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Topic: Tires (Read 979 times) previous topic - next topic

Tires

Would it be advisable to replace my 275 tires with 295's?  Thank You in advance!  Jack Cuppen. 200 U320 36 ft. 
Jack Cuppen 
2000 U320 36'
Completely Renovated
2012

Re: Tires

Reply #1 –
My guess is, "no".  I looked into this for a 2001 and the opinion was that the 295s may or would rub on the air bag in hard turns.  I think they meant the metal part of the bag system. You can measure, get some idea.  As to why to do this, I thought of it only to be able to decrease just a bit the air pressure that I have to run in the 275s.

Mike
Mike
2001 U320 4010 Build 5878 (Gus)
Wrangle Unlimited Toad
Nacogdoches

Re: Tires

Reply #2 –
Hi Jack,

I have run 295/75R 22.5 Toyo and Hankook tires on my 1995 U320 and earlier 1990 Ored with no problems at all.

The 295/75R 22.5 tire is one tenth of an inch in diameter as the 275/80R 22.5 tire.

And my new $315 per tire total cost Hankook Long Haul Premium Steer tires took me to the Oregon coast and back in fine style this summer.

As Dave M says, do what makes you happy.  All the best.
Rudy Legett
2003 U320 4010 ISM 450 hp
2001 U320 4220 ISM 450 hp
1995 U320 M11 400 hp
1990 Granvilla 300 hp 3208T
Aqua Hot Service Houston and Southeast Texas

Re: Tires

Reply #3 –
@Rudy I had the 295/75R Hankook Long Haul tires installed on my 1992 U300 and I had tire rub. Had to trade them out for Roadmasters (Coopers).

If you have them traded out have them turn the wheel and check for rub while they have the front in the air. Better to find out sooner than later down the road. You can guess at how I know...

see ya
ken
The selected media item is not currently available.ken & dori hathaway & Big Agnes
🍺1992 U300 GrandVilla WTBI #4150 FOT FBP 2011
✨6V-92TA DDEC Parlor Coach 350HP Series 92
🏁2011 Nissan XTerra Pro-4X

Re: Tires

Reply #4 –
Ken,

Sorry you had to trade yours out.  Mine are thousands of miles down the road and still look new.

Guess there is a difference between the U300 and the U320 but I have no idea what that might be.

If 295/75s rub, then 275/80s ought to be real real close to rubbing.  Glad they do not.
Rudy Legett
2003 U320 4010 ISM 450 hp
2001 U320 4220 ISM 450 hp
1995 U320 M11 400 hp
1990 Granvilla 300 hp 3208T
Aqua Hot Service Houston and Southeast Texas

Re: Tires

Reply #5 –
Guys,

Occasionally I run into tires rubbing on Foretravels, even with OE size tires.

This is a VERY easy adjustment to correct.  Look at the top and bottom of the Sheppard steering box.  You will find a very small external screw (standard, not phillips).  One adjusts max left angle, one max right angle.  Screwing the screw in reduces steering angle.  If you have a bunch of clearance (which will result in poor turning radius), you can screw it out to increase turn angles.  But if you do increase turn angles, be sure to read and follow instructions for setting total angle in your axle manual.  You do NOT want the steering gear to be able to have the steering knuckle contact the mechanical stop-- things can bend if that happens.  Not complicated, but you DO need to consult your axle maintenance manual.

This adjustment is something I "fine-tune" on my coach to maximize turning angle/minimize turning radius of coach while still insuring adequate clearance between tires and coach/suspension components.

Brett
Brett Wolfe
EX: 1993 U240
Moderator, ForeForum 2001-
Moderator Diesel RV Club 2002-
Moderator, FMCA Forum 2009-2020
Chairman FMCA Technical Advisory Committee 2011-2020

Re: Tires

Reply #6 –
[Snip: "opinion was that the 295s may or would rub on the air bag in hard turns"]

I did, and they did; advise you stick with the original tire size.......
Chad & Judy
'98 U320 - Build #5315
Motorcade 16317
Wickenburg, AZ

Re: Tires

Reply #7 –
Jack, I imagine you have looked at this, but if I am reading the tables correctly, I think for H Load Range tires, and IF you get them as 295/80/22.5 versus 275/80/22.5, then the diameters are 41.3 inches versus 40.2 inches.  You should check my figures on this (I used the Michelin web site), may help you decide.  As I reported earlier, I stayed with the 275s due to likely rubbing but I did not know to adjust steering to accommodate the 295s. 
Mike
2001 U320 4010 Build 5878 (Gus)
Wrangle Unlimited Toad
Nacogdoches

Re: Tires

Reply #8 –
Brett,.

Would your steering box happen to be a M-100 as used on later years - showing that limit adjustments?

Quote
This is a VERY easy adjustment to correct. Look at the top and bottom of the Sheppard steering box. You will find a very small external screw (standard, not phillips). One adjusts max left angle, one max right angle. Screwing the screw in reduces steering angle. If you have a bunch of clearance (which will result in poor turning radius), you can screw it out to increase turn angles. But if you do increase turn angles, be sure to read and follow instructions for setting total angle in your axle manual. You do NOT want the steering gear to be able to have the steering knuckle contact the mechanical stop-- things can bend if that happens. Not complicated, but you DO need to consult your axle maintenance manual.

This adjustment is something I "fine-tune" on my coach to maximize turning angle/minimize turning radius of coach while still insuring adequate clearance between tires and coach/suspension components.>

Brett
Jim Frerichs
2002 U320 42'

Re: Tires

Reply #9 –
Mike,

You are correct in that 295/80R tires are much larger than 275/80R and 295/75R tires.

My question is regardless of brand, cost, etc. why does a tire that is 1.3 millimeters larger in radius (295/75R) not work while the one that is just 1.3 mm smaller (275/80R) work?

That difference is 0.05 inches in radius as listed on the Michelin and Hankook websites.

Hopefully one of our learned members will know because I sure don't.
Rudy Legett
2003 U320 4010 ISM 450 hp
2001 U320 4220 ISM 450 hp
1995 U320 M11 400 hp
1990 Granvilla 300 hp 3208T
Aqua Hot Service Houston and Southeast Texas

Re: Tires

Reply #10 –
Looks like the foretravel was designed around the 275/80R-22.5 Tire, and if one would like larger tires, one could take a torch or sawzall and modify to fit the desired tire you think would work best for you.
With a grinder, torch, hack saw or file, you can make anything fit.  Simple ?
Dave M

Re: Tires

Reply #11 –
Quote from: Jim Frerichs –
Brett,.

Would your steering box happen to be a M-100 as used on later years - showing that limit adjustments?

Quote
This is a VERY easy adjustment to correct. Look at the top and bottom of the Sheppard steering box. You will find a very small external screw (standard, not phillips). One adjusts max left angle, one max right angle. Screwing the screw in reduces steering angle. If you have a bunch of clearance (which will result in poor turning radius), you can screw it out to increase turn angles. But if you do increase turn angles, be sure to read and follow instructions for setting total angle in your axle manual. You do NOT want the steering gear to be able to have the steering knuckle contact the mechanical stop-- things can bend if that happens. Not complicated, but you DO need to consult your axle maintenance manual.

This adjustment is something I "fine-tune" on my coach to maximize turning angle/minimize turning radius of coach while still insuring adequate clearance between tires and coach/suspension components.>

Brett

Jim,

Yes, the Sheppard M100 is a common steering box in many high-end coaches and does have the external adjustment for turn angle.
Brett Wolfe
EX: 1993 U240
Moderator, ForeForum 2001-
Moderator Diesel RV Club 2002-
Moderator, FMCA Forum 2009-2020
Chairman FMCA Technical Advisory Committee 2011-2020

Re: Tires

Reply #12 –
Had a sidewall leak on left front tire and 6 years on the set. The others looked like they were going to join their sister at any moment so The shop that had found the leak said a Firestone 295 would work since it was the same diameter. Wrong! Traded tehm out for Contenentals of the original 275's at another outlet of the same company. They complained that they couldn't sell the Firestonre as new and I thought that was their problem for giving me bad information. Very happy with the Contenentals.
Larry
1996 U295 36'
Build # 4805
Actually we sold it but just like to lurk

Re: Tires

Reply #13 –
Just put 295 75 R22.5's on mine, much larger choice in brands to choose from, 3000 miles no problems. I do check and keep the ride height set properly, and keep the coach aligned properly. When the air is dumped completely they sit right against the bottom of the coach, but so did the 275 80R's, going to add an additional 1/2 inch on the suspension stops the cure that so if it was necessary to move the coach with the air dumped it would not be a problem. Personally I don't think it makes a difference one way or the other, I just happended to get a very good deal on a set of 295's (2300.00 out the door for 6). I had a set of Continentals on for 7 years they ran good as well.
Bruce, Linda, and Macy
Zoey RIP 1/20/19
1999 U295 40' build #5400
2017 silver Jeep Wrangler, 1260 watts of solar on top
Moving around the country

Re: Tires

Reply #14 –
bbeane, what method and materials will you be using to add the 1/2" to the stops. jc
JC
1999 U320

Re: Tires

Reply #15 –
Quote from: hotonthetrail –
bbeane, what method and materials will you be using to add the 1/2" to the stops. jc

Cut some 1/2" thick pucks from a piece of 2" solid bar stock(just what I had laying around), it takes 8, 4 on each end. I suppose you could epoxy them on top of the old stops, I'm going to weld them in place when I can get the coach down to my shop.
Bruce, Linda, and Macy
Zoey RIP 1/20/19
1999 U295 40' build #5400
2017 silver Jeep Wrangler, 1260 watts of solar on top
Moving around the country
 

Re: Tires

Reply #16 –
When our U300 had an airbag failure, it sat with the tires against the top of the wheel wells. When off pavement, fresh marks in the wheel wells can be seen. Best not to move the coach after an airbag failure unless you plug the line and can get the coach up a bit to clear the fiberglass. I could not.

Our front tires will rub the airbag end plates quite frequently but nothing more than to polish them so I never worry about it. It would eat into the bags if the plates were not there. Only happens on uneven ground with the tire up higher in the well not in normal highway driving. 295/75R 22.5 tires.

Pierce

Pierce and Gaylie Stewart
'93 U300/36 WTBI
Detroit 6V-92TA Jake
1140 watts on the roof
SBFD (ret)