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Main Forum => General Discussion => Topic started by: JoeyD on February 04, 2013, 10:04:20 pm



Title: Tire Pressure
Post by: JoeyD on February 04, 2013, 10:04:20 pm
I did a search regarding tire pressure and though quite helpful, I couldn't find specific data concerning my 2910T.  After having a tire replaced do to a road hazard, the tire adjusted my tire pressure to 90 in the back and 80 in the front.  After leaving, I found the ride to be quite "hard".  What would be the proper inflation for the 2910 w/triple slide?
Thanks again everyone.


Title: Re: Tire Pressure
Post by: ragoodsp on February 05, 2013, 09:03:04 am
joeyD:

On my 3100 I run 72 lbs. in the rear and 68 lbs in the front.  The coach handles very well and the ride is not as harsh as it is with the 80 plus pounds of pressure.  I had the coach on the scales and then went to Michelin's charts to come up with those inflations.  I only have one slide so you might be  coming in a few hundred pounds over me and the inflations should be a little more but I think 90 lbs in the  is way to much and over max for the tires and you will really get that wandering feeling in the front end.   best of luck.   Ron


Title: Re: Tire Pressure
Post by: Barry-Sue on February 05, 2013, 09:27:53 am
JoeyD

The tires (LT225/75R16) on our 2012 2551 are rated for a max inflation pressure of only 80 pounds and we run 72 pounds front and rear.  Not sure if PC uses a different tire on the 2910's.  Also, max pressure is printed on the side of each tire.

Barry


Title: Re: Tire Pressure
Post by: dickreid1 on February 05, 2013, 08:29:49 pm
Joey D

I weighed my 2910D and according to the Michelin chart set the front tires to 75# and rear duals to 80#.

Dick


Title: Re: Tire Pressure
Post by: JoeyD on February 05, 2013, 08:49:02 pm
Thanks everyone, you folks are the best.  I'll knock my mine down to 75 front and 80 rears.


Title: Re: Tire Pressure
Post by: ron.dittmer on February 06, 2013, 12:37:13 am
JoeyD,

Assuming you have the same tires as most PC owners do, the max tire pressure as stated on the tires is 80 psi.  You don't want to exceed 80 psi.

PC-USA places a sticker on the driver door frame that states what the tire pressure should be for your particular model PC.

On my 2007 PC-2350, the sticker says 60 psi for the rear tires, and 65 psi for the front tires.  But I add an extra 5 psi all around because my tires visually look a little under-inflated and also to save a little gas.  But more air = harder ride.  I once tried 80 psi all around and the rig hit every crack in the road real hard.  Needless to say, at our first stop I let out some air.

I keep procrastinating, but I should weigh my rig while on a trip and find out from the tire manufacture's website what the tire pressure really should be.

Oops...I see I have repeated much of what others have said.  Then you heard it twice or thrice.


Title: Re: Tire Pressure
Post by: BarbRN on June 11, 2013, 09:47:12 am
So, after much discussion in our house, what dictates the tire pressure?  Tire manufacturer, chassis manufacturer or motorhome designer?

 (WH)

Seems to me it varies depending on the load and which model is on the chassis and where the weight is distributed with each build.  But then, I'm only a girl. 


Title: Re: Tire Pressure
Post by: Shipper on June 11, 2013, 10:10:18 am
So, after much discussion in our house, what dictates the tire pressure?  Tire manufacturer, chassis manufacturer or motorhome designer?

 (WH)

Seems to me it varies depending on the load and which model is on the chassis and where the weight is distributed with each build.  But then, I'm only a girl. 

The weight of the coach loaded dictates tire pressure restricted by the maximum setting per the tire manufacture. The chassis manufacturer has nothing to do with the tire pressure once the chassis has been modified, but the MH manufacturer may have a suggestion restricted by the previous sentence. JMHO.


Title: Re: Tire Pressure
Post by: TomHanlon on June 11, 2013, 11:14:58 am
So, after much discussion in our house, what dictates the tire pressure?  Tire manufacturer, chassis manufacturer or motorhome designer?

 (WH)

Seems to me it varies depending on the load and which model is on the chassis and where the weight is distributed with each build.  But then, I'm only a girl. 

It is up to the chassis manufacture to set the pay load based on a number of things like wheels, axles, brakes, fame etc. It is up to the motorhome maker to stay within these limits. The tire manufacture puts the maxmium air pressure for the tires. This is why a four wheel weight is important.

"But then, I'm only a girl". If i was trying to be funny, I would say something about the amount of air given off by the different sexes, but I would never say something like that. Oh, no.


Title: Re: Tire Pressure
Post by: BarbRN on June 11, 2013, 12:24:07 pm
So, after much discussion in our house, what dictates the tire pressure?  Tire manufacturer, chassis manufacturer or motorhome designer?

 (WH)

Seems to me it varies depending on the load and which model is on the chassis and where the weight is distributed with each build.  But then, I'm only a girl.  

It is up to the chassis manufacture to set the pay load based on a number of things like wheels, axles, brakes, fame etc. It is up to the motorhome maker to stay within these limits. The tire manufacture puts the maxmium air pressure for the tires. This is why a four wheel weight is important.

"But then, I'm only a girl". If i was trying to be funny, I would say something about the amount of air given off by the different sexes, but I would never say something like that. Oh, no.

You implied it, enough for me to remember your name! (nod) roflol

Air comes from various places don't forget!


Title: Re: Tire Pressure
Post by: TomHanlon on June 11, 2013, 03:00:15 pm
I have nothing more to say about that and that's that.  >:(.... >:(.... >:(


Title: Re: Tire Pressure
Post by: jampodd on June 11, 2013, 03:30:03 pm
I just had my 2552 weight and they recommended air pressures. Weights were LF 2160, RF 2100, LR 3820, RR 3780. Total weight 11,800, no water in tanks. Recommended pressure were 65 all around, Although I keep slight over 70 in all and it handles and rides fine. I also had new sway bars, trac bar, sumo springs and shocks put on.


Title: Re: Tire Pressure
Post by: ragoodsp on June 12, 2013, 09:00:41 am
jampodd:

Your four corner info is great and very valuable.  I am impressed that PC has done such a good job of balancing things out so well front to rear and side to side.  i am sure a full water tank will change things some. I would say 70 lbs would be perfect for your coach.  Now I know why my 2551S never handled exactly the way  I would have liked it to....I was running way to much air at 75 and 80lbs!  Thanks, Ron


Title: Re: Tire Pressure
Post by: ron.dittmer on June 12, 2013, 09:57:49 am
This discussion reminds me of my uncle who years ago bought an E250 maxi-cargo van for camping in.  He said the psi rating on the tires were 55 so he put in 55.  He eventually figured out that his load never called for such high psi.  At home it was around 30 and on trips he added I think 10 psi more.

BTW:  He still has that 1996 E250 maxi-cargo van, and it could pass as a new old-stock van.  You could perform surgury in it today.  He even keeps it up with wax and all.  Cargo vans typically get beat up starting on the first work day. 


Title: Re: Tire Pressure
Post by: Sparky on June 12, 2013, 10:10:53 am
GOOD THREAD and a never ending argument. Many good points, main point never never underinflate and never over inflate,,, would be interesting to see the PSI on your tires after rolling a couple 100 miles in the heat and running at 80psi, wow,,,, I think every rig obviously is different depending upon size, suspension and loaded not loaded. If you wanted to be anal about it you would adjust the psi every time filled up with gas, used your water tank etc etc,,, too much work for me,,, I do check my air every day when traveling. I adjust couple of psi if going dry camping and vice versa more/less weight.  Another point,,, altitude.. thinner air above sea level,, I do adjust when I'm running around the mountains for a few days.

WATER TANK-??? I think most of us have the 55gallon tank in the rear.. looking at mind, it looks like it extends the whole width of the rear, so that as it empties the weight is evenly distributed on both sides of the rear tires. Now if your straight dumping with hook ups no problem all the weight is gone, however if your dry camping it seems the tanks are mainly on the driver side rear,, so you have now put a lot of extra weight on one side, considering 400lbs  might need to up the psi on the rear driver side a little, especially if not dumping too soon.. Just curious
David Sparks
2008 PC 2350
Houston


Title: Re: Tire Pressure
Post by: ron.dittmer on June 12, 2013, 10:29:22 am
I do have a question on tire pressure.  Maybe it was already discussed, but is a lot to read through.

If one corner is heavier than the other adjacent corner, would you have different psi for each corner?  Or do they recommend putting the same psi per front pair and same psi for all rear tires?  I know the fronts are most sensitive to unmatched psi.


Title: Re: Tire Pressure
Post by: Barry-Sue on June 12, 2013, 10:36:35 am
Ron

Each tire on an axle must have the same pressure.

Barry


Title: Re: Tire Pressure
Post by: TomHanlon on June 12, 2013, 10:48:51 am
When I had a 2010 model 2350 the fresh water tank was under the bed at the rear, passengers side. The gray tank was under the fresh water tank also on the passengers side. The black tank was on the drivers side. On my 2012 model 2552 the black and gray tanks are switched as the toilet has moved from the drivers side to the passengers side of the center line. The toilet has to be over the tank used as the black tank. The fresh water is mid way under the passsengers side bed.
If you look at all the layouts you will see the black tank changes by where the toilet is located. You can tell this by looking at the capacity of each tank. PC only uses two tanks, the one 35 gal. that fits under the passengers side behind the axle and a smaller 23 gal. tank the fits under the sani-con on the drivers side. The fresh water tank changes size based on the layout.


Title: Re: Tire Pressure
Post by: ron.dittmer on June 12, 2013, 11:01:43 am
Ron, Each tire on an axle must have the same pressure.  Barry
That's what I figured.  Thanks Barry.

So whatever the highest psi is needed on any one rear corner, all for rear tires get that same high psi regardless.  2o2


Title: Re: Tire Pressure
Post by: ron.dittmer on June 12, 2013, 11:08:05 am
When I had a 2010 model 2350 the fresh water tank was under the bed at the rear, passengers side. The gray tank was under the fresh water tank also on the passengers side. The black tank was on the drivers side. On my 2012 model 2552 the black and gray tanks are switched as the toilet has moved from the drivers side to the passengers side of the center line. The toilet has to be over the tank used as the black tank. The fresh water is mid way under the passsengers side bed.
If you look at all the layouts you will see the black tank changes by where the toilet is located. You can tell this by looking at the capacity of each tank. PC only uses two tanks, the one 35 gal. that fits under the passengers side behind the axle and a smaller 23 gal. tank the fits under the sani-con on the drivers side. The fresh water tank changes size based on the layout.
Yes indeed.  Good explanation Tom.

With our 2350, most of the fresh water ends up in the gray tank below it.  At least the weight doesn't shift around much with water usage.


Title: Re: Tire Pressure
Post by: ragoodsp on June 12, 2013, 12:27:00 pm
Ron D.:

I called Michelin on that very question and they had a very quick answer....take the heaviest corner and inflate both tires (double if rear) to that PSI.   Thanks


Title: Re: Tire Pressure
Post by: ron.dittmer on June 12, 2013, 01:01:05 pm
Ron D.: I called Michelin on that very question and they had a very quick answer....take the heaviest corner and inflate both tires (double if rear) to that PSI.   Thanks
Thanks for the confirmation.

So it is "Essential" to get each corner weighed, not the axle.

Can a truck stop scale weigh individual corners?  Where does one go to get this done?


Title: Re: Tire Pressure
Post by: gl1500 on June 12, 2013, 01:33:50 pm
Ron,
   You need to find an outfit that does a complete RV evaluation, including driving and handling.  We took ours to Henderson's in Grants Pass, Oregon.  They did a complete road performance assessment.  After driving, they returned and did a weight check of each individual tire.  Came up with LF 2300, RF 2100, LR 3850, RR 4150 and LS 6150, RS 6250 and total front 4400 and total rear 8000.  Manufactures front is 5000 and rear is 9500.  They recommended front and rear tire pressure of 70 psi.  This was on our E-450.  They also did an alignment check as it was way off.  We added  front and rear anti-sway bars, rear trac-bar and a steering stabilizer.  Made a world of difference. 
   Just for info,
       Bob


Title: Re: Tire Pressure
Post by: ragoodsp on June 12, 2013, 02:10:31 pm
Ron:

Cat Scales (trade name) are found at most truck stops and they only weigh  "by the axle".  Here in NH the Dept of Motor vehicle do random mobile truck safety clinics/stops and they utilize the individual wheel scales but they are not overly open to doing anyone a favor I have been told.  Not sure what I am going to do to be honest.  Perhaps big spring/chassis truck repair shops offer such a service?  Good luck, Ron G.


Title: Re: Tire Pressure
Post by: jampodd on June 13, 2013, 09:42:21 am
Bob,
I did the same thing, although I took mine to Mainline Truck and Trailer in Bedford, Ohio. They were trained and recommended by Henderson. Handling was good before changes but improved after. I feel it was money was spend.

Jim


Title: Re: Tire Pressure
Post by: Sparky on June 13, 2013, 09:02:02 pm
I  think we have the air pressure question answered.. do not over/under inflate,  same PSI on each set front and rear, PSI will vary between each different RV,   Same area new issue

ALIGNMENT  I have seen people get new tires, get alignment and leave it alone as long as tires behave and driving is good..  I rotated tires on a previous RV, had 7500miles on it, tires looked great,, 4000 miles later ate one of my tires on the front..  My PC  had 6700 when purchased, has stabilizer and shock system on it after market. Drives wonderful, am approaching 12000 miles, tires still look great,  based upon previous post and comments I am not going to touch the tires (alignment/rotation) just keep checking and rechecking tire pressure haha,,,, I do plan on getting about two years more on the tires,, mileage will not be the problem, age will be the factor.   Any thoughts on rotating tires. I will do an alignment when buying new tires
David Sparks
2008 PC 2350
Houston


Title: Re: Tire Pressure
Post by: ron.dittmer on June 13, 2013, 11:22:06 pm
I cannot recommend rotating tires at all on any 6 tire motor home.

But if you are determined, then I recommend swapping front tires with eachother, and rear pairs with eachother.  Never split pairs of rear tires and never switch inner tires with outer tires because their diameters have worn down to different dimensions.  If switched, the larger diameter tire will be weighted heavier, ripe for a blow-out.

It seems everyone is replacing tires because of age, not tire wear.  Let them wear as they do and let the load be distributed naturally even on them.  You'll be replacing them because of side wall cracks long before the threads are worn.

Motor homes are not cars.  Different rules apply.  That's the way I see it anyway.  Give me a "disagree" and lower my Helpful Rating if you must.


Title: Re: Tire Pressure
Post by: Sparky on June 14, 2013, 09:01:45 am
Ron
  No I do not disagree,, just looking and seeing what other peoples thoughts are.  These are very expensive vehicles and as some of us know if we take care of them they will last a long time and provide us with a lot of joy. Some people  shop for an answer to a question sometimes,,, I like to see different opinions and then make a decision.  Currently I am going with no tire rotation, alignment with new tires,, just reinforcing  my  decision,,  If 6 people jumped in here and said they rotate their tires the I might reconsider    BTW,,, I keep looking at my garage and dream of taking out about  4 ft so I can park my cruiser in it haha
David Sparks


Title: Re: Tire Pressure
Post by: ragoodsp on June 14, 2013, 02:15:41 pm
No rotation here!  If they are going round and round with no bumps or thumps I leave them alone!  Many vehicle makers s including BMW are not reccomending any rotation if all looks good.   Thanks, Ron


Title: Re: Tire Pressure
Post by: lghjr on June 14, 2013, 02:28:26 pm
Agreed - wear them out in place, replace as pairs or fours, fronts together and 4 rears together (easier on the differential).


Title: Re: Tire Pressure
Post by: keelhauler on June 15, 2013, 10:07:46 am
Were you aware that Ford will check the alignment for free on your new MH. Call the 800 number that came with your RV to find a dealer that works on MH's. They will setup an appointment for you.
They found my new 2552 slightly out and adjusted it under the warranty.  (cheer)


Title: Re: Tire Pressure
Post by: ragoodsp on June 17, 2013, 09:41:59 am
Keelhauler:

You must have gotten a Ford Service rep on a good day!   I spoke with them at length 2 years ago pertaining to the front end alignment on my 2011 2551S, they flat out refused to pick the tab up and said it was the responsibility of the RV manafacturer and not Ford.  I went to a truck center (no Ford dealer could do it in NH) and had it done and submitted the $120 bill to them with a nice form letter and they again turned me down!  Perhaps they have changed their policy of late and they should have!   Thanks, Ron


Title: Re: Tire Pressure
Post by: ron.dittmer on June 17, 2013, 11:16:40 am
I realize that the various PC models have different alignment issues....some maybe with little to none.  But our PC2350 required offset bushings to get the alignment done right.  This involves some disassembly/reassembly.  It's more than considered typical.

Here is what offset bushings look like.  In the picture, the left gold one is slightly off center, the right silver is more extreme.  A "Good" truck alignment shop will know what to do if they cannot align the rig working with the stock suspension.  Such an alignment is not something a generic tire shop can do, and maybe not for some Ford dealers.  I fear some shops adjust it as far as they can then consider it done....good enough.

(http://shop.advanceautoparts.com/wcsstore/CVWEB/staticproductimage//617/full/21880321_moo_k100008_pri_detl.jpg)


Title: Re: Tire Pressure
Post by: Denny & Barb on June 17, 2013, 05:56:43 pm
Ron I had to do The same and add offset caster bushing to get my rig to handle.
see link below  for story.

http://www.phoenixusarv.com/community/index.php/topic,1352.msg10056.html#msg10056


Title: Re: Tire Pressure
Post by: ron.dittmer on June 18, 2013, 07:56:29 am
The trend seems to be that models 2100, 2350, and 2400 require offset bushings.  Not the 2551 on up.  The short wheel base with a long rear overhang is most influential.  The front end rises a bit which then requires those bushings for a proper alignment.