wolfe10

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.

Assume this is solid front axle-- given the chassis you have. While camber can be out, it is VERY unlikely, as it would mean that the axle is bent and has to be "straightened".

And, with all the 1200's being replaced, a large RV dealer may have a few "used" units that you can scavenge. Worth a call.

Tell us a little more about the tire wear: Both fronts wearing only on the insides? Any feathering of the surface of the rest of the tires? What brand and age tire? Miles on the tires? How many miles on the coach, and how much of this was on rough roads? Has chassis been kept lubed? You can easily check for steering component wear yourself, with a helper. Helper in driver's seat, engine OFF. Turn steering wheel back and forth through increasing arcs while you look for any play/slop from steering box to right wheel. You can also check toe-in with just basic things-- Board with nail in it to scribe a mark on the tread as you rotate the wheel with tire off the ground. Then tape measure, long stick, etc to measure from mark on left tire to mark on right tire in front of and then back side of the tire.

Yes, in most cases you have to slide the refrigerator either toward or into the inside of the motorhome to gain access. I have done several by just sliding it in about a foot and reaching down from the roof vent to access the top. That way there is no heavy lifting involved.

Sorry, never heard of them. And they are not associated with FMCA or any of its chapters in any way. Looks like a marketing group.

Jack, Best you can do is check the weather immediately before deciding on the route. This site allows you to check temperatures, weather wind conditions, etc by three hour segments: http://graphical.weather.gov/sectors/centrockies.php

Ray, In Redmond, I stopped by their booth and discussed their fan with them-- they had a fan there. I found it easy to understand that the OE fan was not particularly well designed from an efficiency standpoint and that the new one optimized air flow while lowering HP requirement.

Tip, Source Engineering (headed by an ex-Monaco chassis engineer) has them: http://www.rv-chassis.com/products.html

Mark, Another alternative is to have a coach inspection by a professional. If the basic systems (particularly chassis/driveline) are OK, it may be less expensive to forgo an extended service policy. But, I have to tell you, my view is that insurance/service policies are for things I can not afford. So, failure of an appliance, for example, would not warrant my the purchase of an expensive policy.

Deen, Good question. That would be a question for the Monaco tech hotline. And, suspect they may have to have an engineer get back to you with the answer. Monaco Oregon Service Center. ORservice@monacorv.com. 91186 N. Coburg Industrial Way Coburg, OR 97408. Mon - Fri: 7:00am - 4:00pm PT. 877-466-6226

John, Not sure how an exhaust brake could cause a squeal. Yes, if you have an exhaust leak upstream of the brake, it would cause a noise, but probably more of a "hissing" sound as the back pressure escapes. And an exhaust leak would show itself on a diesel by the deposit of black soot around the leak. The turbo should not be working-- with exhaust back pressure from exhaust brake, it would be spinning very little. Wonder if it was RPM related-- engaging the exhaust brake normally raises engine RPM. So, a belt, bearing in A/C compressor, alternator or water pump may make more noise at higher RPM and, with less noise from the engine itself (throttle closed) may be more apparent. You might try playing around with the "down arrow" on the Allison and see if it is RPM related.