How do you tell if the proportional valve is working

[Submariner]

how do you know if the proportional valve is working.  my MJ has been seating for 5 years, I am finding that I that I am starting in the front and working to the back,going from the ground to the roof to check everything and I am getting to the proportional valve and was wondering how can I tell if it is doing what it is suppose to do or should I just leave it alone.

 

has anyone had any dealings on this item?   thank

[Eagle]

Sorry to answer with a question but, before considering a response -- is your proportioning valve intact, with the connecting link down to the differential? Is the arm on the valve basically horizontal? I ask because, if the entire mechanism isn't there, the valve itself can't function as designed.

[HOrnbrod]

It supposed to look approximately like this with the valve arm roughly positioned parallel with the axle tube.