Thor Axis / Vegas Tire Upgrades

[T racer]

I purchased the kit from weldtec. They were great to deal with I wanted to raise the front approximately 3.5 to 4 and the rear 2 inches. We talked about new spring for the rear to raise it only 2 inches. They had springs made but when installed it raised the rear 5 inches. With the lift I also wanted to raise the gvwr . The camper comes from the factory 2 inches low in the front wanted to get it .5 to 1 inch lower in the front. The front kit worked great for the rear I used the factory rear springs added 2 leafs per springs. Installed 1 in #2 spot and the second in #4 spot . Now the springs have the gvwr I wanted and raised the rear 1 inch. Then installed a 1 inch block to get the 2 inches.replaced all the shocks with fox from weldtec.the ride is much better. The suspension is now not maxed out and has the ability to do its job rides way smoother. With the lift from the kit and the 19.5 tires I had the room for a electric step and big foot leveling kit. The leveling pistons have 8/9 inch ground clearance with a stroke of 18 inches.will post pictures in a few days. With the 19.5 tires the camper does not look lifted but it is . Sorry for the long post a lot of thought and work went into the project.

[Big-Foot]

Thanks for getting back to us with all that great info T Racer!
We’re looking forward to seeing your pics!

[pkasan]

Originally Posted by Big-Foot

I did end up replacing just the fronts for now with Toyo Commercial tires that had the 121/120 rating. The dealer here in AZ could not get the Nokian.
The handling with the heavier tire is better than with the Michelins by a pretty good margin. I had expected the heavier tire to be stiffer when traversing road seams and pot holes, but so far seem to be on par with the softer “original” tires.
I will replace the 4 rears with the same tires when I get home to Texas in a month or so.
https://www.toyotires.com/product/celsius-cargo

Your post was very helpful to me. I have ordered a set of these Toyo Celcius Cargo's for my 2017 Thor Axis. I have three questions for you please.

1) I'm curious what your wear pattern problems were prior to the tire swap. Outer Wear? Inner Wear?
2) Did uneven wear improve with the 120/121 grade tires
3) Did you also get an alignment at the same time as the tire swap?

Here is a bit more context for my question:
This is my situation. 20,000 Miles and the tread is gone on the outside half of the tires. The inside half of the tires have plenty of treads.
I'm trying to decide how much of my uneven wear was due to the soft floppy OEM tires vs. how much might be due to alignment toe in. When I originally purchased the vehicle, it was all over the road. I took it back to Thor under warranty. They did an alignment. It was still floppy on on the road. They then sent it back to Ford for replacement of steering components to correct play in the steering column. At the same time I suggested upping the toe in to increase stability. I'm not sure if they did that so the toe in may be above spec.

In the end, I found that the tires had been factory over inflated to 100 PSI. Dropping the pressure to 70 PSI resulted in a huge improvement to straight line stability. With the over inflated tires, I was likely running on a very skinny center line contact patch.

So after all those changes the straight line stability was reasonable but still a bit below my expectations. The loss of 100% of outer treads on the steering wheels is now my chief concern. But further improvement to steering stability will certainly be a welcome effect.

[2whlzstan]

I found the thread below to be helpful for understanding the Ford E450 chassis as used on class C motor homes.

https://www.forestriverforums.com/fo...el-226353.html

[Big-Foot]

Originally Posted by pkasan

Your post was very helpful to me. I have ordered a set of these Toyo Celcius Cargo's for my 2017 Thor Axis. I have three questions for you please.

1) I'm curious what your wear pattern problems were prior to the tire swap. Outer Wear? Inner Wear?
2) Did uneven wear improve with the 120/121 grade tires
3) Did you also get an alignment at the same time as the tire swap?
.

Glad it was of help to you.. My answers below -
1) outside edges of the front tires were worn badly with the worst being the right front which was worn smooth in 30k miles.
2) Roughly 3k miles on the new tires and no discernible wear.
3) I had a full 4 wheel alignment and balance job done by the same shop that did the tires. They specialize in Trucks, busses and motorhomes.

I air the tires up to the pressures on the placard by the drivers side window before every trip. 75 front / 80 rear.
Also, I have the Roadmaster sway bars, shocks and steering stabilizer installed as well as the Super Steer Trac bar (total game changer in regard to stability)

[twinboat]

Originally Posted by Big-Foot

Almost 30k and 6 years on the clock - front tires are worn and needing replaced.
I’m curious who has “upgraded” their tires to larger / wider on the front?
I’m thinking the LT225/75 R16 tires are just a little too close to their max load for my comfort level.
I will be scheduling a front end alignment and tire replacement for next week - so if you have upgraded - please let me know how it has worked out for you.
—
Also, there was a thread ((somewhere)) about a person that changed out to 19.5 wheels and tires, but I’ll be darned if I can find that thread…

You think the tires can't handle the load ( to close to their max ) but you have 30K and 6 years on them.

In my opinion, those 16 inch LT tires are tougher then any RV tire out there.

[pkasan]

Originally Posted by Big-Foot

Glad it was of help to you.. My answers below -
1) outside edges of the front tires were worn badly with the worst being the right front which was worn smooth in 30k miles.
2) Roughly 3k miles on the new tires and no discernible wear.
3) I had a full 4 wheel alignment and balance job done by the same shop that did the tires. They specialize in Trucks, busses and motorhomes.

I air the tires up to the pressures on the placard by the drivers side window before every trip. 75 front / 80 rear.
Also, I have the Roadmaster sway bars, shocks and steering stabilizer installed as well as the Super Steer Trac bar (total game changer in regard to stability)

Thankyou so much for your reply and for sharing more about what has improved your Thor Axis Steering Stability.

Kind Regards,

Paul

[Big-Foot]

Originally Posted by twinboat

You think the tires can't handle the load ( to close to their max ) but you have 30K and 6 years on them.

In my opinion, those 16 inch LT tires are tougher then any RV tire out there.

Thanks for that… You may have noticed since my original post, that I have upgraded to a heavier commercial grade tire now and am far more comfortable with them, given my loading and usage.. Most of my travel is in the south, west and desert. I don’t park the rig when it’s 115° outside. I’ll see how these tires go and may still consider upgrading to a 19.5” wheel/tire combo in the future.

[2whlzstan]

Originally Posted by twinboat

You think the tires can't handle the load ( to close to their max ) but you have 30K and 6 years on them.

In my opinion, those 16 inch LT tires are tougher then any RV tire out there.

The Toyo Celsius Cargo tires that Big-Foot installed provide greater carrying capacity than the LT tires he replaced.

The 225/75R16C Toyo tires he installed have load indices of 121 / 120, which provide maximum carrying capacities of 3,197 # / 3,086 #. The LT225/75R16 Hankook Dynapro HT RH12 tires that are installed on new Ford E450 class C motor homes have load indices of 115 / 112, which provide maximum carrying capacities of 2,679 # / 2,469 #.

At 80 psi across the four rear tires, the Hankooks provide a carrying capacity of 9,900 #. That’s a 300 # cushion over the rear GAWR of an E450 based class C. The Toyos provide 11,900 # at the same pressure. I upgraded from LT to Eurospec C tires for the peace of mind an additional 2,000 # of carrying capacity provided. We are not running heavy, but our coach is equipped with a full wall slide and I was concerned that the driver side tires were carrying more weight than they were capable of.

What I didn’t expect was the that the ride and handling would improve as well. I just did a quick internet search and find that the Eurospec Toyo tires can be bought for the same price as the Hankook LT tire.

[pkasan]

Originally Posted by Big-Foot

Glad it was of help to you.. My answers below -
1) outside edges of the front tires were worn badly with the worst being the right front which was worn smooth in 30k miles.
2) Roughly 3k miles on the new tires and no discernible wear.
3) I had a full 4 wheel alignment and balance job done by the same shop that did the tires. They specialize in Trucks, busses and motorhomes.

I air the tires up to the pressures on the placard by the drivers side window before every trip. 75 front / 80 rear.
Also, I have the Roadmaster sway bars, shocks and steering stabilizer installed as well as the Super Steer Trac bar (total game changer in regard to stability)

So I performed two of the upgrades recommended by Big-foot.
I went with
1) The front tire upgrade to Toyo Cargo Celsius Tires
2) The super Steer Sway Bar
3) 4 wheel alignment at a heavy duty Truck alignment shop -- Precision Diesel in Winchester Ontario. pdpower.ca

Due to the part cost and "covid pricing" I skipped the bigfoot recommended Super Steer Track Bar.

If you live in Quebec or Ontario, note that the best price on replacement rims and the super steer parts was what I found at Evolution tuning in Gatineau Quebec. INFO@EVOLUTIONTUNING.CA

My Results were as follows:

The vehicle straight line stability is significantly improved. It is now possible to do two finger driving.
When the wind or bumps in the road does send the vehicle off track, the effect is moderate and easy to correct with two fingers.
Previously, it was necessary to keep at least a single a full fisted grip with at least one hand in good conditions and two fists on windy days or bad roads. Prior to these recent modifications, I would always have to react swiftly and forcefully when tracking corrections were needed. So the improvement is noticeable.

I can't differentiate between how much is attributable to the tires vs the sway bar vs the alignment. Both changes were done at the same time.

However, I'm speculating that the sway bar has a lot to do with how well the vehicle now reacts to corrections. If I hit a side wind or dip in the road, then I only have to do one correction. Previously, multiple corrections were needed to work my way out of the back and forth sway of a large correction.

I also feel a lot more confident due to the increased capacity of the tires. The original tires always looked like they were about to pop. They bulged out at the sides. They always looked under inflated or on the verge of collapse.

The Toyo's look like they are more than up to the task.

When I originally purchased the vehicle, Thor had overinflated all four tires to 110 PSI. That made driving more than terrifying. It was like steering on tippytoes. It was so bad that I drove 2000 kilometers to Indiana to get the vehicle evaluated. They made a bunch of changes but did not correct the tire pressure. I figured that out after another white knuckle 2000 kilometer drive back home.

The recent alignment corrected a very significant excess toe-in. Thor likely did this at my suggestion to compensate for the profound instability. I'm not sure if this is done routinely by Thor or Ford. It may have been done simply because I asked about the possibility of better results from more toe-in. Its also possible that this is a common practice since so many Thor Axis Owners seem to rapidly loose treads off the outsides of the front tires.

So thanks again for the info from big-foot. I hope my comments and experiences are helpful to other Thor Axis owners who are seeking more steering stability, longer tire life, even tire wear and perhaps a better alignment than you get from the factory.