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Mrgunguy's avatar
Mrgunguy
Explorer
Jun 16, 2020

Climbing steep grades...

I have a 30’ 2003 Four Winds class C with the 6L, 8cyl Vortec engine. I’m planning on pulling a 2003 Jeep TJ (4cyl, straight drive) and had a question or two.

I’ve noticed that when I’m climbing steep grades (or even not so steep grades) the engine has a tendency to begin heating up. I’ve been told that this is due, in part, to the overdrive and if I simply kick it down to 3rd gear I should be able to mitigate some of that heating. So far, so good. It does heat up some but not as quickly as it used to and it has not left me on the side of the road with a smoldering engine.

Now I would like to flat tow a small Jeep so that I can run about when I get to where I’m going but I’m afraid that this will be too much and the coach will overheat when I’m 1,500 miles away from home and on the side of a mountain. Is there something that I should be taking into consideration or doing differently? We would like to go to see Yellowstone this year and, at an elevation of 5K+ feet, I’m feeling anxious over having to climb an awful lot of asphalt.

Any help or advice would be gratefully accepted.
  • ReneeG wrote:
    I'm not a Class A owner, but on more than one occasion, in our travels, we've seen the toad following the motor home by the other driver, up mountain passes.


    That’s a great idea and one that I had considered but would rather not do if I can help it. My wife can’t drive a stick and she would rather not drive the coach when she has to think about what she’s doing. She likes it flat and straight, LOL! But she’s a trooper and will do what’s needed if required.
  • pigman1 wrote:
    Unless you're going up the side of Mt Everest or your fan clutch is inop, your rig will probably handle any slope you choose to climb, and without overheating. The trick is that you DO definitely slow down. On a slope, watch the temp gauge and as it starts up, downshift a gear. If it's still climbing, drop down another gear. Of course, when you keep dropping gears you also have to slow down to keep the RPM's in a reasonable range. We regularly drive to Alaska pulling an 8000lb plus pickup and don't have any problem on those roads with grades up to 9%. I am definitely going slower, however. I have been down to 10-15mph on some really steep back roads, but driving this way does work. If you want to fly up any grade, trade your rig for a 600HP Cummins (LOL)


    Thanks, that’s helpful. I’ll just keep trimming gears until the fear subsides, LOL! It’s kind of what has become more and more apparent as I research this.

    And yes, 600 ponies would solve the problem nicely!! :)
  • I'm not a Class A owner, but on more than one occasion, in our travels, we've seen the toad following the motor home by the other driver, up mountain passes.
  • Unless you're going up the side of Mt Everest or your fan clutch is inop, your rig will probably handle any slope you choose to climb, and without overheating. The trick is that you DO definitely slow down. On a slope, watch the temp gauge and as it starts up, downshift a gear. If it's still climbing, drop down another gear. Of course, when you keep dropping gears you also have to slow down to keep the RPM's in a reasonable range. We regularly drive to Alaska pulling an 8000lb plus pickup and don't have any problem on those roads with grades up to 9%. I am definitely going slower, however. I have been down to 10-15mph on some really steep back roads, but driving this way does work. If you want to fly up any grade, trade your rig for a 600HP Cummins (LOL)
  • time2roll wrote:
    Running a bit warmer when working hard is completely normal. Just like going for a jog vs walking.

    Ultimately if it does approach "over temperature" you need to slow down and continue to downshift to keep the rpm up. If you have a tachometer the RPM should be 1000 to 2000 rpm above the peak torque when running hard up a hill. RPM of peak HP would be about max.

    Of course this would be a good time to have the 17 year old cooling system checked and cleaned. Check for debris stuck to the front of the stack that may restrict airflow. Check or just replace the fan clutch (I recommend OEM only). Check or replace the thermostat... seen plenty stuck half open and work fine day to day easy driving.


    Yeah, I know it is going to get hotter when working hard, it’s just that it gets soooo close to the red line. I don’t have a tach, but I was thinking of installing a computer to read this info (along with other stuff). At the moment I’m trying not to spend any more money on it than I have to due to wife aggro. I have had the whole system gone through by a Chevy dealer. Complete flush of the system, change all fluids, new brakes, tires, thermostat, etc, etc. I put about $2,500 into making sure everything is on point. I didn’t do the fan clutch but that would be my next move if it got too bad, though I think it’s working fine.

    The more I read about it and ask questions, the more it seems like 25 or 30mph up longer slopes might be the solution. I’ll just have to let the folks stuck behind me think I’m an A-hole.
  • 12th Man Fan wrote:
    Do you hear your fan clutch engage?Might not be able to hear it on thet type of engine but on my disel it sounds like a jet taking off. Might check and make sure the fan is operating correctly.


    I was told that the “jet taking off” sound is the overdrive kicking in and not what I want to hear when climbing. Whenever I hear that sound I know that I’m on a hill and I need to downshift. I’m guessing the fan is okey dokey.
  • Gjac wrote:
    Quite normal for a 30 ft MH to heat up on a hill. What temperature does your gage read on a steep hill say 7-9 % slope for several miles? Do you have a temp gage of just an idiot light? Does it get in the red zone? We need to know what you mean by overheat before you get meaningful comments.


    I didn’t say it overheats, only that it begins heating up. It runs just below 210 (the halfway mark on the gage) but when I start to climb it goes higher and higher until I stop climbing. It hasn’t overheated yet, but that is my fear should I find myself on one of those never ending climbs, which I expect to find on my way to Yellowstone.

    The highest “temperature” Ive seen is at about 235 or so, and the red line starts at about 250. It has not yet gotten into the red zone.
  • Running a bit warmer when working hard is completely normal. Just like going for a jog vs walking.

    Ultimately if it does approach "over temperature" you need to slow down and continue to downshift to keep the rpm up. If you have a tachometer the RPM should be 1000 to 2000 rpm above the peak torque when running hard up a hill. RPM of peak HP would be about max.

    Of course this would be a good time to have the 17 year old cooling system checked and cleaned. Check for debris stuck to the front of the stack that may restrict airflow. Check or just replace the fan clutch (I recommend OEM only). Check or replace the thermostat... seen plenty stuck half open and work fine day to day easy driving.
  • Do you hear your fan clutch engage?Might not be able to hear it on thet type of engine but on my disel it sounds like a jet taking off. Might check and make sure the fan is operating correctly.
  • Gjac's avatar
    Gjac
    Explorer III
    Quite normal for a 30 ft MH to heat up on a hill. What temperature does your gage read on a steep hill say 7-9 % slope for several miles? Do you have a temp gage of just an idiot light? Does it get in the red zone? We need to know what you mean by overheat before you get meaningful comments.