How much of the knuckle do I paint

[LTjackMB41]

All - I have a 1941 Willy's MB slate grill that I finally started restoring. I am working the front axil and in process of reassembling. I realize the knuckle should be bare metal, but my question is how much of it? It seems that not all of it needs to bare metal. How did it come from the factory? And given it is bare, does it require periodic maintenance (i.e. covering in oil or grease) to keep it from rusting?

[bmorgil]

A good question LT. The Knuckle Bell Seal wipes directly on the surface of the "Bell" on the axle tube. It doesn't rub to about 1" or so from where it is welded to the tube towards the tire. So if you painted about the first inch of it, it would stay out of the seal. No matter what if you only paint where it wont rub, it will rust on the bell if the wheels aren't "swept" from side to side once and a while. When you sweep the wheels back and forth, it will lube the bare spots and they wont rust. If you are rebuilding it, and you clean it well, I have had great success painting the entire bell with high quality oil resistant paint, with the exception of under the king bearing caps. Don't paint there.

In the "closed knuckle design" Dana uses a goop bath of lubricant to lubricate both the U-Joints or CV's and the King Pin bearings. With the advent of sealed universal joints that don't require re-lubrication, there is a "cleaner" way if you so desire. You can use sealed Spicer U-Joints (no grease zerk) and pack the King Pin bearings with wheel bearing grease. The "no grease zerk" u-joint is also much stronger. You will not be filling the knuckle with lube anymore. Then paint the whole thing. If you use this method you will need to re-pack the king pins bearings every now and then. In a show Jeep I doubt you will ever see them again. You will need to "wet" the felt wiper on the king pin housing bell seal with a little ATF or light oil, to help it wipe across the surface. It will no longer be lubricated. You have now created a "dry sealed" environment.This is the way I run mine. Somewhere I rattled on about this subject before!

[LTjackMB41]

Thank you, exactly what I was looking for. I will consider the alternative approach, but leaning towards keeping it original for now. However, I realize it is a new discovery every day.