Posted By: fred c Ployester vs radial tires? - Fri Apr 09 2021 01:50 PM
I have a 46 Chevy 1/2 ton that has been professional restored. It has an annoying tendency to wander while I'm driving. I know this can be caused by many problems but I have had 2 people tell me that replacing the current 6.70-15 4 ply polyester tires with modern radial tires would make a huge difference in handling. I was told radial tires with modern roads are much better than the old style tires. Has anyone replaced polyester tires with radials and experienced a big improvement in handling?
Posted By: Justhorsenround Re: Ployester vs radial tires? - Fri Apr 09 2021 02:02 PM
Back in the 70s when I sold tires our training told us that radials did not follow the imperfections in the road whereas poly and other bias ply tires followed everything causing a lot of unnecessary steering input.
Posted By: Phak1 Re: Ployester vs radial tires? - Fri Apr 09 2021 02:19 PM
My truck wandered so badly it was like “trying to herd cattle down the road” (a phrase I stole from HRL) and my truck came with radials. It wasn’t until I fixed a worn spring mount, rebuilt the springs, replaced the king pins, tie rod ends and adjusted the steering box that I got her tamed down. I’m not saying you’ll have to replace everything that I did, but any one of those items can cause your truck to wander.

Now bias ply tires as you probably know will pull you from side to side when crossing inline cracks, but they shouldn’t cause you to wander.

Jack up the front of your truck and move things around (wheels, tie rods, steering box, etc.), and see if anything has any play. Also wheel alignment plays into it. Read about adjusting your steering box. It’s a fairly easy procedure and can cause the wandering your talking about.

Here is a link on adjusting your steering box.
Posted By: fred c Re: Ployester vs radial tires? - Fri Apr 09 2021 03:05 PM
thank you both for the input.
Posted By: Lightholder's Dad Re: Ployester vs radial tires? - Fri Apr 09 2021 03:24 PM
I converted my '37 half ton, '51 half ton and '50 2 ton COE from bias tires to radials. In all cases I drove the trucks before and after the conversion without other interventions (like adjusting steering or replacing suspension parts) and the improvement in handling was dramatic. I also bought new bias tires for my '42 half ton, which I have owned for over 20 years, and that also improved handling dramatically. Clearly, new thicker tread helps in handling in both types of tires but you won't be disappointed with the radials.
Posted By: WE b OLD Re: Ployester vs radial tires? - Fri Apr 09 2021 04:18 PM
I have radials on 1954 1/2 ton and put them almost from the beginning back in 1983, I would not have anything else. The bias tires would jump lanes. I had polyglas added on my 1969 Plymouth Sport Fury for the same reason. The polys were the forerunner of radials. I even paid extra when I bought the Plymouth new.
Posted By: Barnfind49 Re: Ployester vs radial tires? - Fri Apr 09 2021 06:01 PM
Tires are probably last on the list of what it is. I have seen pros not do alignments or leave stuff loose. 1/2” of toe out will make a truck drive like the worst junk you could imagine..... then a few turns to 1/8” toe in and it will cruise with 1 hand on the wheel and float down the road with almost no steering input. Are radials better? Yes....... but they might not fix your problem even though some one automatically told you thats your problem.
Posted By: Wally / Montana Re: Ployester vs radial tires? - Fri Apr 09 2021 06:37 PM
After I switched from bias to radials, I could bring a cup of coffee with me to work without the coffee sloshing out.
Posted By: fred c Re: Ployester vs radial tires? - Fri Apr 09 2021 06:41 PM
thanks everyone for the info. I think I'll start with checking out the steering components. Then try to find someone that can align the front end. If that works I'll save money on the tires. If it doesn't work, I'll spend the money for the radial tires.
Posted By: 55shaker Re: Ployester vs radial tires? - Fri Apr 09 2021 11:11 PM
Sounds like a good plan Fred.
Posted By: John Milliman Re: Ployester vs radial tires? - Fri Apr 09 2021 11:36 PM
Yet another opinion ... smile

Fred, I am running (new) bias ply tires on my truck. I have made a few upgrades (rear axle gearing, engine upgrade to a 261) that now allow me to cruise comfortably at 60-65 with dashes to 70 comfortable, as well. Thanks to Sweet and others, my steering has been adjusted to specs (adjustment to alignment as well as the steering box). I find that the truck steers just fine.

I have *not* replaced my tie rod ends. My truck has less the 65k miles on it, and steers just fine with everything else adjusted properly so I'm kicking *that* can down the road a little further ... smile.

Radials obviously and without debate give you a better ride and steering. But, with all other things being equal (i.e., a few adjustments and tweaks), bias plys can do an adequate job. Depends on your driving habits and how much you plan to drive the truck.

Don't get me wrong here -- If I could keep my stock appearing wheels (and hubcaps) without spending ginormous amounts of cash on wheel mods, I would be running radials today. But I can't afford the mods to make the 17-inch wheels work for my truck, so I am stuck with the bias plys. And I find they work pretty good. Not as great as radials, but not too bad. They remind me to keep it under 70. smile

I would think/hope you would want to make sure your steering/alignment is all up to spec anyway wink. And while we're at it, don't forget to throw some love at your brakes. Have you installed some seatbelts yet? If we're talking driving on modern roads here at modern speeds (or there abouts ...), let's be sure we're safe smile
Posted By: Joe H Re: Ployester vs radial tires? - Sat Apr 10 2021 02:07 PM
Take a quick look at the front springs where they mount to the axle, does it have CASTER wedges and are they pointing the right direction? The wedge should have the thicker end towards the rear of the truck. With out the proper caster, your truck will be all over the road. How does the steering wheel return after making a turn?
Posted By: rickmg Re: Ployester vs radial tires? - Sat Apr 10 2021 06:07 PM
I had bias ply tires on my 39 3/4 ton stake truck for 30+ years, replaced twice with new bias ply. Two years ago I switched to radial. I knew the difference in handling just backing out of the barn. Steering wheel turns a lot easier at a stand still too. The radials have a bias ply look to them.

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