Options for upgrading cooling for towing.

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kd7vea

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Feb 24, 2022
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Spanish Fork Utah
This seemed like the best spot for this question. I have a 1987 Champion Euro coach 33 foot class a motorhome That we have been rebuilding and its coming down to the final pieces. I have a 5000 pound jeep and a 1500 pound car hauler trailer that I will be towing behind the motor home. The radiator has leaks, so I figure its time to get rid of the 1987 stock unit and replace it with a 4 core aluminum radiator. The motorhome is on a john Deere bus frame, ford 460 and a C6 transmission. I was going to ditch the mechanical fan and shroud and go with a dual 12" electric setup with built in shroud, but I have read a few places that I will be better off with the mechanical fan. A little HP loss, but better cooling. With the added 6500 pounds of trailer and jeep, want good cooling and a separate trans cooler with electric an fan. My question is, should I add 2 12" fans to the front of the AC condenser for added air flow, or is that not going to help/hurt the situation? I live about 180 miles north of Moab Utah, so there will be several trips up and down the mountain passes towing the trailer, and of course yellowstone and other surrounding areas. There will be a lot of hill climbing. any thoughts, or other items I have overlooked?
motorhome.jpg
 
I worded that a little weird, The jeep will be on an 18 foot car hauler with dual axles and electric brakes. the trailer itself is rated at 7000 pounds, so the combined weight of the trailer and jeep should be aroung 6500 pounds.
 
I think you are going overboard. Which won't hurt anything but may be more money spent than you needed to to solve the problem.

Adding a separate transmission cooler (assuming what you have now is internal to the stock rad) not only helps the tranny it also makes the rad more efficient for engine coolant (because it no longer has to cool tranny fluid). I don't see a fan as necessary on a tranny cooler, they are usually three or four times the size of stock and fresh air is enough.

Do NOT ditch the shroud. I'm on a bunch of auto repair forums and lists and the number of problems that occur when the shroud is removed are numerous and constant. Don't underestimate the importance of the shroud, you may have better cooling airflow with one fan and a shroud than two electric without. It seems like two fans would be better but it doesn't always work out that way.

I'm not personally a big proponent of electric fans. They require thermal sensors to work properly and they have a lot of potential failure points. I've found on a few vehicles that the real problem is that the fan clutch has begun to fail in old age and although the fan turns it doesn't reach the high RPM necessary when the engine is under full load. Some people jump to the wrong conclusion that they need dual fans and they go off on a tangent.

A good example was my Envoy, at an engine RPM of 3000 the fan was supposed to be turning at 3450RPM but with a weak clutch it was only turning at 1950RPM. To the naked eye/ear you couldn't tell that it was failing. Furthermore, it ran just fine without the trailer and no overheating with the trailer on flat road, when I tried to climb a mountain with the trailer on I'd overheat. A new fan clutch cured the situation completely.
 
A lot of those older coaches had electric pusher fans in front of the radiator in addition to the engine mounted fan. I wouldn't ditch the engine mounted fan(or the shroud), but I might add the electrics, on a temp switch so they only come on when needed.
How modified is the Jeep? I flat tow mine, and it's sure a lot less hassle than hauling a trailer too. Tow capacity on that old a coach is probably 5000lbs, so between the Jeep and the trailer, you'd be way heavy.
 
Old_Crow said:
How modified is the Jeep? I flat tow mine, and it's sure a lot less hassle than hauling a trailer too.
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It's got a few things done to it. 6.0 LS swap, chevy 6 speed trans, Artec 3 link, 37" Nitor mud grapplers... 1 ton axles going on it next year, and 40" tires. The 2 big reasons I want to tow on a trailer rather than flat tow are to eliminate tire wear, and less concern if something breaks. if an axle, steering, or suspension part breaks, I just have to get it back to the trailer, not 200+ miles I also gain the 2 electric braking axles on the trailer. I am absolutely open to recommendations if I am overlooking something. I just want problem free/safe trips.
 
JayArr said:
I think you are going overboard. Which won't hurt anything but may be more money spent than you needed to to solve the problem.
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I agree, but I would rather spend the extra money now if it keeps me from having issues later. We drove the jeep down to Moab last year and the Oil pump failed on the freeway just minutes before exiting into Moab, so we are all scarred from that trip. The radiator already has a few leaks, so that needs to be replaced. I'm also going to replace the water pump, alternator, power steering pump, belts, and hoses while I have the radiator out. it will cost an extra $350, but to do it while there is room to work and eliminate the risk of having issues on the side of a road is worth it.

I did more research last night and came to the same conclusion that you mentioned. I am keeping the stock fan and shroud, going from an old 3 core radiator to an aluminum 4 core. I need to trace the hoses, but it looks like I may already have an external trans cooler, and it would cost less than $50 to add a fan to that. I will see what it does as the temps outside increase and if it looks like adding a fan or set of fans on the front side of the AC condenser, I will add those later because that can easily be done without disassembling everything.

Summer trips in and around Utah can see temps over 100, and a bit more coming off of the asphalt. I am New to Motorhomes and just want things to go smoothly. There is enough other stuff I will need to fight through as I learn. I'm always open to any ideas or anything I may have overlooked.
 
My only thought is buying the deepest transmission and oil pans possible for the C6 and the 460. Nothing that would be vulnerable or dangerous underneath, but would hold a lot more fluid capacity which can = more cooling capacity.
 
Skookum said:
My only thought is buying the deepest transmission and oil pans possible for the C6 and the 460. Nothing that would be vulnerable or dangerous underneath, but would hold a lot more fluid capacity which can = more cooling capacity.
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Good idea, I hadnā€™t thought of that. Iā€™ll look into that.
 
kd7vea said:
It's got a few things done to it. 6.0 LS swap, chevy 6 speed trans, Artec 3 link, 37" Nitor mud grapplers... 1 ton axles going on it next year, and 40" tires. The 2 big reasons I want to tow on a trailer rather than flat tow are to eliminate tire wear, and less concern if something breaks. if an axle, steering, or suspension part breaks, I just have to get it back to the trailer, not 200+ miles I also gain the 2 electric braking axles on the trailer. I am absolutely open to recommendations if I am overlooking something. I just want problem free/safe trips.
Click to expand...

Yeah, I might trailer that one, too. Mine's pretty much stock, with 31's and some flat fenders/flares. I was looking at a trailer so I could also haul a motorcycle, but just decided it was too much hassle for an old fat guy to carry all those toys around.
 
I'm not a big "fan" of electric pusher fans in front of the radiator. They work great at idle but they can block incoming airflow on the highway and actually cause overheating.

Shrouds can also block airflow at high speed. Especially limiting airflow around V8-V10 exhaust manifolds. Without a shroud airflow is diverted to the sides by the fan. If it doesn't overheat at idle you don't need one. Most truck engines have oversized radiators and can handle no load idle speeds with the factory fan only.
 
The shroud is already a pretty close fit to the fan, so there may not be room. One of my thoughts behind adding 1 or 2 12 inch fans to the front of the AC condenser to help push air to help with the AC cooling as well as help with engine cooling. Most of the camping we will be doing will be southern utah, so we will be seeing a lot of 100+ temps.
 
Just remember that with a fan on the front and back of a rad (or AC condensor) you can end up with a conflict. Unless the fans are moving air at the same rate you can end up with turbulence.

It can be difficult to push air into the front of the rad at a volume greater than the other fan is pulling it out. The fan on the engine is fixed through a viscous clutch and harder to make freewheel than the fan on the electric motor so it's unlikely that the electric motor will 'drive' the engine fan. If not done in a calculated way it could make things worse.

Try taking two house fans and aim one into the back of the other (same speed). Hold a thin strip of tissue paper up between them to see the air flow and then set the second one on a lower speed and have a good look at what happens.
 
Aside from the cooling repairs, modifications and upgrades, running the hills in high temps towing 7k will be a strain.

My suggestion is to plan your travels with temps and weather in mind. Running the hills at night or early morning is usually a better choice than running through them at peak temps. Not only for the engine but for tires, bearings and brakes too.

I have an old gas 454 class A and will tow the car with a dolly. Its a pretty good strain on the engine in the heat. Even without the tow weight, traveling in the hills can heat up the dog house pretty good. I pay close attention to this and will run at night if needed. Rain is also another factor. Rain has its risk issues but it does keep tires cool and helps remove heat from the engine in my rig. Early morning runs is a big favorite of mine. Sometimes I will head out at 5am and shut down at 11am or 12pm until night fall, run as far as I can then get some shut eye and head out early morning. My 454, tires and brakes like me very much šŸ˜Ž
 
Sorry to go off topic, but have you found any literature or parts catalogs? Specifically wiring diagrams for the Eurocoach or JD chassis? I'm in the midst of a similar rebuild and have found nearly nothing on them.
 
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