Go Back   iRV2 Forums > iRV2.com COMMUNITY FORUMS > iRV2.com General Discussion
Click Here to Login
Join iRV2 Today

Mission Statement: Supporting thoughtful exchange of knowledge, values and experience among RV enthusiasts.
Reply
  This discussion is proudly sponsored by:
Please support our sponsors and let them know you heard about their products on iRV2
 
Thread Tools Search this Thread Display Modes
 
Old 05-07-2014, 03:36 PM   #1
Junior Member
 
Join Date: May 2014
Posts: 3
Question Tires and tire pressure

Just purchased a used Fleetwood Southwind. Price was right had a lot of things wrong. But there is not much I can not fix. So the hydralic levelers are now fixed, and the slide out. Rear AC repaired and the electric step. Had a few clearance lights out and the bulbs were good so that took awhile to trace circuits and repair broken wires.

The coach has 225/70-19.5 tires. They are Michelins. The tag on the door states tire pressure 65 psi. The previous owner had 115 psi in them. Road terrible with that pressure. The tire states 95 psi on them. The previous owner also had a Crossfire at 100 psi on one read dual. I replaced that with valve stem extensions with the rod in them so if something happens to the extension you do not loose air pressure. Have extensions on all tires now so they can be easily checked.

The real question is what air pressure should I be running? I know I can weigh the coach after loading it doing the front, total and rear to determine axle weight. But where to go to find the correct air pressure? Any recommendations.

Putting in the new front air bags was fun. But the old man trick of taking the AC vacum pump and getting all the air out, then putting the bags in boiling water for a few minutes to soften them up so they rolled easy made the job simple. Almost have the coach ready for the road after three weeks of work and she runs great now. To bad the previous owner did not take good care of it. But his loss was my gain. Should have a few good years in it still.
__________________

__________________
Daniel3d is offline   Reply With Quote
Join the #1 RV Forum Today - It's Totally Free!

iRV2.com RV Community - Are you about to start a new improvement on your RV or need some help with some maintenance? Do you need advice on what products to buy? Or maybe you can give others some advice? No matter where you fit in you'll find that iRV2 is a great community to join. Best of all it's totally FREE!

You are currently viewing our boards as a guest so you have limited access to our community. Please take the time to register and you will gain a lot of great new features including; the ability to participate in discussions, network with other RV owners, see fewer ads, upload photographs, create an RV blog, send private messages and so much, much more!

Old 05-07-2014, 04:29 PM   #2
Senior Member
 
Mjay's Avatar
 
Fleetwood Owners Club
Join Date: Sep 2013
Location: Southern Alberta
Posts: 112
Congratulations, and welcome to the forum. For the tire pressures, go to Michelin's website, they have a chart there for different size tires and axle loads. It will be a good starting point until you can get it weighed.
__________________

__________________
2007 Fleetwood Revolution LE 40E, 400HP C9 Cat
2015 Ford F-150 Lariat Super Crew 4X4, Blue Ox Adventa LX and Patriot braking system
2012 Polaris Rzr 800 LE
Mjay is offline   Reply With Quote
Old 05-07-2014, 05:17 PM   #3
Senior Member
 
Join Date: Dec 2013
Location: Plantation, Fl
Posts: 1,072
As was previously mentioned.
Michelin Americas Truck Tire Load & Inflation Tables
__________________
2014 Itasca Spirit 31K
2016 Mazda CX5, on an Acme tow dolly, 4 trips 5800mi
Now 2017 RWD F 150 with a drive shaft disconnect
Mich F is offline   Reply With Quote
Old 05-08-2014, 03:13 AM   #4
Senior Member
 
jadatis's Avatar
 
Join Date: Oct 2012
Posts: 247
You can calculate it with use of my made calculator.
then you need to give maximum load and needed pressure for that of tires ( yours 95 psi already given).

From car ofcource the real weighed seperate wheel(pair) weights at best, second best axle-weighing, but as long as you did not do that, we will have to do with the GAWR's front and back ( gross axle weight ratings) .
Then also give the GVWR (V for vehicle) and the speedcode of tires ( probably N for up to 140km/87m/h) to make it complete.

GVWR and GAWR's can be found on american motorhomes at the same plate as the pressure advices. Tire data on the sidewall of them.
__________________
jadatis is offline   Reply With Quote
Old 05-08-2014, 06:00 AM   #5
Senior Member
 
H. Miller's Avatar
 
Monaco Owners Club
Texas Boomers Club
Join Date: Jan 2009
Posts: 2,523
Not entirely to the subject but when were the tires manufactured (DOT date)?
__________________
Hal & Ginny Miller '04 Beaver Santiam PRT40
'04 Saturn Vue - US Gear Brake - Blue Ox tow
4"girls" (3 Irish Setters - 1 Retriever) - RIP Annie
H. Miller is offline   Reply With Quote
Old 05-08-2014, 10:12 AM   #6
Junior Member
 
Join Date: May 2014
Posts: 3
Down loaded the Michelin RV tire manuel. Will check the axle spec sheet in the coaches closet and start there. The tires had 110 psi in them when I got it. As I said the manufacture recommends 65 psi. I can start by adding to the manufacture axle load spec. Which is a dry weight and add for the 65 gallon water tank in the rear and an approximate load. That will be a good starting point. The reciept for new tires is 4 years old. The tires have over 80% tread on them. Some minor checking on the side walls from weather. Tire dealer said that was normal and not a large problem for now. Thanks for all the advise. Finally found the air cleaner buried up in front of the right front tire so need to change that out. Should be ready for the road in a few more days. Ordered the last part for the AC/Heater system and all systems will be back in top notch shape.

Thanks for all the advise.
__________________
Daniel3d is offline   Reply With Quote
Old 05-08-2014, 11:01 AM   #7
Junior Member
 
Join Date: May 2014
Posts: 3
Checked the mfg data sheet and the GAWR front is 5500 and the GAWR rear is 11,000. So the tire data psi in the coach is 65 psi which goes along with the Michelin RV Tire manuel which states Single Axle at 65 psi is 2755 x 2 would be 5510 and the duel would be 5200 x 2 for 10400. So the rears should be 75 psi which would be 5720 x 2 would be 11440. So my original thoughts of 70 psi for the front would be OK but not on the rear. So I will try 75 psi and that should work and be good for a start. I guess I get to concerned, but its all about safety. Like when I fly in a private plane. Since I used to fly I do a walk around and check everything even if the pilot does. It's my safety. Over inflated tires are just as bad as underinflated ones. They put more stress on other components in the syspension system. As well as reducing the braking efficiency because there is less tire contact on the ground. The side walls also help act as shock absorbers and when the pressure is to high it adds stress to every component like walls, ceiling shaking things loose and increasing the wear on every thing.

Once loaded I will see if I need to adjust it again. If does not take much to go from the 16500 lbs dry weight to the 20000 lbs max weight. Especially when the water tank adds almost 700 lbs if you run with it full. Add people, food, etc and it adds quickly.
__________________
Daniel3d is offline   Reply With Quote
Old 05-08-2014, 08:21 PM   #8
Junior Member
 
Join Date: May 2014
Posts: 26
Quote:
Originally Posted by Daniel3d View Post

The coach has 225/70-19.5 tires. They are Michelins. The tag on the door states tire pressure 65 psi. The previous owner had 115 psi in them. Road terrible with that pressure. The tire states 95 psi on them.
Duh

Previous owner was an idiot. You never exceed the pressure as stated on tire's sidewall. Subtract 10lbs and see how it rides and keep subtracting until you get to 65lbs which is about the lowest the tire should have in it.
__________________
Capt AL - F/V Alice's Dream - Iceland
Unimog 5000L, 220hp BlueTec, 13sp, crew cab, Michelin 445/70R24 tires - 43 Jamco LQ trailer
Pikehunter is offline   Reply With Quote
Old 05-09-2014, 05:48 AM   #9
Senior Member
 
H. Miller's Avatar
 
Monaco Owners Club
Texas Boomers Club
Join Date: Jan 2009
Posts: 2,523
"The receipt for new tires" doesn't tell you much. Several of our group have been surprised that a tire dealer would put 2-4 year old tires on their vehicle "as new". Many members also declare that a tire needs changing at 7 years of age - no matter the tread remaining or mileage.
DOT date (actual mfg. date)???
__________________
Hal & Ginny Miller '04 Beaver Santiam PRT40
'04 Saturn Vue - US Gear Brake - Blue Ox tow
4"girls" (3 Irish Setters - 1 Retriever) - RIP Annie
H. Miller is offline   Reply With Quote
Old 05-12-2014, 12:23 PM   #10
Senior Member
 
Join Date: Nov 2007
Location: somewhere in the west
Posts: 1,168
using your favorite search engine, look up "tire pressure chalk line method", and use that method, starting with the recommended tire pressure, and adjust using the chalk method.

Ed
__________________
Ed-Sommers is offline   Reply With Quote
Old 05-12-2014, 01:08 PM   #11
Senior Member
 
jadatis's Avatar
 
Join Date: Oct 2012
Posts: 247
It was a bit of a puzzle to get the maximum load of your tires out of your information, but managed it to be 3640 single and 3415 lbs dual.
at pressure of 95 psi.
Then you did not give the tag axle wich probably have the same tires, because 5500front +11000rear makes 16500lbs and not the 20000 lbs GVWR.
But not inportant cant even fill more then front and behind in my calculator.

Here the picture I made of it. Check if all the data are right and also give the GAWR of tag axle, then I will calculate for that seperately, and if they have other tires give the maxload an AT pressure.

It gives for wich weight and reserve the advice is given, so weighing might prove it to be exagerated or not.
Especially when you lift the tag all the weight is on the rear axle, if I understand right what a tag axle is.

To my estimation this is the highest pressure at wich still acceptable comfort and gripp. Another way of looking at it then the list of the tire makers wich give a minimum pressure for the load.

The 65 psi adviced is probably the AT pressure of the original tires of D-load and afterward the tires have swiched to the now using AT pressure for F load with 95 psi.
Can be I mis-interpreted your given information, then sorry and give the right data.

__________________
jadatis is offline   Reply With Quote
Old 05-13-2014, 02:16 AM   #12
Senior Member
 
jadatis's Avatar
 
Join Date: Oct 2012
Posts: 247
Reading back I saw you only mentioned the tag on the door, wich , together with the missing part of GVWR I misunderstood you had a motorhome with a tag axle.
But then still the difference between the 16500 total of axles and 20000 GVWR is not explained.
__________________
jadatis is offline   Reply With Quote
Old 05-13-2014, 07:53 AM   #13
Senior Member
 
Join Date: Dec 2013
Location: Plantation, Fl
Posts: 1,072
Quote:
Originally Posted by jadatis View Post
Reading back I saw you only mentioned the tag on the door, wich , together with the missing part of GVWR I misunderstood you had a motorhome with a tag axle.
But then still the difference between the 16500 total of axles and 20000 GVWR is not explained.
That 20,000# might be GCWR , not GVWR.
__________________
2014 Itasca Spirit 31K
2016 Mazda CX5, on an Acme tow dolly, 4 trips 5800mi
Now 2017 RWD F 150 with a drive shaft disconnect
Mich F is offline   Reply With Quote
Old 05-13-2014, 03:16 PM   #14
Senior Member
 
jadatis's Avatar
 
Join Date: Oct 2012
Posts: 247
Dont think so, 3500 lbs for a trailer would be light for a vehicle of 16500 lbs.
I think TS is seeing the 16500 lbs GAWR's together for empty weight of the vehicle. But its a bit more then the GVWR , so what the vehicle is maximum allowed to weigh. GAWR's together is mostly a bit higher the GVWR to allow some weight shifting . My camble is GVWR 15000 lbs.
so the pressure advices given are for maximum loaded vehicle, and if you are half loaded you even can do with a bit lower pressure.
Mostly the loads are more then you estimate, so weighing is the best thing to do.
__________________

__________________
jadatis is offline   Reply With Quote
Reply

Tags
tire pressure, tires



Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 
Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Similar Threads
Thread Thread Starter Forum Replies Last Post
Checking Tire Pressure narampa Class A Motorhome Discussions 17 06-10-2014 07:43 AM
Checking Tire Air Pressure - E450 s1njin Winnebago Industries Owner's Forum 10 04-24-2014 07:13 PM
Low tire pressure - need advice TodC Newmar Owner's Forum 5 03-26-2014 03:51 PM
Checking tire pressure seadogjim Class A Motorhome Discussions 14 03-19-2014 09:34 PM
Checking tire pressure on Inner tires on new Dutchstar Jeffreys Newmar Owner's Forum 6 01-25-2014 12:46 PM

» Virginia Campgrounds

Reviews provided by


Copyright 2002- Social Knowledge, LLC All Rights Reserved.

All times are GMT -6. The time now is 05:27 AM.


Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2017, vBulletin Solutions, Inc.