Trivia, what,s this recess for on my rear axle ??
 

I have a decent collection of rear axles but only one with this 1 inch wide groove on the drivers side . Top side is pretty deep and runs to the normal smooth outer curve at the bottom of the axle. Other side is normal smooth curve all the way around. Looks like a recess for a strap. Axle had 1940 backing plates. 3rd pic is the smooth side.

Re: Trivia, what,s this recess for on my rear axle ??
 

POSSIBLE CUT LINES FOR A COLUMBIA 2 speed instalation ? ernie n tx

Re: Trivia, what,s this recess for on my rear axle ??
 

Hi Henry. Never seen anything like that before.
Is that the one from the snowmobile conversion?? Is it narrowed perhaps??

Mart.

Re: Trivia, what,s this recess for on my rear axle ??
 

Maybe some machinest has machined a groove in it in order to run it in a three point steady in his lathe? Brian

Re: Trivia, what,s this recess for on my rear axle ??
 

G'day Mart, Not from the Snowmobile , not narrowed.
Ernie might be onto something & Brian too, Only thing is the recess thins out to zero as it curves to the bottom side of the axle.

Re: Trivia, what,s this recess for on my rear axle ??
 

I have never seen anything like that myself. Cannot hazard a guess as to who has done what to the axel housing over the past 70 years. Doesn't look deep enough to cause any weakness.

Re: Trivia, what,s this recess for on my rear axle ??
 

Perhaps the metal was thicker than standard --but for the weld process to work properly it needed to be turned down some ---even part of an experiment for a new process.

Re: Trivia, what,s this recess for on my rear axle ??
 

Took another pic this arvo, do you see real old tack welds ?

Re: Trivia, what,s this recess for on my rear axle ??
 

I haven't seen that before, but one possibility is that it was the result of the casting mold having been modified. Many molds were used, producing slightly different results fore each mold.