rear axle castle nut torque on 1930 Hudson Super 8

[timecapsule]

I'm wondering what the torque specs should be for the rear axle nuts on my 1930 Hudson Super 8.  I don't think that it's a slam dunk simple answer.

For one reason, the load on the bearing is not effected by how tight the axle nut is.  The bearings are further in and are independent of the axle.

The left and right axles are the same except on the left axle the threaded portion at the end, that the crown nut threads on to, is 7/8" dia.  On the right side the threaded portion is 9/16" dia.   Yes I know, very strange but there is no indication as to why they are different.  As I mentioned they both have a castle nut and cotter pin.  

There is one clue, that might indicate that one of the axles may not be stock.  It might be from an Essex.  But I have no proof and I don't know the axle nut size for an Essex.  Printed on the right axle in yellow paint is "21-31".  Making me think that that axle may have come from an auto wreckers some time during it's history.  

 

I just threw that tidbit of mismatched information in there to confuse everybody.  Nevertheless, I don't see how that might alter the torque setting.  The axles both have a typical taper that matches the wheel and it is keyed.

[Marty Roth]

1 hour ago, timecapsule said:

 The left and right axles are the same except on the left axle the threaded portion at the end, that the crown nut threads on to, is 7/8" dia.  On the right side the threaded portion is 9/16" dia.

 

Printed on the right axle in yellow paint is "21-31".  Making me think that that axle may have come from an auto wreckers some time during it's history.  

 I don't see how that might alter the torque setting.  The axles both have a typical taper that matches the wheel and it is keyed.

OK - the painted numbers are an indication that a junk yard (auto parts recycler in today's parlance) determined they could be used in 1921-1931 models.

My guess is that a 7/8" diameter shaft could take a vastly different amount of torque, compared to one of only 9/16" since it is more than 50% larger diameter

(7/8 = 14/16" compared to only 9/16"). There may also be a substantial differential in thread count per inch.