Home › Forum › Ask A Member › Johnson HD20 Drive Shaft Question › Re: Johnson HD20 Drive Shaft Question
I always apply grease to the entire driveshaft. The top end gets a little extra for the splined connection to the bottom of the crankshaft. The bottom end is important to grease to minimize friction where it passes through the upper gearcase seal. The rest of the driveshaft gets greased for corrosion protection.
I believe the small access hole in the driveshaft tube is the driveshaft tube vent, not a grease/oil fill. If I recall correctly, it looks like a brass hex nut with a hole in the middle on the outside of the motor on the Port side of the mid section. I own a couple of the HD-25’s, and they take 90WT. I’m not 100% sure about the HD-20, but if it doesn’t leak with the 90WT, then your probably OK.
If you look closely at your gearcase, there should be two screws/openings for hypoid oil. Both the fill and the vent are on the Port side with the small vent screw actually above the gearcase in the mid-section. Filling is done through the bottom hole and the top hole is a vent to let air out so the oil can displace it. The idea is to avoid trapped air pockets while filling.
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