Mercruiser 165 Outdrive Gear Lube in Exaust

[yjanray]

So I was working on changing the impeller on my 165 outdrive MC-1 (boat and engine in my signature), and had issues getting the zinc anode off, then issues getting the propeller off, issue after issue.

Anyway, I finally got the propeller off, and drained the gear lube. I have water in the lube, but once I got the prop off, i noticed a pool of nice fresh high performance "green" gear lube in the bottom of where the through prop exhaust water would run. It is kinda hard to explain where it is, but I am planning on splitting the drive, replacing the water pump assembly and seals in there. Just trying to get an idea what would cause this before I get the thing apart. Below is a picture of what i am talking about.

Thanks
Yorke

 

[Don S]

Re: Mercruiser 165 Outdrive Gear Lube in Exaust

Drain the drive and pressure check it to 15 psi. Use some soapy water in a spray bottle and spay the inside of the drive around the seals and watch for bubbles. Could also be under the raw water pump.
I have often had to remove the upper from the lower and pressure check each section separately to find the leak.

 

[yjanray]

Re: Mercruiser 165 Outdrive Gear Lube in Exaust

Ok. I was going to split the drive tonight and check out the water pump issue and the seals there. How do you hold pressure with the two pieces split?

 

[Don S]

Re: Mercruiser 165 Outdrive Gear Lube in Exaust

Plug the small hole between the upper and lower. I have a set of small rubber plugs of various sizes that work perfect for the job. Or have a friend hold their finger over it.

 

[yjanray]

Re: Mercruiser 165 Outdrive Gear Lube in Exaust

Ok cool, Thanks. I am going to try and get the two halves split today, and see what I have in there.

 

[yjanray]

Re: Mercruiser 165 Outdrive Gear Lube in Exaust

Alright, well I first started this project keeping the upper on the boat, but then quickly realized that was stupid when I went to put the lower back on, and I couldn't get it on, at all.

So, i took the upper off (first time ever doing that for me) and boy, did I find a MESS! Just watery grease that stunk like mold, all up in the bellows and everywhere. must drained a pint of water and oil outta there.

I had a mechanic install new u-joints on the boat, about two years ago, and I am not sure what happened, but he might have hosed me. Below are some pictures of what I'm dealing with.
So do these u joints look new? there only 2 years old, and last year we only put about 10 hours on the boat


Heres the mess that I'm dealing with. Is there anything, seal wise that I need to change in here. The gimball bearing back there seems to move freely with no grinding or anything like that.



Here is the picture of the new seals that I need

Same, different angle



And finally, here is where I found the leak when I pressure tested the upper unit. It is the seal that goes into the gear housing area on the upper.




Outdrive Serial No: 5390295

 

[yjanray]

Re: Mercruiser 165 Outdrive Gear Lube in Exaust

I had to make another post, i ran out of picture attachments. Two more things, one, what size is the bolt that holds the top of the outdrive on, you know where the eyelet hook attachment is on a MC-1...pic below.



Also, Not sure what to make of the shift shaft cable, when I pulled the outdrive off, it looked broken. Do you guys think its broken at all, like on the end?




Thanks for the help

YOrke

 

[yjanray]

Re: Mercruiser 165 Outdrive Gear Lube in Exaust

Drain the drive and pressure check it to 15 psi. Use some soapy water in a spray bottle and spay the inside of the drive around the seals and watch for bubbles. Could also be under the raw water pump.
I have often had to remove the upper from the lower and pressure check each section separately to find the leak.

Maybe my responses weren't very clear, I kinda just rumbled. I pressure checked the upper unit and lower unit, off of the boat. The lower unit held pressure with no issues, no leaks detected. However, Once I started applying pressure to the upper unit, i could hear escaping from the seal around the U-Joints.

could a leak there cause water in the outdrive? When i took the upper off the boat, there was a lot of water and oil mixture in the bellows and it was just a mess inside the ujoint bellows. Also, I am pretty sure that the oil seal where the lower unit drive shaft joins the upper unit was bad. Would that seal cause water intrusion into the outdrive?

Thanks

 

[ktbarrentine]

Re: Mercruiser 165 Outdrive Gear Lube in Exaust

From the sounds of it, you have at least two problems in the upper area. 1. the drive bellows has a leak (or possibly a leak in the O- ring joint where the drive meets the bell housing), letting water in. Inspect your drive bellows very closely. How long has it been since it was replaced?

2. The yoke seal is leaking, letting the water in the bellows get into the drive, and letting the drive oil get into the bellows, creating the mess you saw.

The seal you refer to where the lower unit drive shaft joins the upper unit is one of two seals in that area. The lower of the two (I believe that is the one you are referring to) is there to help keep exhaust/water from getting into the splines of that shaft where it joins the upper. There is another seal above that to keep oil from the upper unit from escaping, and if the lower seal is failed as you believe (and looks to be somewhat common for that era drive), helps keep the water from getting up into the upper part of the drive. Hope that makes sense. It shows up well when you look at the exploded view of your drive. Was there an O-ring on the vertical drive shaft below the spline area? That O-ring is known to cause problems with that lower seal in the upper drive, causing it to not seal properly and letting water into the spline area. Advice is to leave the O-ring off during rebuild...it is not needed. That lower seal is easily replaceable, by the way, while your drive is split apart. There are several threads (one very recent) in this forum on that subject. IF... the upper seal in that area is also bad, then that might explain the gear oil you saw behind the prop. BUT... you would have seen/heard an air leak there during your pressure test of the upper. Did you hear/see (soap bubble check) any leaks there?

 

[yjanray]

Re: Mercruiser 165 Outdrive Gear Lube in Exaust

From the sounds of it, you have at least two problems in the upper area. 1. the drive bellows has a leak (or possibly a leak in the O- ring joint where the drive meets the bell housing), letting water in. Inspect your drive bellows very closely. How long has it been since it was replaced?

2. The yoke seal is leaking, letting the water in the bellows get into the drive, and letting the drive oil get into the bellows, creating the mess you saw.

The seal you refer to where the lower unit drive shaft joins the upper unit is one of two seals in that area. The lower of the two (I believe that is the one you are referring to) is there to help keep exhaust/water from getting into the splines of that shaft where it joins the upper. There is another seal above that to keep oil from the upper unit from escaping, and if the lower seal is failed as you believe (and looks to be somewhat common for that era drive), helps keep the water from getting up into the upper part of the drive. Hope that makes sense. It shows up well when you look at the exploded view of your drive. Was there an O-ring on the vertical drive shaft below the spline area? That O-ring is known to cause problems with that lower seal in the upper drive, causing it to not seal properly and letting water into the spline area. Advice is to leave the O-ring off during rebuild...it is not needed. That lower seal is easily replaceable, by the way, while your drive is split apart. There are several threads (one very recent) in this forum on that subject. IF... the upper seal in that area is also bad, then that might explain the gear oil you saw behind the prop. BUT... you would have seen/heard an air leak there during your pressure test of the upper. Did you hear/see (soap bubble check) any leaks there?

Thanks for the response. As far as the bellows go, they were replaced two years ago, when the U-joints were replaced. They are in good condition and are not brittle. Whenever I store the boat, I store it with the out-drive down, as to keep pressure off the bellows. The O-ring you mention, where the drive meets bell housing, is that the bell housing gasket that goes around the entire bell housing?

" IF... the upper seal in that area is also bad, then that might explain the gear oil you saw behind the prop. BUT... you would have seen/heard an air leak there during your pressure test of the upper. Did you hear/see (soap bubble check) any leaks there? I am not sure how to inspect or get soapy water on the upper seal you are talking about. Isn't that area behind where the u-joints go into the housing? Wouldn't I have to take those off the upper to get to that seal?

So from what I can understand, water can be entering the out drive either by 1) water in bellows, which is entering leaky yoke seal, or 2) exaust water is getting into the out drive through the leaky seal where the lower and upper splines meet?

 

[ktbarrentine]

Re: Mercruiser 165 Outdrive Gear Lube in Exaust

I am not sure how to inspect or get soapy water on the upper seal you are talking about. Isn't that area behind where the u-joints go into the housing? Wouldn't I have to take those off the upper to get to that seal?

So from what I can understand, water can be entering the out drive either by 1) water in bellows, which is entering leaky yoke seal, or 2) exaust water is getting into the out drive through the leaky seal where the lower and upper splines meet?

One of your photos shows the seal in question in the upper drive (where the vertical drive shaft penetrates into the upper drive). That seal is the lower of the two. The next one is above it (with the upper in correct orientation), or if you have the upper inverted, the second seal will be below the one in your picture (you should refer to the exploded view of your drive in the manual). This is the area you want to listen to / apply soap solution to when you do your pressure check of the upper (along with the other area...the yolk seal, which you say you already found to be leaking).

The O-ring seal that I was referring to between your upper unit and the bell housing, also sometimes referred to as the "nose" seal or o-ring, is a large O-ring with a square cross-section that you would find either on the castle nut of your upper (between the U-joints and the drive housing, or it will still be in the bell housing, where the bellows starts(from the looks of your photos, it looks like it is still in the bell housing and is in not-so-good shape. It needs to be removed, inspected and replaced). (again, look at the diagram in the manual). If your bellows is good as you say it is, then this is the most likely other source of water into your bellows.

 

[yjanray]

Re: Mercruiser 165 Outdrive Gear Lube in Exaust

One of your photos shows the seal in question in the upper drive (where the vertical drive shaft penetrates into the upper drive). That seal is the lower of the two. The next one is above it (with the upper in correct orientation), or if you have the upper inverted, the second seal will be below the one in your picture (you should refer to the exploded view of your drive in the manual). This is the area you want to listen to / apply soap solution to when you do your pressure check of the upper (along with the other area...the yolk seal, which you say you already found to be leaking).

The O-ring seal that I was referring to between your upper unit and the bell housing, also sometimes referred to as the "nose" seal or o-ring, is a large O-ring with a square cross-section that you would find either on the castle nut of your upper (between the U-joints and the drive housing, or it will still be in the bell housing, where the bellows starts(from the looks of your photos, it looks like it is still in the bell housing and is in not-so-good shape. It needs to be removed, inspected and replaced). (again, look at the diagram in the manual). If your bellows is good as you say it is, then this is the most likely other source of water into your bellows.

Is part 20 the seal you are talking about?


I think i found the o-ring you are talking about, which is part 9?

I am not sure how to even go about fixing the yoke seal. From reading some other threads on here and looking at the manual, you need a special tool to get it apart?

Thanks

 

[ktbarrentine]

Re: Mercruiser 165 Outdrive Gear Lube in Exaust

The picture of the first diagram is too small to see the numbers... But in any case, you need a diagram of the upper unit to see the seals associated with the spline area of the vertical shaft (where the lower unit shaft penetrates into and joins with the upper unit).

Yes... part 9 is the upper unit-to-bell housing O-ring. Did you take it out and see how it looks? It may give you a good clue as to whether the water was getting in from there or not.

 

[yjanray]

Re: Mercruiser 165 Outdrive Gear Lube in Exaust

The only diagram of the upper unit that I can find is this one.

It doesn't show the seals up there, but it seems that the lower unit one does.

On a seperate note, it does appear that the o-ring mentioned earlier, that seals the out drive to the bell housing was bad. I took it off, and it looks pretty torn up. I guess I am wondering, if my bellows arn't leaking, how else could water get into that area? The bell housing gasket was bad maybe?

Could exaust water passing by where the splines go into the upper unit cause water intrusion?

Thanks

EDIT: I cannot figure out why the diagrams show up so small, but if you save image on desktop, then you can zoom in on them and see the numbers. THanks

 

[MarkSee]

Re: Mercruiser 165 Outdrive Gear Lube in Exaust

Once I started applying pressure to the upper unit, i could hear escaping from the seal around the U-Joints.
could a leak there cause water in the outdrive? When i took the upper off the boat, there was a lot of water and oil mixture in the bellows and it was just a mess inside the ujoint bellows.

The seal around the u-joints and gear lube in the bellows is number 19/20 in your picture above. That's what failed on my bravo that allowed gear oil in the bellows but I had no water in there.

Chris (Achris) posted up a video on how to replace that seal last week but you'll need a special tool to get the retainer nut off.

You are right that the drive to bell housing o-ring has taken a beating.

Mark

 

[yjanray]

Re: Mercruiser 165 Outdrive Gear Lube in Exaust

I think I understand what parts I need for the bell housing.

Does this look like the correct part where the upper drive shaft mates with the upper unit?

Tapered Roller Bearing for Mercruiser, Mercury, Mariner 31-53079A1, GLM 21570 - Sierra 18-1164 - iboats

 

[yjanray]

Re: Mercruiser 165 Outdrive Gear Lube in Exaust

Well i replaced the upper and lower seal in the upper unit gear housing. It was not easy.

I finally got the bearing assembly apart from the u-joints, and seperated the oil carrier assembly that was leaking during my pressure test.

My question is, the seal doesn't look that bad of condition. Could the grooves in the picture cause it to leak? Either way, I ordered a new oil carrier assembly and will install it.

Any tricks to putting the bearing assembly back together correctly? If I didn't take the bearings apart, do I have to adjust any thing with the pre-load?

Couple more pictures of the bad seal

 

[Don S]

Re: Mercruiser 165 Outdrive Gear Lube in Exaust

You don't need the whole carrier, just the seal.
With the rust, it probably just wore the surface of the seal away. Might want to look at the sealing surface on the yoke as well. They usually get grooved or rust pitted and needs replaced as well.

 

[ktbarrentine]

Re: Mercruiser 165 Outdrive Gear Lube in Exaust

Make sure you closely inspect the yoke shaft where that seal rides, for any grooving. Let's see close-up some pics. If it is grooved, then there are ways to deal with that...but lets see what you've got. Your seal can look good, but still leak due to age, or wear-grooving discussed above. Anytime you replace a seal on a shaft, check the shaft closely. (Dang..typing at the same time as Don S again!)

Also... just curious...how did you get your castle nut off? There is a special tool for that, and a specific torque spec for re-install. Just sayin'.

 

[yjanray]

Re: Mercruiser 165 Outdrive Gear Lube in Exaust

You don't need the whole carrier, just the seal.
With the rust, it probably just wore the surface of the seal away. Might want to look at the sealing surface on the yoke as well. They usually get grooved or rust pitted and needs replaced as well.

I guess I don't know the difference between the carrier and the seal.. Either way, I ordered it at the local shop, and it'll be here on Monday. Here are some pictures of the yoke. The sealing surface on the yoke is very smooth, i don't feel any grooves or anything. It looks bad, but i swear, it does not feel grooved at all.....

Thanks