Bicycle Mechanics - Beater hub advice

Call me cheap, or thrifty but I'm trying to keep a rather dubious old mountain bike on the road as my winter beater. After I adjust the cones on the rear hub, the left side keeps coming loose. I crank the cone and locknut together and tighten up the axle nut, ride a couple of miles, and the wheel is rocking. Maybe it's a washer problem. There's the cone, the locknut, the axle nut that has a flange on it, and an extra washer. Does that extra washer go inside or outside of the drops? See sketch. Any other usggestions? Thanks

Heere's the sketch.

That's a more common problem than you might think. The solution is to replace the axle. I think that the axle threads wear right at the place where the cone and locknut tighten against each other and won't hold the assembly tightly enough.

That's a more common problem than you might think. The solution is to replace the axle. I think that the axle threads wear right at the place where the cone and locknut tighten against each other and won't hold the assembly tightly enough.Thanks. There's a lot of axle showing at one end...maybe I'll try shifting everything over a half inch or switching the axle end-for end first.

I swapped the axle end for end. It's holding now. What with the extra axle length and the spacer between the cone and locknut on the right, I guess I'm now using parts of the axle thread that are in better shape.

Just as an aside, I cleaned and relubed one side of the hub, but I couldn't really get at the other side since I broke my pipe wrench trying to get the freaking freewheel off. Last time (6 months ago) the pipe wrench worked, after I bent the jaws of my bench vise trying to remove the freewheel. It's incredible that that tiny, ultralight, thin walled freewheel tool is stronger than my former pipe wrench and my former bench vice!