Filling rear end 1923 Hudson Super 6

rhurst

Does anyone know the purpose of the extra fitting on my differential? I see the plug to fill and the plug to empty but what is the purpose of the other arm and plug.  The only thing I can think of is it is a way to measure the about of fluid you put in not to exceed this level?  Anyone know the answer?

Robert

Geoff

It  is actually a sight hole for aligning the mesh of the crown wheel and pinion. 

rhurst

wow I never would have known that.  What do modern cars have to do the same thing?

Robert

Geoff

Modern cars are all pre-loaded and  not adjustable the same.  the principle is the same  but the construction totally different.

rhurst

I'm confused.....it has a right angle bend I would think you couldn't see anything?

Robert

Geoff

We are talking about the small square plug in the centre of the pinion housing, not the  curved filler fitting.

bob ward

I'd say the elbow fitting is the filler and the top plug is the sight hole. The top of the elbow would be the limit for the amount of oil that can go in the diff, to drain the diff turn the elbow 180°.

paulrhd29nz

The elbow stays where it is. The drain plug is on the bottom of the diff. 

rhurst

Thanks guys for straightening me out. I got it now. No telling what I will find when I drain it. I have the 600 wt steam oil to fill it with.

Robert