RE: #-Ply vs. Radial Tires & Handling

[Jim Grammer <jimg@domain.elided>]

>My '58 A-102 has a tendancy to easily get pulled side to side while 
cruising
>down the road, especially if the road is uneven at all.   The difficult
>handling is, of couse, compounded by the manual steering.   My uncle
>suggested I invest in some good radial tires - that these will handle the
>road A LOT better than the ply tires I currently have - 4ply in the front,
>6ply in the rear. (Left over from Grandpa - who only ever drove it around 
his
>farm - into town only on occasion)
>
>Anyway, I wanted opinions before I invest the money. (I'm on a tight 
budget,
>you know)   The ply tires on it now are in good shape.. but the handling
>isn't all that great.   Will radials really improve it $That much?


Jeffrey -

This is highly entertaining to me, not because I'm making fun of you or 
your truck(remember, I drive a B pickup 72 miles every work day), but 
because you're going through exactly the same list of questions that I went 
through while getting the B up and running.

You're right, the bias ply tires will tend to follow any irregularity in 
the road, especially seams and such that go more or less in the direction 
of travel. I don't even want to recall my memories of 7.00x15 bias plys on 
the rain grooved freeways of the L.A. area(my first T-all and another 
lifetime). The situation is compounded by kingpin wear , loose tie rod 
ends, wimpy shocks and the 'famous' Ross roller stud steering boxes.

As an aside, the Ross boxes use a tapered stud that rides in the spiral 
groove on the steering shaft(which is one piece from the steering wheel to 
the box). The tapered stud(or studs, some use 2) mounts in the sector shaft 
with roller bearings that are preloaded so that the stud has no lateral 
play but can just barely rotate as the stud rides in the groove. Typically, 
the stud ceases to turn at some point due to wear, damage, or maintenance 
neglect. Once the stud stops turning, a flat spot wears in the side of the 
hardfaced stud. Now your steering has slop that you can't adjust out. When 
you pull the old beast out of storage and change the steering box fluid, 
you free up the stud(maybe) and now you have some spots that feel right and 
some that are loose as the flat-spotted stud(s) rotate through the spiral 
groove(which BTW is machined to have less stud/groove lash near the 
steering center and more lash at the extremes!). The usual response to all 
of this is to reduce the stud/groove lash by tightening the external 
adjuster. Now you have some spots that are too tight and some that are too 
loose. Yummy.

If all the suspension/steering parts are tight and right, you may find the 
'following' is at an acceptable level. My king pins are towards the outside 
of acceptable wear tolerance, but my tie rod ends are in great shape and 
I'm running NAPA HD gas truck shocks. As you may have guessed from the 
above, I haven't rebuilt the steering box yet tho' it needs it. I do 
currently have a set of bias ply tires on the truck that I'm trying to wear 
out(doesn't seem to be working) 'cause of my Scotch blood ;). They're 
acceptable, but just barely. The worse the freeway gets on one section of 
my commute the more wandering I do. Not dangerous at this point, but it 
keeps you awake. I have had radials(235-75/15LT's) on the truck before, and 
it does make a significant difference. Note that until I got rid of the old 
front shocks the radials didn't seem like much of an improvement. If you 
get radials(try for used if money's tight, there's always somebody who 
thinks the 235-75/15's look too wimpy on their new Yup-vee), make darn sure 
you get a true LT tire, not the 'P-metric' jobs. You want something 
equivalent to the old 6-ply load rating so you get the nice, stiff 
sidewalls that will keep your rig from wallowing around and plowing through 
corners(HUGE understeer with wimpy sidewalls). The max inflation pressure 
is a dead give-away. If the max is only 35psi-ish, it's not a 6PR 
equivalent.

I brought home an S p/u a few weeks ago that has a decent set of radials on 
it. I've been eyeing them pretty hard but haven't found the time to paint 
the wheels and put 'em on the B.

Jim