Johnson 1961 RDS-23 Lower Unit Drain Plug

[badsoden]

I just bought a used boat with a RDS-23. I'm getting ready to take it out for the first time and read that I should change the gear oil in the lower unit. I read the SELOC manual which confused me. Where is the drain plug on the lower unit and where is the vent plug? I keep reading if I take out the wrong screw it will kill the motor so I don't want to do that. Help.

 

[tashasdaddy]

Re: Johnson 1961 RDS-23 Lower Unit Drain Plug

Changing lower unit oil

There are 2 straight slot screw on the starboard side of the lower unit. Top is vent plug, bottom, drain and fill plug. ( do not touch Phillips head screw).

Remove the bottom plug, put container under lower unit, now remove the vent plug, while the oil is draining, replace the seals on the plugs part # 311598, buy several of these, ( they are a one time use item)

Walmart and many places sell a little hand pump. To use to fill the unit, you insert the tube into the bottom hole, and pump till oil reaches the vent hole. Install the vent screw, then remove hose, install the drain-fill screw, clean up mess.

The screws can be hard to get out, do not mess up the head. You may need to employ an impact screw driver to break them loose.

 

[F_R]

Re: Johnson 1961 RDS-23 Lower Unit Drain Plug

Changing lower unit oil

There are 2 straight slot screw on the starboard side of the lower unit. Top is vent plug, bottom, drain and fill plug. ( do not touch Phillips head screw).

Remove the bottom plug, put container under lower unit, now remove the vent plug, while the oil is draining, replace the seals on the plugs part # 311598, buy several of these, ( they are a one time use item)

Walmart and many places sell a little hand pump. To use to fill the unit, you insert the tube into the bottom hole, and pump till oil reaches the vent hole. Install the vent screw, then remove hose, install the drain-fill screw, clean up mess.

The screws can be hard to get out, do not mess up the head. You may need to employ an impact screw driver to break them loose.

Hunker down and look at the bottom of the nose cone, forward of the skeg. I believe you will find the drain plug there.

 

[badsoden]

Re: Johnson 1961 RDS-23 Lower Unit Drain Plug

Thanks. Just want to make sure I don't screw this up. I took a few picutures of the lower unit. I only found one flat head screw on the thing. Let me know for sure which is the drain and which is the vent plug. On the starboard (left side ?) there are three screws all at the top of the lower unit.

On the port (right side ?) there are four phillips screws at the top and just below the thrid phillips screw is another screw with a phillips head. Is that the vent hole?

On the bottom there is a big flat head screw near the middle. Based on what was said in this thread I would guess this to be the drain plug. From what I understand I take out the drain plug and the vent plug and drain out all the grease, then pump the grease into the drain plug until it comes out the vent hole. Is that correct. I know this should be easy, but this is my first boat and don't want to screw up. Thanks for the help. If you want to see the picutres I took give me an email address and I will send them.

 

[Chinewalker]

Re: Johnson 1961 RDS-23 Lower Unit Drain Plug

Don't touch any phillips head screws. ONLY remove the slotted head screws. The vent screw will look identical to the slotted drain screw. As FR noted, the drain screw is on the very bottom of the gearcase bullet, forward of the skeg. The vent screw is the same style screw (slotted, about the size of a dime), located on the starboard side of the housing.

 

[lindy46]

Re: Johnson 1961 RDS-23 Lower Unit Drain Plug

"then pump the grease into the drain plug"

DON'T use grease - get marine gear oil (appx.90 weight) available at any Johnnyrude dealer or walmart.

 

[badsoden]

Re: Johnson 1961 RDS-23 Lower Unit Drain Plug

Thanks I have now found the plugs. Guess I am slow on starting to learn about boats and enginees.

 

[asdasc]

Re: Johnson 1961 RDS-23 Lower Unit Drain Plug

Actually, you are one of the smarter ones. You knew enough to ask questions and fully understand before pulling out the stupid phillips screw. That would have ruined your week!

 

[Uxboat]

Re: Johnson 1961 RDS-23 Lower Unit Drain Plug

I know this thread is months old but I just was given a good looking RDS-23 made in Peterbough serial number 322815,what is the worry about the philips screws ?Just hung the engine on a stand and checking it over first to go are all the vaccum lines,should pull the fuel pump too and hope you can still find a diaphram. Thanks Mike

 

[asdasc]

Re: Johnson 1961 RDS-23 Lower Unit Drain Plug

It's really not as dire a situation as we made it sound, but it is a total pain in the butt if you pull the phillips screw. It is actually the pivot shaft for the shift linkage going up to the yoke. If you pull it out, sometimes you can get it back in by laying the motor down and jiggling the shift lever while poking in the hole with a dental pick to get things lined up again.

If worse comes to worse, you need to pull apart the lower unit, which means you need new seals for the lower unit to avoid future problems.

Don't pull the phillips, unless you have to.

 

[Uxboat]

Re: Johnson 1961 RDS-23 Lower Unit Drain Plug

Thanks, just got a manual and think this old engine will be my winter project should give me time as the winters up here last about 7 months.....