4020 engine oil pressure

Have a 1965 4020
At cold start it has roughly 60-65 oil pressure gauge wise.
And if reved it goes almost up to 80 psi. But once warm up it starts to come down at around 40-45 psi at low idle when at operating temp its about 15-20 psi. Is their anything wrong with those readings?

The factory rating is only 25-30 at running RPM.
That is also the approximate PSI of our N14s.

(quoted from post at 17:08:10 04/17/21) Have a 1965 4020
At cold start it has roughly 60-65 oil pressure gauge wise.
And if reved it goes almost up to 80 psi. But once warm up it starts to come down at around 40-45 psi at low idle when at operating temp its about 15-20 psi. Is their anything wrong with those readings?

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Here's what the official factory shop manual has to say:

Gasoline or Diesel. That is a huge variation in pressures.

Diesel

Just kind of curious here. Have you had this tractor long and has it been doing this all the time.

The reason I ask is the diesels had a crankcase ventilator pump on them. Under certain conditions these pumps would allow crankcase oil to be pumped into the engine. Usually from plugged air cleaner system.

A lot of those pumps were gutted or disabled. When doing that some often omitted plugging the oil lube hole that lubed them. This caused a low oil pressure problem. To over come this some would shim the relief valve trying to get more oil pressure. Of course that is the wrong thing to do as then the pressure is way too high with cold oil, high rpm's.

I worked at a Deere dealer for a few years and although the tractor I worked on was not shimmed, the pressure was very low when warm at low speed. Plugging that oil feed hole to the now gutted ventilator pump put the oil pressure where it belonged. I do not remember the correct pressure though.

A few 4010's or 20s lost the engine when running stationary on generators during snow storms that plugged the filters. Others just started smoking so bad and burning lot of oil that the plugged filter was found before damage to engine occured.

I'm not really a Deere man but that is how I remember it. I only worked there four years to finish up before retiring as I worked IH all my other years. Food for thought.