wolfe10

emmabee10, Welcome to the FMCA Forum. The house outlet-- if it looks like the other outlets in your house (two straights and a round) is a standard 15 amp outlet. If your RV has a 30 amp shore power cord, you would need an ADAPTER (15 amp male to 30 amp female) to be able to plug it in. If the house outlet looks similar to your 30 amp RV plug, DO NOT PLUG IT IN. It is likely to be a dryer plug and will be wired for 220 VAC instead of 120 VAC. Please let us know about the house outlet you plugged into and we can go from there.

Paul, Contact your chassis maker. They are the ones who determine how the brake lights are wired.

Cookie, While weight is a significant factor in determining MPG on grades, it is far less important than aerodynamic drag when running on flat ground. While there are many factors affecting MPG, there are a couple that reduce motorhome MPG as compared with trucks. While trucks have their cooling systems (Charge Air Coolers and radiators) in front where the vast majority of the air flow is provided “for free”, diesel pushers have to run fans that provide this cooling—often at a cost of over 25 HP. Modern trucks are more aerodynamic than motorhomes. There is nothing “slick” about the aerodynamics of a motorhome, with its multiple awnings and multiple roof top items. And, with 10+ gears, trucks can operate closer to peak torque RPM which is more efficient than at higher RPM.

Slightly lean your coach to the side and on some, the end you prefer for the condensate to exit on. On ours, we lean it with the left side down so that condensation does not drip at the entrance door.

Carl, You are right, any 2X anything will crack very easily. Most crack resistant at reasonable price would be a sheet of 3/4" exterior plywood. Cut the sheet into appropriate size pieces. Glue and screw the pieces together orienting each layer at 90 degrees to the previous.

Yes, there are a number of ways that the engine brake (exhaust, compression or VGT) can be set up from the factory and then used by the driver. I do know that Caterpillar offers what I feel is the "ideal" factory set up. It is called Latch Mode. When the Caterpillar ECM is programmed for Latch Mode (by any Caterpillar dealer) and assuming the chassis maker has wired the ECM with brake switch input, here is how it works. Leaving switch ON all the time: Take your foot off the throttle-- you coast (like Tom, this is my favorite "gear"). Touch the brake pedal-- the engine brake comes on and stays on whether you stay on the brake pedal or not. Engine brake turns off when the throttle is touched. This allows the engine brake to be left on all the time for emergency stops, yet allows you to coast. If someone knows if Cummins offers the same, would be interested to know.

Actually, the vast, vast majority of tires that fail do not go from perfect to blow-out without loosing air first. Sure it can happen, but most loose air slowly, then really heat up and blow out/throw tread. That is why I consider a TPMS the same as an engine temperature gauge or oil pressure gauge. All three tell you about a problem and hopefully in time to prevent major damage.

Rich, Yes, we had been on the road all summer and has some "house chores" to take care of. So, as soon as I finished with the Seminars I present, we hit the road. No wind across OR and ID. Nice tail wind across WY. Then 20-25 MPH head winds in CO, OK and TX. Glad we were not in the sailboat-- would have had to wait for better conditions!

Carl, Likely a combination of things. We had the same experience this summer in Oregon. Clearly Oregon has its share of mountains. MPG always suffers on grades vs flat land. We also played "dodge the Bio-diesel" dance. Pulled into one station and right back out-- small print on the pump was B20. Biodiesel contains less BTU's per gallon, so MPG will suffer, but we are talking about 5-7%. So bio alone will not account for your experienced difference. No idea whether headwinds played a part in the equation-- we did not experience adverse winds in Oregon. Boy did we from Colorado on south to south Texas on the way back from Oregon.

Bill, Just a clarification-- with the Cummins B and Allison 3000 in your chassis, you very likely have an exhaust brake of some brand. Later model B engines used VGT turbos and did not have an external exhaust brake. The only coaches with retarders (built into the Allison) are some OTR buses and Foretravels. The names/brands of the exhaust brakes makes it difficult to understand, as some are called/labeled retarders. Look at the downstream side of our turbo in the exhaust system and verify what you have. I say this because some, like PacBrake require lubrication.

Don, From an article I wrote for the FMCA Magazine: ALLISON TRANSMISSION MODE BUTTON BY BRETT WOLFE, F252125 The Allison transmission control module (TCM), which is the "electronic brain" that controls shifting and other functions of the transmission, has two different automatic gear-selection modes/programs. In Economy Mode, the transmission will not downshift even at wide-open throttle until the engine pulls down to peak torque rpm in some applications and 200 rpm lower than Performance Mode in others. In Performance Mode, the transmission will downshift much earlier to maintain higher engine rpm. Only at higher throttle positions is there any difference, so on flat ground you will not notice any variation between the two modes, except when accelerating from a stop if you are at or close to wide-open throttle. However, mode selection can make a big difference when traveling over rolling hills. If you drive in such areas while in Performance Mode (particularly with the cruise control on), it is common for the transmission to shift down to fifth gear on the uphill and back to sixth gear on the downhill, repeating this process hundreds of times. In Economy Mode, the transmission will stay in sixth gear unless the hill is so steep or so long that the engine cannot pull it without dropping below peak torque rpm. According to engine manufacturers, the most economical way to climb a hill with a modern turbocharged diesel engine is in a higher gear (lower engine rpm), provided the engine doesn’t overheat. If, while driving in Economy Mode, you know you will need a lower gear because of the steepness of the grade and/or the engine temperature is rising higher than the thermostatically controlled temperature, use the down arrow to drop a gear (this is what I do) or switch out of Economy Mode. Be sure to switch back into Economy Mode when past the steep section or you will be stopping at a service station for fuel sooner than you expected. While you are driving in hilly terrain, if your engine begins to overheat, the engine’s horsepower-to-weight ratio is low, or it irritates you to lose a few mph in the name of saving fuel, by all means drive in Performance Mode. It confuses me to hear people advocate driving in Economy Mode only on flat ground, as there is not 1 percent difference in shift rpm between Performance and Economy modes on flat ground, except when accelerating from a stop if you use wide-open throttle. Every time you start the motorhome, the transmission is in Performance Mode. This is the default setting. If you push the mode button, it goes to Economy Mode and the light illuminates. There is no absolute number that can be given to illustrate the difference in fuel economy that will result when driving in Economy Mode. On flat ground where you will be in sixth gear no matter what mode you are in, there will be zero difference. The most significant difference in mileage will occur in rolling hills, where in Performance Mode, particularly if on cruise control, you will start up a hill in sixth gear, go to wide-open throttle in that gear, and downshift to fifth gear still at wide-open throttle, where it is using a lot more fuel. After the hill is crested, the transmission will upshift to sixth, then likely coast a little in that gear unless you are driving with the exhaust brake on. If you are, the exhaust brake will be applied and the transmission will downshift toward the preselected gear, which is generally either second gear or fourth gear. And so the process will continue, with the transmission shifting up to sixth gear on the downhill, back down to fifth gear on the uphill, etc. The problem with this is that a modern turbocharged diesel engine is much more efficient at low rpm with high throttle settings. Note: In either mode, you are free to use the up and down arrows to proactively choose the correct gear. You cannot screw anything up, even if you downshift to first gear at 70 mph. The transmission circuitry understands that you want to downshift to the next lower gear as soon as the engine rpm will not exceed the preset amount. Then it will downshift again when safe. By the same token, you can shift between Performance and Economy modes as often as you want with the transmission in any gear when you make the change. I drive in Economy Mode 99 percent of the time, including in the mountains. I use the up and down shifting arrows to choose the proper gear. I use Performance Mode only to pass another vehicle on a two-lane road, when I am willing to sacrifice a little fuel economy to gain a short-term burst of speed.

Harry, Welcome to the FMCA Forum. To clarify, the GVWR sticker in each motorhome by law does NOT state the correct PSI. It states the correct PSI if EACH AXLE IS LOADED TO ITS GAWR (Gross Axle Weight Rating). Hopefully, a coach is not at the top of its weight rating. If not, THAT is when you should go to your tire manufacturer's inflation table to determine the correct minimum PSI for your coach's actual load. Best is to use the heavier wheel position on each axle to go to the table, with all tires on an axle having the same PSI based on the heavier wheel position.

Yes, one of the times that it is very helpful to the drivetrain is when the transmission is "hunting". That is your speed/grade are a little too much in the higher gear, so the transmission is up/down/up/down shifting. You will do your drivetrain a lot of good by using the down arrow to lock the transmission in the lower gear. BTW, this applies to all vehicles, not just DP's.

Tom, I totally agree that there is no single "best" way to drive. Without the on-steering wheel control, your method would not work for our coach, as hand would be off the wheel too much of the time.

Jack, http://www.rv-chassis.com/8-bag_rideheight.html

Andy, Slight correction. Cold vis a vie tire temperature for setting PSI is NOT, repeat NOT at a given temperature. Instead, it is defined as "temperature before driving". It could be 25 degrees or 100 degrees. Going from summer temperatures to winter temperatures, you absolutely WILL need to add air to have the correct PSI. And, as you state, the tire engineers are fully aware of temperature and PSI rise with driving and that is why all their pressure recommendations are "at current temperatures before driving".

Ray, Again, monitoring both PSI and temperature is reasonably redundant. They are absolutely locked together. The ideal gas law from centuries ago (PV=nRT) is "chipped in concrete". A change in temperature of a gas WILL result in an easy to calculate (above equation) change in PSI. No question-- the temperature at the end of the valve stem is not the same as that inside the tire. But, were you to be able to know the exact temperature of the air in the tire, you would be able to mathematically compare it with the PSI reading and it WOULD be the same. Sometimes modern electronics provide us with too much information. In my opinion this is one of them.

Don, You can change gears using the up/down arrows anytime you want, and as often as you want. As far as using the engine brake (don't know whether you have an engine compression brake or exhaust brake-- the ISL could be ordered either way) along with activating the engine brake, the Allison starts downshifting toward the "pre-select" gear. That is the gear that has been programmed into the Allison. It can be any gear, but 2nd and 4th are common choices. So the transmission may already be programmed to downshift further than your selection for climbing. Yes, you can drive in economy mode anytime you wish. I use it 99% of the time. The only time I don't is if am willing to say "I will pay a lot of fuel for a little more performance". Example, passing on a two lane road. But economy mode also makes driving less "automatic", as engine temperature rises with full throttle, low RPM use. So, if a long grade causes engine temperature to rise, in economy mode, you may need to manually down arrow to a lower gear. This is what I do, and have for over 200,000 DP miles. Economy mode also follows your engine manufacturer's advice for "most economic way to climb a grade" which is just above peak torque RPM.

Don, Let's start with the good news-- the Allison ECM is idiot-proof. No matter what you do, you can not mess it up. Down arrow 6 times at 60 mph and nothing bad will happen. The Allison KNOWS that you mean when it is safe to downshift a gear at a time, do so. It will not overspeed the engine. You are (or with a little practice WILL BE) smarter than the Allison ECM. Why-- because, it is REactive-- seeing what happened behind you (and with a heavy coach, momentum dictates a good ways behind you). You can be PROactive-- seeing what is happening in front of you. You can see that you are about to top a grade, the grade is about to get steeper, etc. The up and down arrows are your friend. The most "manual" way to drive the Allison is to leave it in Economy mode all the time and use the down and up arrows to select the proper gear for the conditions you are in and the conditions you see just in front (not behind) you. Remember back to driving a manual transmission car-- whether a VW bug or all out sports car, you can decide to optimize the way your engine/transmission act. You can fine tune it, or you can let it do its own thing-- your choice.

Ray, While I have a different TPMS, let me put this in a little different perspective: Like an engine temperature gauge, I care less what the absolute reading is as long as I can (1) calibrate it with IR gun and (2) KNOW when the needle moves from that position if actual engine temperature changes. That is really all I want to know-- that the thermostatically controlled temperature is correct AND that I will know if it is not at that reading. OK, scroll forward to TPMS's. If you have verified the actual pressure with a calibrated gauge (again, calibrated gauge, as they can be off as well), I would not be too concerned that the TPMS is different by a few PSI. This assumes that PSI readings increased as you drove (as it would if you checked with a gauge). Many TPMS's do not give temperature, as temperature is 100% related to PSI (ideal gas law-- PV=nRT). Said another way, if you know/monitor PSI, temperature is not really relevant. So, if you have verified that you have the correct PSI in the tires (calibrated gauge) and that the TPMS readings change as they should as you drive (verify with your gauge) it may be doing everything you really need done. Would you like it more accurate-- probably, but it may be doing everything it needs to to keep you driving on safely inflated tires. Brett

Jack, I know that http://www.rv-chassis.com/, owned by an ex-Monaco chassis engineer has some upgrade suspension components for both 4 and 8 bag Monaco/Roadmaster suspensions.

http://www.michelinrvtires.com/michelinrv_en_us/toolbox/reference-material.jsp Click on "RV Tire Guide".

Ineagle, Welcome to the FMCA Forum. We really need to know what chassis you have to be able to offer sage advice, but yes, there are larger-diameter sway bars with much upgraded polyurethane bushings. And on gas coaches, track bars front and rear.

Smoke on start up with the 3126 could be an intake manifold heater that is not working. Pretty easy to check the heater for power when ignition is turned on and check it for resistance to make sure it is not an open circuit. It could also be improper fuel pressure causing it to run on less than all cylinders. If you have a manual primer pump, pump it. If immediately hard to pump, this is not your problem. If it pumps up and then starts easier, fuel pressure may be bleeding off while parked. The "usual suspect" is the check valve at the back of the head (front of coach) that connects to the fuel return line. Not expensive or difficult to replace.

Robsa, Anytime you need more engine braking, use the down arrow to select a lower gear. We have been on some 10+% grades in the Green Mountains of Vermont where 2nd gear was needed to keep our speed in check.