Oil leak 2

[kat-a-tonik]

I recently resealed the lower unit on my FD-20C 1966 18hp Johnson, I did a pressure check and all seals were fine, so I put it on the water and everything was fine a couple of weeks later I went to take it out again and noticed gear oil seeping out of the small hole on the side of the lower unit shown in the second photo, I took it out on the water several more times and there was never any sign of water in the oil but oil keeps seeping from the hole, so I removed the lower unit and tore it down again, I blew air into the hole and sprayed soap on the inside of the lower unit and discovered that the oil is seeping out around the brass sleeve that the pinion gear sets in, how can this be fixed and is it worth fixing or should I try replacing the lower unit

 

[Vic.S]

Then it seems that it is leaking from where a retaining screw for the pinion bush should be fitted.

Unfortunately I cant find any such retaining screw shown on the parts diagrams.or even the bush for that matter. Just a (thrust) washer

Is the hole threaded? Any chance its not original? Any chance its not the original geacase but one from a different model

I'd be looking at plugging and sealing the hole, retaining the bush if necessary.

Did you replace the seal? if so have you fitted the new one correctly ? I take it no oil leaked from there before you resealed the unit.
(Probably wrong but I am thinking perhaps the hole is a water drain for the cavity below the water pump and that the seal should be below it but you have not pushed the seal in far enough so is above the hole )

 

[kat-a-tonik]

Vic.S, I don't see any were that there would be a retaining screw for the pinion bushing, I have found a diagram of the lower unit that shows the bushing as well as the washer, some one who works on boat motors told me today there is supposed to be a seal for the bushing but I don't see the seal in the diagram or a listing for it in the parts list.

The hole is not threaded and does appear to be original, and the gear case appears to be original as well.

The problem with plugging the hole is it may not let all the water drain from the leg of the motor and cause an even bigger problem.

When I ordered the seal kit there was not one for the pinion bushing just the ones for the drive shaft, shift shaft and prop, as well as the o ring for the gear head and the spaghetti seal.

 

[Vic.S]

Vic.S, I don't see any were that there would be a retaining screw for the pinion bushing, I have found a diagram of the lower unit that shows the bushing as well as the washer, some one who works on boat motors told me today there is supposed to be a seal for the bushing but I don't see the seal in the diagram or a listing for it in the parts list.

The hole is not threaded and does appear to be original, and the gear case appears to be original as well.

The problem with plugging the hole is it may not let all the water drain from the leg of the motor and cause an even bigger problem.

When I ordered the seal kit there was not one for the pinion bushing just the ones for the drive shaft, shift shaft and prop, as well as the o ring for the gear head and the spaghetti seal.

I am wondering if you have not pressed the drive shaft seal in fully. Its above "the hole" hence oil can leak from there. If it goes below the hole then it should then seal the gear case and open the hole up to the cavity below the water pump so that it will drain.

Maybe you'll look at it and say rubbish!

 

[racerone]

???????????-----I do not believe there is anything wrong here-----------The hole is simply a cavity drain to prevent freeze damage in cold climates.----There never was a screw used to hold any bushings in place either on these lower units !!!!!!--------No water in the lower unit then no problems !

 

[kat-a-tonik]

racerone, but what about the oil leak

 

[kat-a-tonik]

Vic, the drive shaft seal is driven down to were the top of the seal is flush with the housing

 

[racerone]

That oil is from the oil that is mixed with the gas !!!!!!--------Some goes straight through the engine and into the exhaust housing.--------Time to research the way these simple engines run !

 

[Vic.S]

Vic, the drive shaft seal is driven down to were the top of the seal is flush with the housing

Ok it seems then that raceron is right. Unburnt oil from the fuel not gear oil ,which you said it was in #1.

If no water is getting into the gearcase then you have no worries.

although "I blew air into the hole and sprayed soap on the inside of the lower unit and discovered that the oil is seeping out around the brass sleeve that the pinion gear sets in" is a little difficult to explain but perhaps I misunderstand what you are doing.