Hi,
I dissassembled my power steering box (-73) and figured out how the torque sensing for the power assist works. The power assist sensitivity is governed by so called reaction springs which look mainly like large thin shim plates. The idea of these springs and the whole assembly is to monitor the torque the user is putting on the steering wheel and according to the spring load put in there by the factory it moves the main spool in the power assist valve with a lever attached to the torque sensing assembly.
As I live outside US and try to save some pennies every now and then I decided that I will try to improve the firmness of the box by myself instead of ordering one from Firm Feel etc.
The easiest thing to make it more firm is to just add an another set of springs with the ones that are already in there and I've been sourcing for used power steering box locally. Now I have found one that is probably from a 71 Challenger thus it has the smaller diameter reaction shaft end. Does anyone know if the internals are otherwise the same and only the reaction shaft end is different?
Thanks in advance, if this works and I will get my steering more firm, I'll try to post somekind of DIY article about it. I've taken lots of pics sofar.