Mercruiser 165 milky oil problem. Bellows?

[auscarter12]

I recently purchased an early 70s model boat with a Mercruiser 165 with an early Mercruiser outdrive (Series 1 I believe). I had some work done on the outdrive and had the gear lube changed and the upper unit resealed because of a previous leak. I did not have the lower unit resealed because of the cost of labor, so I decided to take my chances and just reseal the upper unit. Unfortunately, that meant there was no warranty on the upper unit because of the liability caused by not sealing the lower unit. Anyways, I took it out for the first time the other day and checked the gear oil afterward and it was milky white, which obviously means water is getting into the outdrive. I don't know much about the bellows for this outdrive. I know there is a small bellow for the shift cable, then 2 big bellows (one on top of the other). The top bellow houses the U-joint and input shaft, I believe. What does the lower bellow contain? I disconnected it and it is hollow and had some water in it, but I am not sure if it is supposed to have water in it or not.

I am going to do a pressure test of the outdrive tomorrow. I don't currently have the funds to reseal the entire outdrive/purchase a new outdrive. Since gear oil is so cheap, I am considering just changing the gear oil out after every use. I know the leak limits the life of the outdrive, but oil is oil, and as long as it is fresh, would it be a huge issue as long as it was closely monitored? I am not sure of the repercussions of having a leaking outdrive with milky oil. Has anyone ever resealed their own outdrive themselves? Any help? Thanks!

 

[Grub54891]

I certainty would not run it that way. The cost of the unit is not worth it compared to the cost of a re seal. The most common place for a leak is the shift shaft seal,or the prop shaft from fishing line cutting the seal. The lower bellow is just the exhaust bellow,it channels the exhaust down through the prop,it is supposed to have water in it. The damage to the gears from moisture in there will kill the lower unit in a short time,them gears like good oil,there is a lot of stress on them parts.

 

[Bondo]

I certainty would not run it that way.

Ayuh,.... Ditto,.... Runnin' a leakin' drive is trouble waitin' to happen,.....

It'll be a possibly cheap fix now, or a drive replacement later,....

 

[auscarter12]

I am going to take the boat out at least one more time after changing the gear oil and see how long it takes before the oil gets milky. I pressure tested the outdrive today and it will not hold pressure, although I still don't know where the leak is coming from. It is not coming from the vent or drain plugs. The labor for resealing the outdrive is what is killing me financially - the parts aren't very expensive. Is it possible to be done by myself? I am pretty mechanically inclined, but have never resealed an outdrive before.

 

[Grub54891]

It's pointless to test it again. You already know it leak's. The upper is already sealed,time to drop the unit and figure out witch seal is leaking. You can re seal it yourself,if you have the tool to get the propshaft carrier out. The lowers are easy to seal up. As I said before,the shift shaft seal is an easy fix.

 

[auscarter12]

No Title

I think I found the source of the leak, or at least one source. Here is a picture. Is this the shift shaft seal? This is with the boat in neutral. I replaced the gear oil with new (blue) gear oil to see if I could find the source of the leak and I think I may have found it, at least one of them. On the left side of the shaft you can see some blue oil seepage and a little bit of water. How easy/complicated is this to fix? And what exactly is needed to replace this? Any special tools? Removal of the lower unit? Anything will help, thanks.

 

[Grub54891]

The shift shaft seal is on the lower half of the drive. You split the halves as if you were changing the impeller. The brass shift lever you see in the photo sits on it.
Why there is oil coming out from above is a mystery, you said the upper was sealed, and there shouldn't be oil there to begin with.

 

[auscarter12]

I'm not sure why there is oil coming from the top either. Unless the guys who sealed my upper unit didn't do a good job. Obviously they didn't because there is all sorts of oil in my u-joint bellow, meaning that input shaft seal has to be leaking, correct? I'm taking the boat back to the guys that did the work and and going to see what we can figure out.

 

[Grub54891]

Yup,There should not be oil in the bellow. you could have the driveshaft seal leaking also. That might explain the oil you are seeing,but at this point I'm not sure.