Little hole on starboard side of LU

[noah4009]

I have a 1971 55HP Chrysler. On the LU, statboard side, just above most bottom section that holds prop is a little hole. What is it's purpose. I have heard for exhaust oil overflow. I want to know. I resealed my LU 3 months ago. I just replaced the bearing cage and filled with LU oil. The small hole on my LU has oil water mix coming from it. It is grey and bubbly oil with water.

 

[Frank Acampora]

Re: Little hole on starboard side of LU

I have a 1971 55HP Chrysler. On the LU, statboard side, just above most bottom section that holds prop is a little hole. What is it's purpose. I have heard for exhaust oil overflow. I want to know. I resealed my LU 3 months ago. I just replaced the bearing cage and filled with LU oil. The small hole on my LU has oil water mix coming from it. It is grey and bubbly oil with water.

The front of that lower unit where the shift linkage goes down is a blind cavity. That small weep hole drains water that would normally sit in the cavity and corrode the metal. Since the whole lower unit is exposed to exhaust gases, it is normal for a bit of engine oil to collect there and drain from the weep hole. Any oil mixed with water will appear milky. If the shift rod seal is new or OK, then it is probably sealing and the oil is probably not from your lower unit. Smell it! Engine oil smells way different than lower unit oil.

 

[noah4009]

Re: Little hole on starboard side of LU

The front of that lower unit where the shift linkage goes down is a blind cavity. That small weep hole drains water that would normally sit in the cavity and corrode the metal. Since the whole lower unit is exposed to exhaust gases, it is normal for a bit of engine oil to collect there and drain from the weep hole. Any oil mixed with water will appear milky. If the shift rod seal is new or OK, then it is probably sealing and the oil is probably not from your lower unit. Smell it! Engine oil smells way different than lower unit oil.

Frank
This is only happenning when engine is running. It is a steady flow. More so then I would think if the seal was leaking. I am thinking that the seal would practically have to be gone or totally shot for it to flow out at a steady flow as it is doing. Am I correct to think this.
Thanks

 

[Frank Acampora]

Re: Little hole on starboard side of LU

If it is a steady flow, and if it smells like lower unit oil, then I would suspect either the shift rod seal or the drive shaft seal.

The upper bearing is, I believe, a plain bushing. If it is worn and if there is any side play in the shaft, even a new seal will leak while running.

Of course, it also goes without saying that you need to check the lower unit oil itself for water contamination; if oil is getting out that way, it is because water is being forced in.