Overheating in NW Mountains

What rear end ratio do you have?

Proper gear for going up- you should be able to accelerate slightly. If you just have the hammer mashed, that's the wrong gear.

The steepest of the steep loaded at 78K gross or so I might be all the way down to 6th. Never had to hit low range.

Now if you have a freakish 2.something rear end, that may do it.

Most of the time I can go up the longest steep grades, loaded heavy, in 7th, that's 25mph at 1550 rpms. That's having the ability to accelerate slightly, even going up. That's the correct gear.

You're fan clutch should kick on and knock the temp down while climbing automatically.

If it's not cooling off, you're oil temperature is probably wtf sky high too.

You certain it's not oil temp causing shutdown?

 

That is definatly not normal... i run my engine fan whenever pulling a hill and it keeps it below 200 on just about any hill in america..

 

A blockage in the system maybe? Thermostat? What's your oil temp at. Get it looked at asap and put a manual fan switch in. You're killing the life expectancy. I'm surprised it doesn't have one from the factory.

If i was running out west in those mountains I would see if its possible to add another core to the radiator....after you figure out the issue. Turning the fan on at the bottom of a hill makes a big difference

 

Air flow through coolers restricted by bugs salt ice on a screen or water pump on its way out . Also verify that fan is actually spinning . With engine shut off see if it has play in it . I pulled 100,000 lbs over much steeper hills and longer with zero overheat issues with a 455 mx in the past .

 

If belt is squealing that probably you problem or first place to look. You need everything working correctly to pull the big hills.

 

And your belt squealing, if it chirps when you're idling, you have a tensioner or two that's probably shot.
That will shred your belt. $100 change is now $1,000 road service for the belt.
The tensioners are more. Upwards of $1,000 to replace all of them at a shop.