Lower unit/water

noah4009

Petty Officer 1st Class
Joined
Nov 6, 2008
Messages
283
I have a 1971 Chrysler 55HP Outboard. Was last running 2-3 years ago. When I got it, it was not running. Thru the help of you guys I got it running but no water circulating. I ran it about 20-30 seconds and shut it down. Will still start ands run. I ordered the impeller and a LU gasket cause I saw build up oil in front of prop under LU Gasket. I just removed the screw to drain the LU oil and got about 1 cup of fluid. 75% water. I stopped there and did nothing else. I ordered a seal kit for the LU and new drain plugs and recession pin. (what they said you should never remove)
Question is: Am I wasting my time? I did not run it long, nor did I put it in gear. Do I need to order anything else for the apparent leak? I saw no metal particles on the drain plug. I also ordered the (2) drain plugs and the recession pin and washer. I noticed my pin looks like a regular screw with a round head. While the drain plug is flat and flush. Could this be someone just removeing and putting a regular screw in it?
 

Frank Acampora

Supreme Mariner
Joined
Jan 19, 2007
Messages
12,004
Re: Lower unit/water

You would need to run the engine until the paint started to smell or smoke to do damage to the engine itself.

Since the pinion is always meshed with both gears, I doesn't matter whether you had it in neutral or in gear. However, with no load on the gears, it would be difficult to damage them unless damage had already started.

Typically, if water gets into the lower unit, the oil has corrosion inhibitors which bind free oxygen. Free oxygen would be what causes rust on the steel internals. Again, TYPICALLY if the lower unit is not open to the air, the gears and shaft will not rust.

Since you did drain the oil and since you are going to re-seal the lower unit anyway, NOW is the time to disassemble and clean the internals. Then, a light coating of oil to protect until you can re-assemble everything.

Disassembling now will also let you know if you have damaged components which need replacement. Look specifically at the drive dogs on the clutch and forward gear. If the drive dogs are well rounded on the leading edges, they should be dressed square otherwise they will tend to pop out of gear.

Pick up a Clymers manual. It has some good drawings of the lower units, although yours will be listed as 20-50 HP
 

noah4009

Petty Officer 1st Class
Joined
Nov 6, 2008
Messages
283
Re: Lower unit/water

Disassembling now will also let you know if you have damaged components which need replacement. Look specifically at the drive dogs on the clutch and forward gear. If the drive dogs are well rounded on the leading edges, they should be dressed square otherwise they will tend to pop out of gear.

Pick up a Clymers manual. It has some good drawings of the lower units, although yours will be listed as 20-50 HP

Hi Frank
I have the service, parts and wiring manual for Chrysler. It has diagrams of everything. Do I still need to order Clymers? Taking apart the lower unit completely. Sounds very very difficult. You said look Specifically at the drive dogs on the clutch and forward gear. Where is that located? Any help is greatly appreciated.
 
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