New Old Truck

Is a 255 tire not supposed to be 10"?

In reply to Cousin_Eddie :

ALSO, thank you for the info if I didn't make that clear last night. If I don't end up with tubular control arms when these wear out I'll try installing those ball joints the other way around. 

In reply to Crackers :

C4's were 275's on 9" wheels stock.

Bob the REAL oil guy. said:

that is a great looking truck

It does photograph well. It's not nearly as awesome in person. 

It definitely needs more wheel/tire. I'm still thinking 18x9.5's and 285/40's.

Needs a taller tire in my eye. But, thats contrary to the intended purpose.

But, good looking truck. I dig the wheels.  

Sorry, 295/40 was the size I was looking at. that would be a 27.2" tall tire compared to hte 25" tire on the front and the 29" tires I had before. 

I mean a 255/xx/xx tire is *supposed* to have a 255mm tread face, or just over 10". 

9" seems pretty far off that IMO. 

I never did the math before. I'll be damned. 

Dusterbd13 said:

Needs a taller tire in my eye. But, thats contrary to the intended purpose.

But, good looking truck. I dig the wheels.  

Vehicles look good with wheel/wheel opening that are roughly half as tall as the vehicle. Go ahead and look at 'good looking cars' and 'ugly cars'. Wheels openings/wheels are half the height of the car on the good lookin' ones.

Crackers said:

I mean a 255/xx/xx tire is *supposed* to have a 255mm tread face, or just over 10". 

9" seems pretty far off that IMO. 

most of them seem to be closer to 8" these days, based on my recent poking around the TireRack website; mainly in R17 / R18 sizes

Well they definitely stick. I can’t really push them enough in the street to see how well but turn in is sharp and uneven pavement she’s a bit squirrelly. 

Rear end feels like it’s moving around all over the damn place. I don’t understand how it could feel this way but it definitely does. Imagine sitting on an exercise ball ..... that’s how the rear end feels. The front feels like granite. What did I do wrong back there? Are the leafs that weak?

no ideas?

Possibly. However, a set pf sliders in place if the shackles will make a dramatic change. 

what is a pf slider?

"pf" is "of" when you type a p instead of an o

ah.... how does that work? I'm guessing these are what is being referred to:

these?

There's no place to bolt these. 

Does this vehicle not have any sort of lateral locating device? (IE: pan hard rod , et all.)

In reply to Crackers :

it's a leaf spring truck, so the leafs. That's the answer to everything back there. Lateral, longitudinal, vertical.... the leafs do it. 

I'd start with a pan hard/watts link etc. 

I don't know why it would suddenly feel different unless you have a loose wheel or something obvious, but leaves can feel floaty behind like that. 

You've pulled leaves out too, haven't you? That will make it worse. 

haven't touched the leafs. They're stock as far asa I can tell, jst flipped them. The locker I think is exacerbating the problem, but I refuse to go back to one tire fires. 

Any chance you have a loose or broken perch on the axle? 

I don't know how the flip was done, or if it's possible. 

I'm pretty sure the answer is going to be some sort of additional lateral locating device though.

Locker plus new tires is probably overwhelming the leaves ability to locate the rear end. 

same tires back there as last year. I know the ubolts are tight, we just adjusted the the axle to make it straight a few weeks back. 

Considering just doing a 2 link and panhard at this point. 

Crackers said:

I mean a 255/xx/xx tire is *supposed* to have a 255mm tread face, or just over 10". 

9" seems pretty far off that IMO. 

A 255 tire is supposed to have a cross sectional width of 10 inches, not a tread width of 10 inches

Back when I knew this stuff, and 60% aspect ratio tires were wide, a 255 tire would be mounted on a wheel 70% of it's cross sectioal width (for a 255 tire this would be a wheel 7.03" wide.) On that wheel, the widest pointof the tire (not the tread width) sould measure 255mm.

Cross sectional width varies with wheel width; Tire diameter varies with wheel width.

Since this is now and I no longer know anything, the Tire and Rim Association may have modified their protocols- for instance, I believe that low profile tire (Aspect Ratio <50%) are tested on a wheel 90% of th tire section width. It's been years since I cracked the cover (see how long ago? Data was published in books with covers on them!)  of a Tire and Rim Association Handbook, so I'm probably wrong