A differential oil pressure gauge...

[cranetruck]

Installed the differential oil pressure on the 8x8, previously used on the deuce.
It displays the pressure drop across the oil filters and oil cooler. To my surprise, it indicated less than 1 (one) psi, I had expected about 5 or so based on the readings from the deuce. Now I'm wondering if the bypass valve is calibrated correctly or perhaps even disabled...

 

[SasquatchSanta]

If I'm understanding this correctly it sounds you're truck is at one extreme and mine is at the other.

I blew the seals out of the gauge that reads between the pump and the filters last winter.

I too wonder if the valve"s" are calibrated. (scratching head)

 

[cranetruck]

Having checked the bypass valve and replaced the filter elements, I have come to the conclusion that the less than 1 psi across the full flow filters is normal under the circumstances. The bypass filter keeps the oil "squeaky clean" and the full flow filters present little resistance.
Time and more driving will tell how long this condition will remain.