Do you have enough room in front of the rad to install an electric fan or 2? I had a girlfriend that had a 79 Corvette that ran hot from new, real hot, like 240 F.. I found that the problem was that the rad was sitting at a 45 degree angle and was sucking air around the rad. I installed an electric fan and it never ran over 200 F. again. Another option for this is to remove the original heavy fan and clutch and install 1 or 2 on the engine side of the rad, good luck...Mark

Radiator should be big enough. Tape (or use an aluminum filled epoxy )a thermocouple to the in and out fittings on the radiator, with a little insulation taped over them, then check the temps under running conditions. I'm willing to bet the outlet side is hotter than it should be. It takes a lot of airflow through the radiator stack to keep things cool.
Theoretically, it should take less radiator to cool a diesel than a gasser.

I would.....
1. Ditch the clutch fan and install electric fans.
2. If not enough, install a frame mounted fan assisted transmission cooler.

Do you mean relocate the front-mounted aux trans cooler to frame-mounted?

The picture of the cooler stack reminded me of some testing I did in Death Valley a few years ago. We were running Ford transit vans up and down the hill out of Stovepipe Wells and the vans would over heat halfway up the hill. We tried putting ice on the top of the radiators, running the heaters (lots of fun when it's 128 degrees) and everything else we could think of and nothing worked until we took the hoods off (the hood was only about 12 inches deep). After that they would run right up the hill at full tilt and not go above the normal operating temp. Those vans had a closed back dog house similar to what your MH has. Something about the areodynamics on those things caused the air to stack up under the van and make it over heat.

As a test perhaps you could do something like we did (I don't know what the options are on your MH) or make a run with the doghouse off and the windows open and see if it changes anything.

You might try removing the partition as well for test purposes. If it fixes it you could relocate the air filter to a cooler location.

It's a different unit, bolts to the frame somewhere near the middle of the truck. You can run them both, but the front one would probably be redundant.

Like brainfade said, I think airflow is probably the key, and close fitting electric fans would probably overcome some of the aerodynamics issues.

Is there any room to install a remote fan cooled radiator in side compartment?

Everything in front of your radiator produces more heat as the load increases, move as much as possible out of the air stream or provide excessive ram air for them, Ford Taurus fans move more air than aftermarket.

Is there an airfoil/ spoiler under the chin to direct air into the radiator, and how about directing the air out of the engine compartment?

Just a few inches can really screw up the aerodynamics of a vehicle.

I think most of those fans can push or pull air just depending on how they are wired up. My brother knows a guy that wasted a lot of time and money on four electric fans and custom shrouds just to find out the first two fans he put on were blowing in opposite directions and circulating the hot air around and around. he would have been fine if they were wired in correctly from the start but never checked to see what way the air was flowing.

If you can relocate that cooler then its going to be better, as you say, the heat that is being pulled out of the trans is going back into the intercooler and radiator.

Jim, the remote aux radiator is a novel idea. What trucks you know that use them? Unfortunately, the side compartments are taken, i need them for storage.

I think I can find room to relocate the trans cooler underbelly. I think this should be the first mod to make. The see if I can do the same with the A/C condenser. Then only the intercooler will be blocking the radiator.

And no, there is no air dam under the grille. It's taken by the 17.5k# winch.

Brainfade, I'll experiment driving it without the partition. I wonder how the intake will react to a warmer air. I can create a tunnel for the air intake later f the experiment proves the partition is keeping the heat.

It sounds like your on the right track now. Also have you been running A/C while it's getting hot?

I have a old ford tractor that does a lot of work chipping wood. It's job is to run a hydraulic chipper, it's a diesel engine. The radiator is a big boy but there are hot days were I have to check the gauge as it will get way to hot and I'll idle her to cool it down. I ended up tossing the thermostat to see how that would help the old beast. She hasn't ran hot ever since.

Maybe something to try? I know you have a tranny and other moving parts so maybe it won't help.

This is where my suggestion to actually measure the temp at both ends of the radiator comes in.
If there's a large temperature drop across the radiator, you have a water circulation problem. If the temperature drop is small, you have radiator or cooling air problem.

See if you can make a spoiler / air dam under the radiator area. Even if you have to fit it around the winch. This would force more air through the rad and or out the sides of the MH, at the same time maybe creating lower pressure under the MH thus drawing air out of the radiator and doghouse. It could be very simple at first, to see if it helps. Then build a nice one later if it works. Sometimes they even help fuel mileage.
I'd try another temp gage too. Just to be sure.
Ray

Try a product called "Water Wetter" made by Red Line.

Add a bottle to the coolant, it works good.

It helps the coolant transfer heat faster.

I used to have a small block chevy hot rod, would always overheat with the AC
on. After the treatment my coolant stayed at 190

Is there an air dam under the front bumper? This can work well ,as it directs air entry and exit.

I looked at it yesterday and concluded the winch mounting plate (inverted, the lips are pointing down, due to winch too large to fit inside lips) actually creates turbulence. I could fabricate an air dam and attach the ends to the rails where the winch mounting plate is suspended. The air dam would be below and behind the winch. I'm sure this will help.