Right on man!

 

Did you replace your spare under the bed as well? Can you go to a regular tire shop (mom & pop, Discount Tire, etc) if they are punctured or you have a problem with them?

 

I did not replace my spare. I did end up with a free spare 19.5" tire (long story) that I could take with me on a long trip I guess, but not mounted. I'm rolling the dice a bit I guess, but these are 14 ply tough, tough, new tires.

Not all places can deal with 19.5's. I used Les Schwab here locally in Washington State. They are all over the PNW in most towns and have roadside assistance too.

 

I'd round up the usual suspects; ball joints, hubs, tie rods, alignment. Tread design can cause this too, but for now ya got what ya got. Tread wear helps and 400 miles maybe is not enough yet.

 

They look sharp and the extra load rating is huge when you have that much weight in the bed. I have added these to my wish list and when it comes time to replace my Cooper ST Maxx tires I might consider dropping the extra coin for a set of 19.5's like you.

Again, the truck looks amazing with the wheels and tires.

 

Check your alignment. Tracking issues can usually be solved with a toe adjustment.

 

This was pretty much covered years ago. It is the tires. The heavy duty commercial tires are known for this on are pick ups. It doesn't hurt to check those things at all, but chances are you won't find anything that will cure it.

 

I don't have those tires but I'll go out on a limb and float a therory by you.

Your 4x4 solid axle front end came from ford with about 3.5* of caster dialed in to it. For a straight axle this is marginal, ford was was walking a fine line with the setup trying to give the truck decent road feel in the steering and acceptable tracking with the tire and suspension package they equipped them with.

If it were mine I would dial in the 5.5* of caster ( top end of factory specs ) and it should track nice and straight with those rock hard tires.

Edit, also, I've found more then a 10psi front to rear bias also loosens up the handeling more then I like. 20psi difference is likey contributing to what you are feeling.

 

I can put my 35x12.5x16.5's in and it tracks straight as an arrow! These tall skinny heavy duty tires don't have a lot of give to them. I took it out and drove it today and didn't notice much tracking at all! Maybe it is getting better with age!!

 

UPDATE.............

I have put about a thousand miles on my tires and it seems my "Tracking" issues are much better. It just took some time to burn these new tires in I guess? Just got home from another camping trip with no noticeable tracking.

I will say though, unloaded these 19.5's are not as friendly as my old 285X75X16's. Those were much smoother and had better traction say backing up my steep driveway when wet, what god made 4X4 for i'm thinkin, been using it more! I do like the feel and security of these hauling my 4k camper in the bed of my truck, worth the trade off, IMO.

 

Your not the only one I've heard say that. Maybe try a DRW one next time. That's why I stay with one.

 

I am looking to get a set of these as you can probably tell from my PM's to you and Boss.

Did you notice any difference in the driving/steering ability because of the weight difference between the tires and wheels over stock? For example, when I owned an Audi S4 we would try to get the lightest wheel and tire possible in order to free up some weight which made the car handle completely different.

Of course the 7.3 diesel truck is a completely different beast, but going from a 50 lbs tire/wheel combo to a 140 lbs tire wheel combo is quite a jump when you multiply it by 4.

I am looking to get the exact same tire and wheel setup that you are running now.

Thanks for any advice/experience you can offer.

 

Experienced this a couple years ago after upgrading to a set of E rated Toyo tires - was shocked how much different they handled from the D series we'd worn out. Heard it referred to as "radial-drift" and that pretty much described what what happening unloaded. We didn't keep the tires, ended up with BF Goodrich E series AT2s and was much happier with the handling.

 

Anybody care to explain the advantage of these over standard 265/75/16 STANDARD tires and wheels @ 80 lbs?

 

Why in the world would one put D rated tires on a Superduty?