My hubs average 145+, and once you get up to temp they along with your axles will “howl”. The hotter it gets, the more the noise. Especially driving near non-stop from cali to georgia mine were LOUD.
Since you just purchased this truck, I’d highly advise changing all 6 hubs gear oil, and properly filling to Halfway level. Also check differentials to insure they’re not under/overfilled, as mine were GROSSLY overfilled and actually blew oil out onto the back of the cab on an extended drive through the vent tubes.
Change your transfer case oil, it uses 15w40 diesel oil. Do not put gear oil in it. IIRC it’s < 3 gallons.
Lastly, coolant temp should be between 185-195, fan kicks on around 210+-. Whatever you do, do not overheat the C12, it will crack a head in a heartbeat! The oil pressure will be around 10-15psi hot idle and 40-59 psi under load at high rpm per the Caterpillar manual specs. My truck personally runs 8psi indicated on the gauge at idle and 30 going down the road BUT the gauge is inaccurate and if you check the oil pressure via the TIM Behind your dash, my pressure is actually 12 at hot idle and 47 going down the road.
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