Mercruiser 140 I'm tearing in and have lots of ?'s

[Lavish]

Hi. I'm new here. I've been lurking through the forums for a while now since I bought my boat. I am now going to be tearing into the out drive to inspect for problems. Right now I'm trying to identify what I have to make sure I have all the correct information when I go to the parts store. I have a 1975 Mercruiser 140. What will I need for information. I have the serial number off the engine. Should there be any other numbers off the out drive or anything?

I only had the boat out once. It was working fine. I was able to rev it up good, and get to where I planed out, but then left off. When I went to do it again, as soon as it planed out, I heard a clunk, and started to loose speed it seemed. So I stopped. When trying to go again it made a knock noise. If I were to drive at idle no noise was being made, or VERY slight. Any throttle, and it would clunk, clunk, clunk. I assume this is my U-joints. I am going to remove the drive to inspect it in there.

I have some manuals, but again I am not sure if it is correct for what I have. I would like to identify that 1st. Second, I would like to know what else I should be doing/checking. I see I should be inspecting the bellows, and the gimball bearing. Can I replace the water pump in there at that time? I works, but if I'm already there..... This is the first boat I've ever worked on. I am pretty mechanical inclined from working on cars.

Any insight would be great. Thank you.

 

[Fishermark]

Re: Mercruiser 140 I'm tearing in and have lots of ?'s

Welcome aboard!

Removing the drive is a good first place to start looking. It certainly doesn't sound good.

You can go to the stickey post at the top of the page and download the appropriate manual for your engine and drive.

 

[Lavish]

Re: Mercruiser 140 I'm tearing in and have lots of ?'s

Thank you.

Ok, I just removed the drive. The u-joint assembly is very loose. So I am going to pick those up for sure. As I pulled it out water came out. And there is a puddle in my u-joint bellow. Nothing is rusted up in there, and it came right out smooth. So that's a good thing. Is the only way water there is from the bellows? If so should I replace them all? What else should I be checking/replacing, Thanks.

 

[Lavish]

Re: Mercruiser 140 I'm tearing in and have lots of ?'s

Also maybe the knocking noise isn't my u-joints. I don't know. Can anybody suggest what else it could be? I know I operated the the boat while the trim was in the trailering position. Bad I know, live and learn. I know the knock came from the drive unit. Any suggestions? Thanks.

 

[fishrdan]

Re: Mercruiser 140 I'm tearing in and have lots of ?'s

I'm with Mark, drain the gear lube and see what it looks like, milky, metal particles, looks like glitter in oil?. Then remove the drive and see what the Ujoints and gimble bearing look like. With a 75 (if you don't know the prior maintenance history) I would expect to replace the bellows and water pump at a bare minimum, just not inspect, but replace. Also check the engine alignment, you will need to buy the $50 tool.

Mercruiser Manual #4 should be the right one for your drive.

 

[Lavish]

Re: Mercruiser 140 I'm tearing in and have lots of ?'s

Thanks, I am going to buy the tool now. I can grab the gimble bearing and wiggle it a little? not normal I assume? When I spin it, it spins smooth, but it makes a noise. Replace I assume right?

Thanks on the manual!! I was looking at Number 2.

 

[fishrdan]

Re: Mercruiser 140 I'm tearing in and have lots of ?'s

Since you had water in the Ujoint bellows I would replace the gimble bearing and Ujoints. From what you are explaining, they need to be replaced. Bellows also...

Gimble bearing
Ujoints
Bellows kit
water pump kit

lower shift cable kit?
how do the coupler splines look? Pointy or squared off tops
engine alignment?
trim ram bushings?
hydraulic hoses?
etc.
etc.....

 

[Fishermark]

Re: Mercruiser 140 I'm tearing in and have lots of ?'s

Before you go out and buy u joints, make sure your drive is okay. You may luck out and simply have to replace the u joints... but if you end up needing a new drive, it will come with new u joints.

 

[Lavish]

Re: Mercruiser 140 I'm tearing in and have lots of ?'s

What do I check on my drive to make sure it's ok? I will read in the manual.

 

[zbnutcase]

Re: Mercruiser 140 I'm tearing in and have lots of ?'s

The clunk you hear could be the dog clutch in the lower slipping or the gears in the upper box comming apart

 

[Lavish]

Re: Mercruiser 140 I'm tearing in and have lots of ?'s

Ok so I'm just checking things. I am grabbing the shaft of my drive. THe shaft with the u-joints on it. I am spinning that. How smooth should that spin? Should there be any lash as I spin it back and forth?

I can hear the gears inside as I spin it by hand, and it'll make a small noise like hearing the gears going, as I go back and forth with it (spinning). And I get small movement before anything will start turning.


I don't know if the u joints are bad enough that they would have caused a clunk noise. Maybe I am looking at more problems? Is the drive something I can tackle myself? Tearing apart to see if it's bad?

 

[Lavish]

Re: Mercruiser 140 I'm tearing in and have lots of ?'s

Ok so I found a used out drive on Craigslist. I am going to go look at it. I figure either way it's good to have another. Hopefully it works. The guy said he bought a boat with a cracked engine block, that leaked water from improper witerization. So he took what he needed, and is selling the rest. he said he tried the boat in water before he bought it.

What should I look for when looking at it? I will check the oil in it for particles.
Can the upper and lower be separated for inspection? Or will nothing be revealed by separating them?

Thank you for the help so far! I also bought a new gimble bearing, and a bellow to replace. The bellow looks like a challenge to do. It has been intimidating to me, but I think I can tackle it.

 

[Lavish]

Re: Mercruiser 140 I'm tearing in and have lots of ?'s

So it was an out drive from a 165 merc, that was attached on his boat to a 140 merc. He said the only difference was the ratio. Can I run that on my 140 with no ill effects? Seeing his apart, I think I'm going to try to take mine apart some more to see if I see an obvious problem or not.

 

[Lavish]

Re: Mercruiser 140 I'm tearing in and have lots of ?'s

Ok so I separated my drive unit. When I did, where the driveshaft went up into the upper drive housing, milky oil came gushing out. this is the only place where I found milky oil. When I drained the gear oil out, it was all black. After I took off the lower unit, more oil came out of that too. I was able to inspect this oil, as when I first drained it, it went right into a used container. This oil has metal particles in it.

Why was the oil milky in only the one section?

Am I looking at total rebuild here? Or should I try to find the problem?

My drive shaft has marks on the gears, and a shiny spot on the shaft. I will get pics up after my camera battery charges up.

 

[fishrdan]

Re: Mercruiser 140 I'm tearing in and have lots of ?'s

It's not sounding good... Milky gear lube only from the upper and not the lower? I'd guess your Ujoint bellows was leaking and allowed water into the upper. I'd remove the upper unit's top cap (4 screws) and see how the upper gear set looks. Metallic looking gear lube only from the lower, or was the upper's lube metallic looking too?

The 165 drive won't work on your 140 (well, it would spin the prop) as the gear ratio is too far off and you won't be able to make that up with a different prop. A 165 lower unit would work with your 140 as the gear reduction is done in the upper unit

BTW, some of the seals are easy to replace, but working on the gears and bearings isn't done without a lot expensive tools and careful measurements. If your upper or lower is trashed it's best to go shopping for a different unit, a complete SEI drive (upper and lower units) is about $1200 with a 3yr warranty. Buying a used upper or lower is a gamble, but less expensive.

But, before you go shopping for a different drive, inspect what you have. My 73 drive (completely rebuilt 10 years ago) has a bit of fine metallic residue in it from time to time, but it still works fine.

 

[Lavish]

Re: Mercruiser 140 I'm tearing in and have lots of ?'s

Thank you. I'm glad you told me that. I was going to buy that that 165 drive today. He had it on a 140 engine, so I assumed it would have worked fine.

I think I am going to go the easy way out and just buy a new SEI unit. Thanks for showing me that! I figure I might as well not wast my time buying more used junk that I would just have to sink money into. Everything else on the boat works good, and the engine ran well. I think it will be worth it, and best of all, get me back on the lake!

Can someone point me at which one I will need?

http://www.sterndrive.cc/mm5/merchant.mvc?

I do have a new gimble bearing, and a new u-joint bellow I will need to replace.

 

[Fishermark]

Re: Mercruiser 140 I'm tearing in and have lots of ?'s

You want the SE106 - and you can buy them here on Iboats.

They are great units - I've installed a couple of them.

 

[fishrdan]

Re: Mercruiser 140 I'm tearing in and have lots of ?'s

He had it on a 140 engine, so I assumed it would have worked fine.

There is a snow balls chance in.... the 165 drive will work with your 140. IF the gears were replaced with a set of 2.0 (140HP, 3.0L) gears. Maybe the old owner used a 165 case? It's a real long shot, but you could check the 165 drive easy enough. Mark the Ujoint shaft and prop shaft, lock the drive into gear, turn the Ujoint shaft 2 complete revolutions and see if the prop shaft makes 1 complete turn. If the prop shaft makes more than 1 turn (like 1 1/4 turns) it's has the gears for a 165HP. The 165HP gear ratio is something like 1.65:1, not 2.0:1 for the 140HP.

I really doubt this is the case, but if the guy only wants a couple hundred for the drive....

 

[Lavish]

Re: Mercruiser 140 I'm tearing in and have lots of ?'s

Hey maybe that is the case. How would I go about locking the case into gear to do that check?

 

[Lavish]

Re: Mercruiser 140 I'm tearing in and have lots of ?'s

Well I have my brand spanking new SEI SE106 Outdrive on the boat!! I replaced my gimbal bearing, and my U-joint Bellow as well. I will give it a try tomorrow to see if I'm a Mercruiser mechanic or not! I have my fingers crossed. I would just hate the knocking noise be something else. Hopefully my post tomorrow is a cheerful one! Thanks for all the help thus far.