Community Forums

shelton823 · 02-08-2023, 07:41 PM

IM BACK...Been away for a Looong time, sold our 5th wheel and are purchasing a 2004 HR Navigator 43PBQ Tag axle. I have been lurking the past couple months to re-familiarize myself with the community. I will be researching as best i can so as to not annoy anyone with repetitive questions but need to make some decisions and you guys are always the best resource.

Navigator originally came with 295/80R/22.5 according to HR. This bus currently sits on 295/75R/22.5 all around. Upon purchase I intend to replace at least 6 tires that are not quite expired but close enough.

What are my options? Assuming I should go back to factory spec 295/80s.

1) Can I rotate the 2 newest 295/75R/22.5 to the tag axle realizing they are 1.2" shorter than all the others?

2) Should I replace all 8 and sell the ones that are newer?

3) Should/can I go bigger on the front tires than even the 295/80s as I see others are doing?

4) Some better option that I am missing that you all will tell me?

Thanks all and look forward to being part of the community again.

amosnandy · 02-08-2023, 08:05 PM

The first thing I would do is go to this tire size comparison chart.

https://tiresize.com/comparison/

Determine the difference in sizes and check how much clearance you have.

I'm a believer in putting the largest recommended, especially if you can go up a level in the load range.

I'm also a believer in replacing all at the same time, even if the previous owner did not.

If you have time and energy to sell your old tires for use on a farm truck get a bunch of your money back. If they are in good shape except for the age a lot of farmers will gladly pay $100 to $150 per tire.

shelton823 · 02-08-2023, 08:14 PM

Thanks for the heads up on selling the used tires. I have used the online tool already and compared the tires (1.2" taller for the 80 vs 75). I am not near the bus for measuring purposes, to go bigger than 295/80, but appreciate your opinion to change all 8 tires. PO did a great job of rotating tires as they aged every 2 years but with this being a new to me bus want to make sure I am doing what is best. Wondered about tag axle being smaller than rest but maybe that is a moot point and I should replace all at once.

shootist · 02-08-2023, 09:10 PM

The 75 and 80 is the side wall height as a percentage of the width. In your case 295mm.
Knowing that formula you can always figure any tire height save difference in tread thickness. .80x295 236+236+565 or so for the rim is your tire height. Should be 41 inches for that tire by this formula.

shelton823 · 02-08-2023, 09:46 PM

Thank you. I apologize if I made this question sound like I needed help understanding the difference between the tire sizes. I think the main question I have relates to using the shorter sidewall/overall height tires as tag axle tires while replacing all others with original (1.2" taller) spec 295/80s. With 2 nearly new 295/75 tires on the coach I am buying, I was wondering if I could use them or if I should purchase all 8 new 295/80s.

Crasher · 02-09-2023, 07:45 AM

More importantly is the load rating. Single tire 7160# for the 295/75 vs 7830# for the 298/80. If it came with the 295/80/22.5, you would well advised to replace with the correct size for a safer ride. There's a reason that tire was OEM.

Gary RVRoamer · 02-09-2023, 12:17 PM

I'd put the best two 75's on the tag axle and get new 295/80's for drive & steer axles. The tag can be adjusted for the difference in tire height (diameter) and doesn't carry enough load to exceed the tire load rating.

As for bigger than 295, I would only do that if the load rating is marginal for the axle GAWR, or the actual axle load weight is close to the GAWR. In other words, only is the weights demand a bigger tire. A 295/80 is generally rated at 7830 lbs (single), so sufficient for a 15,600 lb steer axle. If your steer axle is likely to come near that actual loaded weight, I'd bump the fronts to 315/80 to get a 9090 weight rating instead.

vito.a · 02-09-2023, 12:43 PM

Congratulations on your new coach! These early Monaco coaches offer a lot of value.
Lots to consider here.
I think when you weigh the front you'll find you are very close, or even over the front axle load rating. This is not unusual in this time frame. A friend with a 2004 Newmar Essex is also over weight on the front.
In 2004 Monaco installed the propane and fuel tanks in the front most basement compartments. In newer years they moved the fuel tank back to the mid compartment.

I installed 315/80R22.5 front tires on our last two coaches. Monaco bumped the front tires from 295 to 315 in the newer model S series chassis coaches from the factory. I can run less tire pressure in the 315 front tires and the ride is improved.
If you decide to go this route make sure you check for interference at ride height and turn the tires from lock to lock.

You'll find the rear and tag axle are not even close to the max load rating. The original 295/80R22.5 rear tires can be run at 95-100psi and still easily meet the load requirements.
Some owners have purchased the 11R22.5 tires for the rear to save money. The 11R tire will fit the rear fine but has a lower load rating.
Let us know what you decide and how it works out?

Gary RVRoamer · 02-09-2023, 02:17 PM

As Vito suggested, I ran 11R22.5's on the rear axle of my '04 American Tradition and had weight room to spare (19,300 lbs actual). I needed the 295/80's for the front though (14,600 lb axle and about 13,500 lb actual load. Later years of American Coaches pushed or exceeded the front axle capacity and the 315's were recommended.

shelton823 · 02-09-2023, 05:31 PM

Thank you Gary and Vito, this was exactly the information I was looking for. I won’t be able to check clearance for 315s on the front before I order the tires (opposite coasts flew back yesterday) but just knowing I will pick up almost 1400# in front capacity by going back to stock 295/80 makes me feel much better. Also sounds like the 295/75 will work fine on the tag axle. Saves me $1000 and I don’t feel like I’m wasting good rubber.

Gary RVRoamer · 02-10-2023, 07:49 PM

The 11R22.5 is a widely used tire in the commercial truck world, so easier to find a replacement if you need one on the highway. Also usually priced lower - one of the local truck tire dealers where I live buys 11R22.5's by the truck load because his fleet customers buy so many. I saved almost $200/tire vs 295/80's. The 295's are pretty much a motorhome-only tire.