressure test first.

 

[Grub54891]

Pressure test and if it passes, you “might” be ok for a couple days of tooling around. No guarantees. If it gets worse and destroys the gears/drive, it’ll get more expensive from there. Unless you just get a new sei drive. I’ve personally seen some that destroy the case when things go south. I used to work at a shop that rebuilt drives for winter work, but haven’t for 17 years. Never had one come back with issues.

 

[Scott06]

Trying to figure out the pressure tester (fairly simply leak down check basically). Trying to find the thread pitch for the drain plug and didn't see it listed in the post shared earlier.

Went to the homemade tools section and the top 2 links for pressure testers are both not good. First one goes nowhere and second one goes to another unrelated post.

View attachment 411185

i think the thread is 3/8 -16" use the fitting off a gear lube pump, although it is hard to find one with a metal fitting vs plastic

here is one

Amazon.com: Lower Unit Gear Oil Pump for Standard Quart Bottles, Includes 3/8 inch Metal Swivel, 8mm and 10mm Adapters Fit Most Marine and Mercury Boat Outboard Motors (Not Compatible With Volvo Penta) : Automotive

Buy Lower Unit Gear Oil Pump for Standard Quart Bottles, Includes 3/8 inch Metal Swivel, 8mm and 10mm Adapters Fit Most Marine and Mercury Boat Outboard Motors (Not Compatible With Volvo Penta): Hand Fuel Pumps - Amazon.com ✓ FREE DELIVERY possible on eligible purchases

www.amazon.com

here is just the fittings

Amazon.com: MorningRo 6 Pcs Lower Unit Gear Oil Pump Adapters for Outboard Motor Includes 3/8 Inch Metal Swivel, 8mm and 10mm Adapters Fit for Most Boat Outboard Motors Standard Quart Bottles : Sports & Outdoors

Buy MorningRo 6 Pcs Lower Unit Gear Oil Pump Adapters for Outboard Motor Includes 3/8 Inch Metal Swivel, 8mm and 10mm Adapters Fit for Most Boat Outboard Motors Standard Quart Bottles: Outboard Motors - Amazon.com ✓ FREE DELIVERY possible on eligible purchases

www.amazon.com

 

[kd4pbs]

I do know that an OMC800 without lube will run behind a 260+ HP V8 for about 5 minutes at moderately high speed before locking up. I also know that if you then open the plug at the top of the drive while in the water to get something in there that will act as a coolant and lubrication will get you a few miles back to the dock at idle. I guess if I were Bondo, I'd have to write that any water is better than no oil. Or something like that. :\
If it were me, and that drive doesn't have chipped gear teeth and the bearings are not terrible, I'd just run it, as long as my life didn't depend on it.

 

[Bondo]

So, assuming I put oil in it tonight and it doesn't leak or has a VERY mild leak...would you feel safe running it for a few more weekends before winterizing the boat and then pull and rebuild over the winter?

Ayuh,..... If you want to do that, go for a ride, then check for water in the gear lube, before you consider going boating again,.....

 

[tr@v1s]

Well, good news is I made a makeshift pressure tester using my combo tire inflator/gage and the cheap hose and plastic fitting for filling lower unit. Even with the very suspect connections it held 15 pounds of pressure for 10 minutes.

Not sure why the previous owners only had it half full of oil.

I checked gears and bearings again and found no damage. So, I went ahead and filled her up with oil and greased gimbal bearing and pivot points and u-joints. Alignment tool comes tomorrow as well as exhaust gasket. So, hopefully, I will have the old girl back together and testing her out with muffs tomorrow or Friday.

Also got the exhaust shutter in and installed today.

 

[tr@v1s]

I do know that an OMC800 without lube will run behind a 260+ HP V8 for about 5 minutes at moderately high speed before locking up. I also know that if you then open the plug at the top of the drive while in the water to get something in there that will act as a coolant and lubrication will get you a few miles back to the dock at idle. I guess if I were Bondo, I'd have to write that any water is better than no oil. Or something like that. :\
If it were me, and that drive doesn't have chipped gear teeth and the bearings are not terrible, I'd just run it, as long as my life didn't depend on it.

Something tells me the details of this story are rather entertaining...lol

 

[Scott06]

Well, good news is I made a makeshift pressure tester using my combo tire inflator/gage and the cheap hose and plastic fitting for filling lower unit. Even with the very suspect connections it held 15 pounds of pressure for 10 minutes.

Not sure why the previous owners only had it half full of oil.

I checked gears and bearings again and found no damage. So, I went ahead and filled her up with oil and greased gimbal bearing and pivot points and u-joints. Alignment tool comes tomorrow as well as exhaust gasket. So, hopefully, I will have the old girl back together and testing her out with muffs tomorrow or Friday.

Also got the exhaust shutter in and installed today.

you should be good to go if it holds pressure and nothing was damaged running that low

 

[tr@v1s]

you should be good to go if it holds pressure and nothing was damaged running that low

I'm hoping so! I'm gonna follow the advice of @Bondo and run a little and recheck several times to make sure I'm not getting water in the gear box. The oil I drained wasn't milky, but it was fairly dirty and certainly hadn't been changed or checked probably in years.

This motor coupler has probably been a real blessing in disguise as it has forced me to look more into things than I did when I bought it. Finding the exhaust shutter issue causing me to make sure and replace the impeller and checking the outdrive gearbox has all shown me other issues that could have caused even bigger - more permanent - damage that I am hopefully now preventing. Plus, I'm learning the things I need to know about this thing if I'm gonna be a responsible owner and maintain it correctly.

Probably going to plan to do a rebuild of the lower this winter just because it doesn't feel as 'tight' when I lock it into gear as the other outdrive I have. Guessing poor maintenance over the years has led to some wear in there. I mean, it is like 36 years old. Have you all found it more cost-effective to go to an SEI drive or rebuild the Mercruiser drives?

 

[kd4pbs]

Something tells me the details of this story are rather entertaining...lol

I guess even a tragedy is considered entertainment...
It might go along with explaining why your drive was empty of lube.
I was married to a very emasculating, demeaning, bipolar, evil woman for 14 years. Somewhere around year #7, I was doing the end-of-season maintenance on the boat; winterizing, oil changes, etc. I had just finished draining the drive when it started up with one of it's emasculating, demeaning, bipolar, evil rants that I needed to get inside an hour ago and attend to whatever it was that was far more important than what I had already been doing... probably change my daughter's diaper, since this procedure was beneath her.
Anyway - I'm sure that led to a whole evening of suffering, after which I had totally forgotten that I never filled the drive with oil.
Fast forward to next spring, and that pretty much was that.
At least it has a happy ending... several years after our divorce, she died of ALS - probably one of the most evil, insidious, torturous, protracted deaths one can suffer through.
That's my story and I'm sticking to it.

 

[Scott06]

I'm hoping so! I'm gonna follow the advice of @Bondo and run a little and recheck several times to make sure I'm not getting water in the gear box. The oil I drained wasn't milky, but it was fairly dirty and certainly hadn't been changed or checked probably in years.

This motor coupler has probably been a real blessing in disguise as it has forced me to look more into things than I did when I bought it. Finding the exhaust shutter issue causing me to make sure and replace the impeller and checking the outdrive gearbox has all shown me other issues that could have caused even bigger - more permanent - damage that I am hopefully now preventing. Plus, I'm learning the things I need to know about this thing if I'm gonna be a responsible owner and maintain it correctly.

Probably going to plan to do a rebuild of the lower this winter just because it doesn't feel as 'tight' when I lock it into gear as the other outdrive I have. Guessing poor maintenance over the years has led to some wear in there. I mean, it is like 36 years old. Have you all found it more cost-effective to go to an SEI drive or rebuild the Mercruiser drives?

Many here speak highly of the SEI drive as one can bolt it on and go, plus it comes with a 3 year warranty. So for an older boat owned by a DIYer its a good fit.

I personally have never had a drive I maintained let go so I have never used one. you got the idea keep and eye on the lube level and water intrusion while using it in season. unless its moored in the water it takes 10 min to open the lower and upper plugs to confirm you are good to go.

The issue is if you need to tear the drive down you need some merc specific tools. Usually by the time you buy the tools or rebuild a OEM drive a SEI drive starts to make sense. ..

When I resealed my drive I bought the needed tools off ebay used for about half price. Even then not sure it makes total sense but I like to be self sufficient maintenance wise.

 

[Bondo]

Have you all found it more cost-effective to go to an SEI drive or rebuild the Mercruiser drives?

Ayuh,..... Just buying the proper tools to rebuild the Merc drive, costs more than buyin' the new SEI drive to replace it,.....

 

[alldodge]

Ayuh,..... Just buying the proper tools to rebuild the Merc drive, costs more than buyin' the new SEI drive to replace it,.....

Agree
I have a lot of tools but needed get special tools which cost more than $700 just to rebuild the lower Bravo 3.