Switch to hypoid differential ?

[BINKYBOY]

Is there any advantage to switching a 1937 Dictator spiral bevel differential to a later hypoid differential ?  Is it even possible ?  Thank you.

[nvonada]

My 41 calls for hypoid lube.  I am not sure when Stude started using Dana axles though.  I use standard 80/90 gear lube and it seems happy.  

 

OK, I should have read the post more carefully Sorry...

Edited August 31, 2021 by nvonada (see edit history)

[Stude Light]

One of the primary advantages of the hypoid gear is to move the driveshaft down lower to allow the body of the car to be lower with a flatter floor.  So unless you need to modify the body to either lower it or flatten the floor, there is no benefit there.  Another benefit of the hypoid is the pinion gear is larger along with the gear contact area which allows for greater strength. So, for the same size differential housing you can run more torque through the unit.  This might be important to you if you planned to put in a higher horsepower engine.

 

The down side of the hypoid vs a spiral bevel is that you get more sliding friction at the gear teeth interface which requires special, extreme pressure (EP) additives to the gear oil, necessitating using a GL4 or GL5 (preferred) rated "Hypoid" oil. A hypoid makes more heat and is also less efficient than a spiral bevel - both of which go in the wrong direction with higher offsets.

[BINKYBOY]

Thank you, Stude Light.  That is the information I was seeking.  No larger engine planned, and no need to move the floor down, so I will stick with the spiral bevel.  Cheers !