bardani

Learning To Drive A Diesel Motorhome

25 posts in this topic

Hi, everyone. This is my first time using this site. My husband and I just traded in our 35-foot gas Class A motorhome and bought a used 43-foot diesel. We will be picking it up this weekend.

While we have experience driving the gas RV, we are feeling a little nervous with our new purchase. We know there will be a four-hour demo but am not sure what they will cover. Going from a gas to diesel is a big change for us, as is the length. We want to take a trip out West in the next couple of years and will need help in learning how to drive in mountainous areas. Any advice on any classes that might be out there in or around Michigan that teach beginners on how to drive a diesel?

Thanks for your help/advice!

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I bought my first RV two years ago, a 36-foot Winnebago diesel, and after NEVER driving an RV before, felt very comfortable after just one road trip. The biggest difference is that with an exhaust brake, you will learn to anticipate your stops, let the Jake brake do the work, and just use the service brakes to come to a full stop. Other than that, it is a pleasure, compared to my friends' gas, as the engine is in the rear, so the cockpit is quiet.

Also, when sleeping while boondocking, the genset is in the front, so the bedroom is much quieter than gas. Other than that, it is all about the maintenance, more oil, and a filter/desiccant on the air brake line, that needs to be changed every three years. Also, the diesel is more sensitive to the cleanliness of the air filter and fuel filter(s). Relax and Enjoy the air suspension ride!

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Bardani,

Welcome to the Forum.

One of the first things to remember about driving a diesel pusher is to remember the location of the front wheels. In a car they are in front of you, in gas coach your wheels are almost right under you and with a D/P they are just behind you. So remember this when turning.

Also on any motor home remember the swing of the rear end. With your experience with your gas coach you should have no problem.

One thing I always say in maneuvering a Motor home "Slow and East".

Good Luck,

Herman

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Bardani, Welcome!

The Big item that one needs to understand is the Compressed Air system. How to bleed of the primary and secondary air tanks to remove water from the Primary and Secondary air tanks. What the air gauges are monitoring. What to do if the warning buzzer goes off. How to run a pre trip test of the system.

If the air pressure drops below 45lbs. the E breaks will come on and the coach will stop real quick.

I often tell new owners to find a school bus driver who would go over the air system with them and offer some driving tips. school bus drivers run a pre trip inspection before every run.

Then you can start learning the service requirements of the air system.

You should notice a real difference in the way it stops, the ride and the way they handle on the road in general.

Everything else is the same as a gas coach, with a few more amenities.

Enjoy your new ride !!!

Rich.

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Another important item, if your state requires a higher level/class of driver's license for diesel, take the time to get it ASAP. North Carolina requires it for any vehicle over 26,000 lbs, and/or air brakes. In our litigious society, the last thing you want is to be sued over the technicality that you had the wrong license class, regardless of fault. Also, my state Class B test is very informative in the above mentioned pre checks, and functions of the air brake system. Ditto on the draining of the air system, and also always check for water in the fuel/water separating filter. As for the turning, with the wheels behind you: easily mastered, after a little practice, but fun to watch the other drivers face, as you make a turn towards them, while rounding corners!

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Herman is correct about the length and "swing out". That extra 8 feet will take some getting used to because it can clip fuel pumps, stop signs, etc. if you are unaware.

Don

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Most pushers are longer between front and rear wheels, and shorter behind rear wheels and rear end of the coach. This is the most noticeable difference in driving a gas model and a pusher, and requires some getting used to.

Pusher requires a longer forward move than the gas model and will require getting used to. The other post are also correct, although the overhang on the rear will not be as cumbersome as the gas, still have to be careful for the overhang,

but not as likely to take down those stop signs with the overhang but more likely to take them down if you forget the extra length in the middle. As stated in other post the ride is superior, and air brakes will take some getting used to.

Happy trails, and good luck on the new acquisition.

Kay

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You will find, however, that the ride will be MUCH improved on the diesel, causing less driver fatigue that your old coach. Fatigue can lead to errors. Less fatigue equates to fewer errors. Your offtracking (the amount of space the rear tires turn inside the front tires on turns) may be greater because the rear duals and tag are further from the front tires. Plan your turns so you don't run over something with the rear tires when turning a corner.

Your new coach will have a tag axle. Remember, in slow maneuvers, raise the tag. This will result in less "scrubbing" of the tag tires. So when maneuvering into or out of a parking spot, lift the tag, especially on paved roads and sites.

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Your new coach will have a tag axle. Remember, in slow maneuvers, raise the tag. This will result in less "scrubbing" of the tag tires. So when maneuvering into or out of a parking spot, lift the tag, especially on paved roads and sites.

Good catch, Medico. I have seen drivers flat spot a tag axle tire leaving their site more than once.

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It's something that's very easy to forget, believe me I know from personal experience. Like I said it's worse on paved road, but even gravel roads can cause problems. These tires are way too expensive to let something like this ruin the tag tires.

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Why would turning cause flat spotting of the tag tires? I have a couple million miles in a long wheel base Peterbilt, pulling a 53' Reefer. Everyday, did a LOT of short turning, jackknifing back into parking spots and docks. Not ONCE flat spotted a tire, having two sets of tandems, one on tractor, one on trailer.

At times jackknifing, the trailer axles would stand still, and pivot! I owned the trucks and trailers, and paid for the tires. The same tires used on big diesel pushers. I would get 200k or so on retreads on the trailers!

So, how does turning flat spot them, when the DP cannot turn nearly as short as either the trailer or my Pete?

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Most pushers are longer between front and rear wheels, and shorter behind rear wheels and rear end of the coach. This is the most noticeable difference in driving a gas model and a pusher, and requires some getting used to.

Pusher requires a longer forward move than the gas model and will require getting used to. The other post are also correct, although the overhang on the rear will not be as cumbersome as the gas, still have to be careful for the overhang,

but not as likely to take down those stop signs with the overhang but more likely to take them down if you forget the extra length in the middle. As stated in other post the ride is superior, and air brakes will take some getting used to.

Happy trails, and good luck on the new acquisition.

Kay

I am not familiar with the length of a gas coach behind the rear axle but our pusher (mid-engine) is 14 feet.

Don

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First, both the axles on the tractor are drives and (I'm not sure of exact verbage) drive axles have variable differentials That change speed of tires that are turning a shorter radius. For the trailer, your talking 4 tires per side, And possibly the same type differential axles??? that the tag axles (with one tire per side) do not have. These are somewhat guesses, but reasoned guesses based upon driving both tractor trailers and tag axle coaches.

The tag tires will not flat spot each time the are turned short while on the ground, but they may have a cumulative affect. Again, just guessing.

Also coach tires sit in one spot for long periods, sometimes months at a time. A tractor trailer tires will be rolling continuously in most cases and will continuously exercise the sidewalls of all tires.

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There are no differentials on either the tag axle, or the trailer axles. Each wheel end is free to turn on its own. No connection to the other side on either. The tractor drives are driven thru a differential, but I do not see what difference that makes.

I am NOT saying it is wrong to lift the tag. It will lessen the scrub in turning. It is just that I do not think, for most cases, it will make a difference. Seems like almost everyone complains about aging tires out, getting too old, before they are worn out.

There are some risks to lifting the tag. It puts more weight on the drive axle. It increases the risk of bottoming out on the rear if the road is not level. There is a risk that you forget, and take off down the road with the tag lifted.

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The next time you visit a coach dealership take the time to observe the tag tires. Look at the sidewall near the bottom of the treads. On coaches where the driver failed to raise the tags you will find slight separation. Recently, I noticed this separation on the tag tires of a 2010 King Aire; the tires looked great overall except for this one area where the sidewall was separating at the bottom of the tread--it does make a difference when the tag is not raised on slow, very sharp maneuvers. I only wish I was more consistent in raising my tags--and on most coaches the tag automatically lowers when the coach reaches 2nd gear.

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Did you interview the previous owners to see if they raised the tag or not? If not, how do you know if they did or not?

I have seen this separation on single axle tires also. Obviously, they could not be lifted, but they would not scrub either. I have seen it on steer tires.

I have seen other tires without it.

I have seen tandem trailer tires, that scrub MUCH more than tag axle tires in jackknife situations, both develop, and NOT develop, these cracks.

I have put over 100,000 miles on trailer tires, AFTER these cracks develop, without a tire failure.

Again, I am NOT against raising the tag. I just do not feel that it contributes to early tire failure.

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You have experience with a 35' gas Class A, so I do not think it will be a big transition to a 40' or so diesel. I think you will drive it ok with practice. Go to various forums, and keep reading on diesels. You will get a pretty good education.

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mpierce,

You are correct that turning with the tag axle down won't cause flat spots. However it will help when making really short turn by just eliminating the drag of the tag wheels. But again you are correct the you should lower the tag once you have completed your turn. My Dynasty has an alarm that sounds when in drive. The problem is the alarm is at the exact pitch that I can't hear. But be assured the DW will let me know to lower the tag.

Herman

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Good catch, Medico. I have seen drivers flat spot a tag axle tire leaving their site more than once.

What is meant by "flat spot" or "flat spotting?"

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If a tire is not rotating (brake on, particularly if not much weight on tag) it can grind away the rubber from the side of the tire on the ground.

Same thing in a panic stop where the wheels are locked-- easy to do with an unloaded trailer.

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The Goodsams RV Plus credit card will save you 10 to 12 cents off the credit card cost of diesel at Flying Js and Pilot truck stops. Additionally you don't have to go into the Service center/ Restaurant to pre pay for the Diesel. The credit card works at the pump. I fill up where the trucks do. You have much more maneuvering room than in a gas filling station.

I took driving classes from the RV Safety Association when we got our RV. The best thing I remember from the school is ---"remember it is a recreational vehicle so go slow in any change."

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This is an important topic for me as well! I have only driven a 30' gas class C prior to now. We just purchased a 2014 Fleetwood Discovery 40X (around 41'6")...I have signed up with the RV Driving School for later this month to learn how to drive this beast. I have to admit I am scared to death because ultimately I will be towing a Honda CR-V behind her. She is still at the dealership which is 45 miles away, so I will have to drive her to our storage place before taking the class (to which I am going to have to drive about 40+ miles to meet the instructor).

BTW there are no tag wheels on our model...thank God!

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If your new coach is on a Freightliner Chassis, I can strongly recommend the Camp Freightliner classes offered at Gaffney, SC (Freightliner Custom Chassis Factory & Service Center). It was/is a 2 day class that covers diesel operation and maintenance of the coach. Well worth the price of admission, and you get information specific to your particular coach. Tips on driving in the mountains to prevent overheating, increasing your fuel mileage, mechanical emergency procedures, spare parts recommendations, etc. I would strongly suggest taking the class as a team so that both of you have at least a rudimentary understanding of the "why's" & "how to's". Mike Cody taught our class & knows the subject matter as it relates to Freightliner better than anyone we've come across. He will provide you with a notebook that you can reference long after the class. While you're in the class, get your coach serviced by one of the best service centers in the country, IMO.

Enjoy the new coach...you're gonna love the differences over your old gasser.

Strong tailwinds & smooth landings.

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