Changing Oil

[65bigfish]

Hi,

I am trying to discover how to change the oil in the crankcase on my 75' Evinrude 9.9 10524C. I can't seem to find any info on it. Anyone know the procedure?

Cheers!

 

[HighTrim]

Re: Changing Oil

Your oil will be premixed with the fuel, did you mean lower unit oil by chance?

 

[Texasmark]

Re: Changing Oil

Should be a standard procedure. Works best with engine vertical. Crankcase has a drain plug on the bottom of the gearbox bulge (usually forward and at about 45 degrees from vert) and a vent on top which is usually just above the antivent plate on the side of the lower unit.....nice shiny SS screws with a straight slot.

Both can be removed simultaneously and allow the oil to drain out. Ideally, you go to your Johnny/rude dealer to purchase your gear oil and while there get new washers to seal under the two screws you removed.....always best to use new washers if possible.

I used to run OMC engines and back then the oil was honey colored with it's clarity. I don't know what color it is today. Reason being, is that you want to check for water intrusion and water makes oil yellow-milky. Merc uses a dark blue oil and it's easy to detect water. With the honey oil it is more difficult.

Tubes of oil are pointed and that is to allow you to snip the end and stick the tube into the lower hole. You squeeze and roll up the tube till oil comes out the vent hole....give it time for the bubbles to vent out.

Keep the tube in place with pressure on it (like you had) and with the other hand install the top screw and tighten.....this helps to form a vacuum to hold the oil in for the next step.

Then with the lower screw ready, pull the tube out and quickly install the screw and tighten. Don't tear anything up, but they should be nice and tight...to the point where the screwdriver wants to slip out of the slot in the screw.

You will loose a tad of oil in the filling process but that's normal. Just keep it to a minimum.

HTH

Mark

 

[HighTrim]

Re: Changing Oil

Listen to mark and get those gaskets like he said, that is the number 1 spot for water intusion into the lower unit. I myself prefer the jugs that I hook my pump up to. It has an adapter that screws into the drain hole, keeping loss to a minimum. I find it a bit easier than rolling the tubes up and trying to get it all out into the lower unit. good luck.

 

[SandMan*]

Re: Changing Oil

Losing that bit of oil while fumbling to put the drain screw back in is important, you're supposed to drain one fluid oz. (30cc) to allow for expansion.

Cheers, it's easy!

 

[Vic.S]

Re: Changing Oil

Losing that bit of oil while fumbling to put the drain screw back in is important, you're supposed to drain one fluid oz. (30cc) to allow for expansion.

It does not say anything about that in the manual. In fact it says, "the drain/fill screw can then be securely installed without oil loss".

It also says, "If the proper tube or filler type can is not available, install the drain/fill plug, slowly fill gearcase through the level hole, allowing trapped air to escape. Install plug".

I always fill my 6hp with a brass syringe through the level hole because firstly I have a suitable syringe, secondly I dont buy oil in the fancy squeezable bottles and thirdly I find it easier and less messy.

 

[SandMan*]

Re: Changing Oil

3. Fill gear housing with lubricant until excess starts to flow out of lubricant vent screw hole.
4. At this point, drain approximately one fluid ounce (30cc) from gear housing to allow for expansion of lubricant.

Motor specific maybe?

Mine is a Merc 45.

 

[Texasmark]

Re: Changing Oil

My manuals over the years only said to not let too much escape when plugging; gave no measurement.

On filling large lower units, I use the pump on the quart bottle, but for the little guys, the tube......course if I happened to have a quart with pump sitting on the shelf.....in she goes.

On expansion, I really doubt that there is much. The gearcase, being cooled by the ambient water temp, really doesn't have an opportunity to get hot where the oil would be forced to expand. Besides the screw is not at the very top of the chamber leaving an air space, and I like to ensure that I get oil wicked up the driveshaft to lube the upper bearing.

Buttttt to each his own. Whatever works.

Mark

 

[65bigfish]

Re: Changing Oil

Thanks Guys, for all the input. I did not know that crankcase was lubricated solely by the fuel oil mix. I thought there would be some sort of crankcase fluid, but thats what I get for being a 4 stroke type of guy. I always had 4 stroke air cooled engines before this except for weed - eaters.

I will check the lower end unit fluid before the big trip. It has been changed about 15 hours ago.

Cheers!

Kris

 

[Texasmark]

Re: Changing Oil

Are we getting tangled up here? Lower unit has nothing to do with engine type. Maybe I misread the last reply.

2 cycle engines bring in the fuel air mix directly into the reed valves (like little metallic feeler gauges) where it lubricates the crankshaft and then is sucked into the cylinders where it lubes them in the combustion process.

2 cycle engines have ball, needle, and roller bearings on the loaded surfaces (crank , connecting rods, etc.) which take a very small amount of lubricant to function as compared to "bushing type" babbit bearing of a 4 cycle.

The lower unit consists of conventional ball bearings, all of which (except the upper drive shaft bearing) are completely submerged in oil as are the drive and shift gearing. The upper driveshaft bearing gets wick lubricated by the turning driveshaft.

Mark