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RV Clinic June 2015

Originally Published in Trailer Life Magazine

Overheating Furnace

Q: I have a 2001 33-foot fifth-wheel, a National RV Palisades. It has an Atwood Hydro Flame furnace. I set the temperature to 75 degrees, and the furnace gets too hot and will not turn off. I have to turn it off at the wall. It is dangerously hot! I think the furnace might catch fire. Is there a part that is wrong, such as the wall gauge?

Dan Archuleta, via email

A: I’d recommend you not use the furnace until you get this condition repaired, Dan. It seems like the thermostat is bad. The fact that the furnace keeps going and possibly overheating suggests that the thermostat is in need of replacement. Your authorized RV service center can replace the thermostat. Alternately, if you’re handy with this kind of work, you can do it yourself. Heat-only thermostats are available at RV stores and most home-improvement stores. The furnace also has a high-limit switch to protect the furnace when a thermostat fails. It may also be faulty and can be replaced with a new one available from most RV stores.  — Jeff Johnston


USB Plug-In Option

Q: Regarding the “USB-Plug Addition” letter in the February 2015 RV Clinic, how about using a 120-volt AC USB charger? You can put it in a drawer when not using it and move it to a new trailer when you upgrade. I found several on eBay, including one for $5.95 with free shipping (shoot, at this price, get two). This one has a 120-volt AC adapter and a car cigarette lighter adapter for charging on the go. Be sure it has a high enough amperage output for your needs. You can also find these in thrift shops, if you look hard. I also have a standalone USB four-port hub to charge my backing-in walkie-talkies. Because of thrift shops, I have cell-phone chargers that live in my trailer, truck and car.

Jerry Elzea, Ettrick, Wisconsin

A: Isn’t variety wonderful, Jerry? Those 120-volt AC plug-in chargers are a good option for charging your USB devices, and they’re low cost, as you suggested, and readily available. In some RVs with minimal AC wall outlets, having an outlet occupied by a charger or two means you can’t have anything else plugged in at the same time, and for people with a lot of plug-in appliances, that can be a minor problem. Use of the USB-equipped sockets avoids that situation and also means you need to have only a USB cord on hand instead of the entire charger cord. RVers have flexibility about how they solve their USB-device charging, and integrated wall plugs are one good answer. — J.J.


Front-End Bounce

Q: We traded our 1995 Dutchmen fifth-wheel for a travel trailer so my wife wouldn’t have to climb steps inside the trailer. This is our first experience pulling a travel trailer after 20 years with a fifth-wheel.

We have a 2007 Chevrolet 2500HD Classic diesel 4×4 crew cab with the factory tow package and Allison transmission. The pickup has 25,000 miles on it. Our new trailer is a 2015 Rockwood Windjammer by Forest River. It is the V-front model. We have a Blue Ox weight-distributing hitch, which was installed by the dealer when we bought the trailer. The technician told me when he was installing the hitch that he didn’t think I needed it very badly because the pickup’s back end went down only about an inch when it was hooked on, so the back springs must be good.

The problem I have is, when we hit a low spot or a high place in the highway, it bounces the front end of the pickup up and down more than I think it should. The hitch is set like the dealer set it, but I am wondering if the chain is too tight or if the pickup needs better shocks on the front end. If the shocks are the problem, please recommend what I should replace them with.

Marvin Mercer, Grant City, Missouri

A: I know the feeling you have with the front of your truck, Marvin. I’ve experienced that several times in the past. In my experience, a bouncing front end is caused by a weight-distributing (WD) hitch with spring bars that aren’t adjusted tightly enough. It means the trailer hitch weight is removing some weight from the front of the truck, and that causes a lightweight or almost floating type of feeling at the truck’s front end. When you hit the bump you mentioned, the front of the truck bounces too much, due to the unwanted weight shift toward the back of the truck.

It’s true that the back of a sturdy pickup will drop less than, say, that of an SUV under a trailer’s hitch weight, but the WD hitch still needs to come into play to produce equal weight distribution on the truck’s front and rear axles. Test-drive your truck and trailer, then try taking up another link in the spring-bar chains to increase the tension on the spring bars. It may even take two links to arrive at the best adjustment. I’ve gone through this process many times, and it takes some trial and error to arrive at the best setup. Better replacement shocks such as Bilsteins may help too, but the WD hitch is key to the process. — J.J.


Wet-Cell Versus AGM Batteries

Q: I have been using a pair of 6-volt wet-cell batteries for seven and a half years; they are still working well. At some point I will need to replace them. I have studied the AGMs for a while, and the benefits are faster recharge, no maintenance, deeper discharge and longer life. What I am not sure of is comparing a set of two wet-cell batteries rated at 200 amp-hours and a set of two AGM batteries rated at 200 amp-hours powering the same load. Will the AGM batteries last any longer than the wet-cell batteries before recharging?

I have two 100-watt solar panels, and they do very well charging my batteries. I use two TV sets, not at the same time, and LED lights. The only time I have an issue is if I run the furnace before sun up. I don’t let the batteries get below 12.25 volts before turning off things or starting the generator, which I would rather not do. I don’t want to spend the money for the AGMs unless they will last a little longer before recharging.

Don Westenskow, North Logan, Utah

A: Regardless of the type of battery, 200 amp-hours is 200 amp-hours, Don. As long as the new batteries are rated the same as the old ones, you should expect similar performance.

The fact that you have 200 watts of solar panels wired to a pair of 6-volt cells, yet you have furnace operating problems by morning, tells me there’s something else amiss with your electrical system. For example, your current batteries may not be in as good of shape as you think they are. Seven and a half years is beyond the normal lifespan for batteries, and it may be about time to replace them. With a reasonable amount of daylight and sunlight charging your batteries all day and your modest power consumption, as you explained, you should have more than enough power to operate your furnace.

Check all of your electrical connections for damage or corrosion and have the batteries tested as well. Likewise, you may have an older, less-efficient solar-charge controller, so checking into a newer model may also serve you well. The guys at AM Solar (www.amsolar.com) can provide some terrific and knowledgeable advice on your controller options. — J.J.


Suspension Cracks

Q: I have a 2010 Cardinal fifth-wheel, which had a tire blowout coming home from Quartzsite. While changing the tire, I noticed there was a good size crack in my Equa-Flex leaf-spring suspension mount right above where the inner gusset is welded. After emailing Lippert, the tech department there wrote me and stated that it looked to them like the top bolt had been overtightened, and that’s what caused the crack. I’m writing this not to throw stones but to maybe prevent one of our fellow RVers from having a breakdown on the highway. RVers, make sure when you do your walkaround before leaving on your trip that you take a look in between your tires and make sure all suspension parts are in good working order.

Riverside Bob, Riverside, California

A: Thanks for the note, Bob. That type of damage can happen to the best of products, even under proper usage conditions. It’s always a good idea to spend some time “counting the parts” to avoid potential trouble on the road. — J.J.


Tire Replacement Timing

Q: My RV is parked indoors 300-plus days a year. It’s a desert climate, indoor temperatures average between 40 and 85 degrees, it’s driven every month, and the tires have modest mileage and wear. They’re Michelin LTXs, the sidewalls look new, and there are no cracks. Do I really need to throw them away just because they’re eight-plus years old, as they were manufactured in June 2006?

Mike Garner, Richland, Washington

A: This is one of those technical questions that should be answered, “It depends,” Mike. Those tire-age replacement specifications are general rules for typical tire use. As you explained regarding your RV, the tires seem as if they’re in really great shape, even though they may have technically “timed out” on age. Michelin maintains that tires can be kept as long as 10 years, provided they are properly maintained, and the rig is stored indoors (as yours is) and is not exposed to UV rays for extended periods. The lack of small sidewall or tread cracks is especially telling, as these are among the first signs that it’s time to consider tire replacement even if there’s lots of tread left. I’d say keep a close eye on those tires and inspect them every six months or so and replace them if necessary. But once they hit 10 years, it’s time to say goodbye. — J.J.


First-Time Trailer Purchase

Q: We’re looking at purchasing our first travel trailer, and I have the Forest River Surveyor Sport 220RBS in mind. Its dry weight is 4,415 pounds and a little over 25 feet long, hitch to bumper. I’m also looking at the Grand Cherokee (6,500 pounds and 7,200-pound tow capacity). I have been told that a pickup with a longer wheelbase would be a better option. Any recommendations?

Paul Kicklighter, Stafford, Virginia

A: When shopping for RVs, it’s important to avoid the trap of using “dry weights” when making buying decisions. The trailer will probably never weigh that little when it is in your possession, and this number can lead you to select a tow vehicle that does not have a sufficient tow rating. The gross vehicle weight rating (gvwr) represents the maximum amount that trailer can weigh when fully loaded and should be used as a guideline when choosing a tow vehicle.

Wheelbase is just one of many factors to consider in a tow vehicle. There are many factors that affect how well a vehicle works as a tow vehicle, including suspension, rear overhang, wheelbase, powertrain, etc. SUVs and pickups work well for towing, as long as they are rated and capable of towing the actual load. Longer wheelbase vehicles tend to be more stable when towing than shorter wheelbase models, all other factors being the same. — Ken Freund


Wheel Chocks

Q: We have a Wildcat 31ST from Forest River. I have always chocked the wheels with X-Chocks, which go between the two wheels first, and then I unhook and level my fifth-wheel. I have installed the Level Up six-point hydraulic leveling system. Now I do the same as before: chock the wheels, unhook and press the level button. The problem is that, when the trailer levels up, it takes some weight off the springs, causing the wheels to move slightly together. This puts excess stress on the chocks and even bends the tire treads inward. That is a lot of pressure! The question is, how can I chock the wheels before I unhook? I believe it is too dangerous not to chock the wheels first.

Albinas Butler, Pointe Claire, Quebec

A: Chocks that go between the wheels and press against the opposing tires do an excellent job of preventing the trailer from moving around but are perhaps a little too much during the leveling process, when some flexibility is needed. Since campsites are fairly level, there should not be a lot of pressure from the trailer trying to roll (against the chocks), due to any incline.

Therefore, instead of the X-Chocks when leveling, I suggest you use conventional separate wheel chocks on both sides of just one tire of each axle on each side of the trailer. Then, after you have the trailer leveled, install the X-Chocks, if you want to stabilize the fifth-wheel. You can also install the X-Chocks at the start, as you have been, but leave them adjusted a bit loose to allow for tire movement when leveling the trailer. Once the trailer is leveled to your satisfaction, adjust the X-Chocks. — K.F.


Cummins Diesel Concerns

Q: I hope you can help me, as I’ve been to every site on the Internet I can think of with no luck. I have 2003 Dodge 2500 pickup with a 5.9-liter Cummins diesel, which I bought last year. I put an Edge tuner in so I could monitor the exhaust gas temperature (EGT) and automatic transmission fluid temperature. I need to know the maximum recommended temperatures for both and how long you can run at max until you need to pull over. I pull a 33-foot fifth-wheel trailer.

Steven Carter, Sonora, California

A: It is important to monitor these temperatures when towing a heavy trailer, especially with a tuner, which may potentially increase EGTs. The EGT, if it is measured after the turbocharger, should not exceed about 1,000 degrees Fahrenheit.

If the temperature is measured in the exhaust just ahead of the turbocharger, peak temperatures should be kept at or below 1,300 degrees F. Transmission fluid temperatures should not normally exceed 240 degrees F, because when the torque converter is locked up, temperatures typically don’t climb above that. However, if you see temperatures in the neighborhood of 275 degrees F, you should pull over immediately and allow the engine to fast idle in Park to allow the fluid to cool off and circulate.

If you find that EGTs are too high, you might consider installing an aftermarket intercooler and a low-restriction air intake. If transmission temperatures are too high, an auxiliary cooler should help. Of course you can always back off the throttle a little, too, which is free. — K.F.


Check Those Lug Nuts

Q: My wife and I were returning from our third outing with our new Jayco Jay Feather when we heard a noise like we were driving on a rumble strip. After pulling over to a wide spot in the road and a quick inspection of the towing vehicle and the trailer, I found that the wheel on the left-side trailer tire had enlarged lug stud holes and badly worn studs and lug nuts. After installing the spare tire using three of the best lug nuts and two from the right side, we limped home after tightening the remaining right-side lug nuts.

A nearby tire shop replaced the bad studs and lug nuts, and mounted the tire on a new wheel. I asked the shop manager if he had ever seen anything like this before. He replied that this sometimes happens when new painted steel wheels have been installed with insufficient torque on the lug nuts and the paint layer in the lug nut seats wears through, allowing the wheel to work loose. The lesson here is to always check the lug nuts when checking tire pressure, especially on a painted steel wheel. We consider ourselves very lucky. Had we not stopped to investigate as soon as we did, the results could have been catastrophic.

Rich Woolverton, Arvada, Colorado

A: This points out an often-overlooked item. Trailer lug nuts should be retorqued to factory specifications after about 100 to 300 miles or so whenever the wheels have been removed and freshly installed. They should be tightened in sequence until all are done.

Painted steel wheels are generally less prone to lug nut loosening because the wheels are designed with a degree of “compression” in the lug seat area so the lug nuts squeeze the metal down a bit when tightened. This tends to help grip the nuts and deter loosening. Cast-aluminum wheels don’t compress this way; the nuts are tightened against them only. That’s not a problem at all, unless you don’t do your maintenance. In any case, the lesson is the same: check those lug nuts for tightness. — K.F.


Fan Cycling Finale

Q: This regards “Fan Cycling Sound” in the January 2015 RV Clinic. In that reply to me, you explained the operation of a thermostatically controlled viscous fan clutch and discussed the likelihood that my truck may have a clogged radiator.

We were finally able to find the problem with the cycling fan. After five different so-called experts had their shot at this issue, I finally found a place where solving the problem was their number-one goal, and they did. How all the rest of the so-called experts missed it is beyond belief.

Ken, your comment about the radiator was spot on. The amount of clogged area and the amount of crud they were able to remove was mind-blowing. They took it step by step and verified the clutch assembly, and then went straight to the radiator. There actually was some thought process, as opposed to replacing something and sending me the bill. Everything else was checked to ensure they got the culprit.

Noel Merkley, via email

A: Thanks for writing, Noel. I’m really glad the problem is solved. We seldom hear back from readers after we try to help them and therefore never get to know if our advice sent them in the right direction or not. Feedback helps us fine tune and focus our answers to constantly improve our responses. — K.F.


Tow Rating Tussle

Q: I own a 2013 Ram Big Horn 1500 4×4 pickup with a quad cab and 5.7-liter Hemi with eight-speed automatic transmission and 3.55 gears. The dealer told me that towing capacity was 10,000 pounds. So now I see this 6,900-pound rating. Was I lied to?

I tow a 24-foot trailer that has a towing weight of about 6,400 pounds without gear and water (which could easily exceed 1,000 pounds). Should I have gotten a 2500 series truck? And does the 6,900 pounds mean total truck and trailer weight?

Also, all four corners have coil springs, so I experience a lot of sag on the rear when towing. With a crosswind, I have to slow to 45 mph to maintain steering control.

Dave Jones, Watertown, South Dakota

A: On www.ramtrucks.com, the factory lists the gvwr as 6,800 pounds, which is how much the loaded truck can weigh if you put it on a scale. I’m thinking that you got your 6,900 number from a similar chart. The good news is, your actual maximum tow rating for your truck is 8,650 pounds, which may not be as much as the salesman told you but should be sufficient to tow your trailer.

Regarding the sag, that indicates you either don’t have a weight-distributing hitch, or it isn’t tight enough. Properly set up, the WD hitch, as the name suggests, distributes the hitch weight equally between the truck’s rear and front axles. If the rear end sags, you need to tighten the spring-bar tension — take up another link or two on the adjustment chain, for example — and if you aren’t sure about doing that adjustment, take the truck and trailer to an RV dealership with a service department, and it can set you up in no time. — K.F.


Frozen A/C Coils

Q: We were towing our 2006 Fun Finder down to Kentucky, and we stopped halfway there and camped. Overnight, we turned on the air conditioning. In the morning, it had frozen coils (it was on Low). It thawed out with just the fan on high. It never froze up all week until I turned it on Low. Any ideas?

Les Carr, Racine, Wisconsin

A: Airflow and humidity are big factors in the formation of ice in air conditioners. If the flow of air over the coils is reduced, it allows the coils to get colder, until their surfaces dip below the freezing point of water. Airflow may be further restricted if an air filter is dirty and clogged. When the air is humid, this creates a situation where ice forms from the condensation. Check the filter frequently and adjust the controls so that the temperature setting causes it to not get as cold, and run the fan on high speed when conditions still result in icing. — K.F.


Truck Heats Up II

Q: This is in regard to the letter “Truck Heats Up on Grades” in the March 2015 RV Clinic. I had the exact same problem with my 2001 Dodge Ram 3500. As you suggested, the fins were plugged in the radiator. I cleaned them with my pressure washer, and the problem was solved.

Mark Hansen, Salt Lake City, Utah

A: Radiators can clog internally from minerals in the water building up a coating in the tubes, and this may eventually stop water from flowing through the tubes. This is common after about 10 years or more. External buildup of dead bugs, mud, leaves, trash, etc. also blocks the airflow over the fins and can occur even with a nearly new vehicle. Either internal or external conditions such as this insulate the heat transfer and lead to running hot and overheating.

However, be careful about using a pressure washer on the delicate fins. This can bend them and close off airflow. It’s safer to run a garden hose (which has much lower pressure) from the back of the radiator aiming toward the front to blast dirt and debris out of the fins. Look down between the air-conditioner condenser and front of the radiator to make sure no debris is trapped there. This is a good thing to do whenever a warm-weather trip is planned. — K.F.


The Tech Team

KEN FREUND: Ken is a former ASE Certified Master Technician, service manager and shop owner who has authored numerous books on automotive repair.

JEFF JOHNSTON: Jeff served as technical director of Trailer Life for 20 years and has been an RV enthusiast, mechanic and writer since he could hold a wrench.


RV Clinic from June 2015 Trailer Life

RV ClinicRV Q&ARV Questions and AnswersTrailer How-ToTrailer Q&A

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