tireman9

x2

"Blowout" is a generic term used by the un-trained to mean the tire failed. There are two different conditions that cover probably 95% of failures. 1. Run Low Flex Failure. This is failure of tire sidewall due to operation at significant low inflation, usually due to active leak in tire or valve. This can happen in just a few miles of operation. 2, Belt/tread separation. This is a longer term (thousands of miles) of operation at improper inflation and/or speed for the load. The heat generated from this improper operation accelerates the degradation of the rubber at the belt edges which can eventually lead to separation. NOTE the operating condition at the moment of failure is seldom the cause of the failure except for impact from a large pot-hole or road debris. Damage is usually microscopic and cumulative but remember tire damage never repairs itself. the cracks only grow.

Even with 40 years experience as tire engineer and "looking at" tens of thousands of tires, I do not have X-Ray vision. That is what is needed if you want to know the real condition of your tires. Tires come apart because of physical changes in the chemical bonds between components of the tires in the internal structure of the tire. Sometimes the early signs of catastrophic failure can be discovered through X-Ray and/or Holographic examination of tires. While this type of inspection can be done it is expensive (multiple hundreds of $$) for someone to remove tires from the coach, dismount and process a tire. 10 years is a reasonable MAXIMUM age. This does not mean that all tires are fine at 9 years , 11 months and 30 days then are bad a couple days later. Some tires should be removed at 7 years but it is hard to be 100% certain they will be OK 3 years later. In my professional opinion I would replace the 10 year old tires at once. ( I like KPSmith's suggestion of 15 mph max)

Brett is correct. 1. New tires must be able of supporting the same or higher load than your 9R-22.5 LR-F 4540# @ 105 psi SIngle 4300 Dual 2. I assume Dual rears Be sure to confirm "Minimum dual space" spec on new tires. Spec on 9R-22.5 is 10.3 3 9R was approved on 6.0, 6.75 & 7.0 rim width so you need to confirm which you have.

First you need to more clearly identify the problem. Vibration through steering wheel or through floor in front? Both driver & passenger floor vibrating or just one side. Is the vibration felt at rear of coach? When did you first notice the vibration Second you need to be sure you have identified the actual cause of the problem. Is the tire at the location of the vibration withing established tolerance for run-out? I have seen demonstration of balancing a cinder block so problem may not be balance Have you confirmed tires are fully seated and concentric on the wheel? Have you confirmed the wheel is properly centered on the hub? With a large center hole I assume your wheels are "lug-centric' so it is more important that the nuts are tightened in steps and in sequence.

Ray Neither Brett nor I nor others are saying ignore the sentence you seem to focus on. What we are suggesting is to consider the entire set of instructions from the tire companies. If you know for a fact you have no tire in overload you are more than OK to run the inflation shown on the tire placard. That inflation is based on the assumption you are running your axles at GAWR. If you would like a bit better ride then you might consider following the section in the tire companies current detailed instructions and consult the charts. and ensure you always have no less than the minimum inflation shown. I suggest you do an even better job and set your TPMS low pressure warning level at the minimum pressure needed to support the heaviest end of that axle. You set your CIP to the minimum +10% and set the high pressure warning on the TPMS to the CIP + 25%. I would consider the best all around solution to the question of what pressure to run. or if you prefer just follow the Placard. Your choice. Any chance you will be at Indy. If so I suggest you attend one or both of my tire seminars.

Can you provide the specific design name of your Toyo tires?

You say it showed +50 psi when parked. While heat soak from hot brakes can warm a tire, that sounds a bit excessive. There wasn't another RV parked nearby by any chance? RE TPMS I bought Tire Traker TT500 system. I like the Lifetime Warranty, the ability to program my own warning levels and the cool "Morning Reset" mode to allow me to get cold inflation readings in the AM without having to get outside the RV. I will be at Indy if anyone wants to see my system. Send me a message so we can connect.

To all who replied: Well I did finally pay attention to the combined knowledge of the group here. I have a DPDT switch that selects Shore Power or RV inverter power. The Inverter is wired to a relay that gets it's power through a lighted switch to the Ignition so I can't drain the coach battery by running the inverter. I will be at Indy Monday late afternoon till Sat Noon after my last Seminar. Drop me a message if you are interested in seeing the install and leave your contact info so I can call you. I am scheduled to give 6 seminars so have a rather full schedule of Genealogy and Tire seminars. (at least I know those topics

According to the schematic my Refrig is wired directly to the 110v line that runs to the shore power plug. No Inverter was provided by Coachmen I have no 110v AC if I am not plugged into shore power. Short term (on trip to Indy) I will shut off breaker at power center to isolate refrig 110v circuit. Then when others can look at what i have at Indy we can decide best next step. We never run anything on 110v when driving.

RE back-feed. I did not think that if I applied 110v to the output side of a AC>DC converter it would act like a DC > AC Inverter. I picked up a DPDT switch. Am looking for ways to run cords to various devices. Not a lot of room in my Class-C

I am having problems changing my Profile. Right now the "Travel" item requires the selection of "with children" or "with pets" or "Full time". We do not travel with children or pets nor do we travel full time.

Coach did not come with an inverter. Only a standard converter. I am in a small Class-C so don't have the bells & whistles all you big class-a folks have.

Agree but didn't find any fully automatic system. Also didn't find DPDT switch but figure it should be OK as long as I disconnect the 110v system when the chassis engine is off.

No ice maker. I understand that it is possible to run on propane. Issue I have is that if there were an accident having the propane "on" can be a big problem. (See Mac the Fire Guy) Now some / many might not feel this is a serious concern and I understand accept that position. I may even be irrational in this concern but feel it is possible to keep the food cold enough to keep the DW happy using the 12 v system from my engine. Coach has no on-board inverter from Coachmen.

I understand the goal of having only one power source at a time. In My Class-C I only have 110V in the coach when plugged into shore power. Not sure if I understand the "backfeed" or "closed-Loop" unless I were to keep engine running (inverter active) and also plug in the shore power. I am installing a double poll switch that will isolate the inverter from the 110v system. Switch is accessible near control panel right inside my entry door. Ross and others, I will be at Indy. I should be in Governing Board / Committee 30 amp lot unless I burn to the ground on my drive from Akron to Indy Aim to arrive on 10th late afternoon. Can give "free tours" of my rv on 11th

Still have absorption fridge. I'm in a Class-C. The OE fridge works fine. I would just like to shut off the propane when driving.

I would like to not have to plug & unplug the refrig every time I connect to shore power. That plug is only acessable through the outside refrig vent door.

Got DPST so end up with on/off of the output of the Inverter. This accomplishes same as just completely removing the extension cord between output of inverter and the outlet that connects to the Refrig.

Brett Can do. Didn't think about the 110V side as I had no problems with prior install but I would prefer to do things in a safer manner. Off to Lowes electric dept.

Brett, Is the problem having 110V from shore power connected to the output side of the inverter? Is this a problem even with the inverter isolated from 12V? If I isolate the Inverted form O2 by either unplugging the "extension" or installing a relay switch you are saying it would be OK?

In my previous coach I installed a 750W inverter to power the 110v side of my absorption RV refrigerator. I power the inverter through a relay that only draws 12V DC from coach battery to the inverter when my engine alternator is running so I'm not going to kill the battery. This system worked fine. Kept food cold for a trip from Ohio to Oregon and back while driving about 6 hrs a day, Installing similar in current Class-C and have a connection I am pretty confident in but wanted another person to look at. In the attached simple schematic O1 is the outlet the fridge is plugged into and is located in the fridge "closet". O2 is an outlet in the space where a outside TV would be installed but I don't have a TV so the outlet is not used. I am installing the inverter in this empty space. According to schematic from Coachmen both these outlets O1 & O2 are on on same 110v circuit which is hot when shore power is connected to the coach. The 110v heating element in the Dometic fridge is rated 350 watts The inverter 12V + is connected to the continuous duty relay which connects through a 30A fuse to the coach battery, The relay is activated only when the ign switch is on. My question is.. If I make a male to male extension cord and connect the inverter to the O2 outlet will it work? Getting to the back of the outlets makes a lot more work, The extension cord seems too simple but I figure that as long as I wire the extension cord correctly to the 3 prong plugs it should work. Not to "code" but I think it is electrically safe. Comments?

Rayin. I already answered your post on adjusting tire inflation in the TIRES forum. The information will not change simply by asking the same question in this thread. For those that want the answer, here is direct quote from Goodyear " Since RVs can be loaded with many different configurations, the load on each tire will vary. For this reason, actual air pressure required should be determined based on the load on each individual tire. Inflation pressure should be adjusted to handle the tire carrying the heaviest load, and all tires on the axle should be adjusted to this standard. " I think the key part of the GY advice is the warning you are referring to is that you should inflate to the pressure needed to support the load conditions. The section you pulled that statement from was warning for people that simply lower pressure in an effort to get a better ride. I suggest you re-read ALL the information on the reference GY page. As I also pointed out in the TIRES thread similar information on how to weigh an RV and adjust tire inflation based on scale numbers is also provided by Michelin and Bridgestone. FYI true "blowouts" occur when a tire looses most of its air not when it is a few psi low. Being a few psi low can lead to belt separation after many thousands of miles operation. The federal tire placard numbers are as you know based on the GAWR not the actual loads. If you have loaded your RV to the GAWR then yes you must run the stated inflation

If you check the DOT serial you can see who made Dynatrac HERE

Rayin, I would be comfortable with suggesting lower than placard inflation IF I am talking with an RV owner that is making an effort to properly care for their tires. Info on placards is based on an assumption that the vehicle owner is not aware or interested in getting a better balance of performance and durability. Those inflations are assuming two things. First that the RV owner will not ever get on a scale and Second will never overload either axle of the RV. The problem is that RVSEF, who does 4 corner weights and provides inflation info at FMCA events, that has the data that shows that over half of the RVs on the road probably have at least one tire or axle in overload so the Second assumption about placard numbers is not supported by reality. RE tire company suggestions. While there are probably documents suggesting to inflate to placard pressure, I think Brett is correct in the idea that such info is written by the lawyers to protect the RV company when the owner fails to do proper maintenance of the RV tires. Lets look at what a couple tire companies offer for advice and information. Goodyear has an RV specific web site with information on how to weigh an RV and adjust tire pressure Michelin provides similar information Even Bridgestone tire Co that does not actively market to the RV community offers info on how to weigh and then set inflation Now there may be some small importer that has no engineering staff that wants to avoid having to answer technical questions that decided it is easiest to tell people to just follow the placard. This is not wrong but just no optimal advice. Then there are couple actual tire engineers, like myself, who monitor RV forums and attempt to provide even more detailed info to the small percentage of owners that want the details. But as I said to my knowledge there are only two of us on line and I may be the only one monitoring FMCA forum.