Originally Posted by Vince and Charlette
Tried it all on my 2015 GT 364TS with only moderate results:track bar, front and rear Roadmaster anti-sway bars, steering stabilizer and CHF. The dealer undid the CHF because it made the OEM sway bar strike the frame. Still having to make constant steering input. Staring farther down the road helps a bit. Don't know if it makes much difference, but the early 2015s came with 19.5 inch wheels.
I do not fully buy in to the 40/60 rule. I want everybody to be absolutely clear that I do not doubt the Ford engineers statement, I just have trouble reconciling it.
Lets start with an Top 10 Automotive Mechanical Myths and Misconceptions
concerning 50/50 weight distribution:
"4. Myth: The "ideal" weight distribution is 50/50: The vehicle has the same weight on both the front and rear axles.Truth: While most sport-oriented cars do have weight distributions close to 50/50, there's much more to proper handling than just distribution. A car with 50/50 weight distribution would handle poorly if most of the weight was at the ends of the car (i.e., ahead of the front axle and behind the rear axle).
Far more important than weight distribution is the location of the center of gravity and polar moment of inertia. (The center of gravity is where a giant could balance the car on one finger. Polar moment of inertia refers to whether the vehicle's weight is concentrated in one location — which makes for a responsive car — or spread throughout the vehicle.) Something else against 50/50 being the ideal weight distribution: Most open-wheel Formula-style racecars, which many people would hold up as being the best-handling type of racecars, have 60 percent or more of their weight on the rear tires."
Secondly, I would add that the F53 is used for a variety of package delivery applications and I have no idea how an engineer could expect a 40 / 60 weight distribution when loading and unloading packages.
Thirdly manufacturers today are recommending that you restore the front axles weight when using a weight distribution system. This means that in order for steering to be safe and effective, you need to make sure the front axle has at least the same amount of weight when hitched, as it did before it was hitched. I have a lot of experience with this from my previous bumper pull trailer.
Now you may correctly say that this has little to do with a Class A rig and you would be absolutely right. My point is that the 40/60 rule seems a little arbitrary and potentially irrelevant as long as your front axle has not been lightened in such a way as to affect steering performance and you have not significantly affected the polar moment of inertia.
I personally believe perfect balance is having the same percentage of axle capacity being used on each axle. Frankly a rear tag axle will always have much more capacity than the front. When I did this calculation I came up with the following:
Weight: 6,786 LBS
Axle GVWR: 8,000 LBS
% of GVWR 84.8% of capacity
Weight: 12,125 LBS
Axle GVWR: 15,000 LBS
% of GVWR 80.8% of capacity
Actual bias for reference:
If you look at % of GVWR I am only 4% off and when you look at actual weights, I am 10% off, meaning I have to move 5% forward, which will probably happen when I load my gear. Personally, I don't really think this will affect or improve anything. I will try to calculate the polar moment of inertia and follow up.
I am not trying to start a huge debate here, I am just saying that I personally believe the 40/60 rule is not nuanced enough to be a hard and fast rule.
To finally try to answer your question:
I am very surprised you have wandering, especially with a steering stabilizer and all the upgrades you have done. I would suspect the wheel size MAY have something to do with that but I would love to hear from someone who upgraded the bigger tires and report back on the improvements, if any.
The really big question though is what amount of wandering is normal for an optimized rig. Did you see any improvement with all the upgrades you made? Do you drive on worn or bad roads that pull your rig this way and that? Do you frequently experience winds?
There are many factors to consider.