Assessing tire condition- NDT bias tires

[Ajax MD]

I tried searching this but came up empty.

I'm not an expert on bias tires with tubes and I'm still learning about their peculiarities. Visually, how much checking (cracking) is acceptable before you decide that a tire is unsafe?

Bear in mind that I don't haul commercially and my truck is normally unloaded. I haul a few tons of pellets once a year. My tires all have plenty of tread but they're all of various ages.

 

[NDT]

The 8 on the rear can be ho hum but your steer tires need to be exceptional. The military tires are special OZ rubber that can last decades, as opposed to the commercial tires uncle started using recently. Well not exactly recently, 20 years ago.

 

[Ajax MD]

The 8 on the rear can be ho hum but your steer tires need to be exceptional. The military tires are special OZ rubber that can last decades, as opposed to the commercial tires uncle started using recently. Well not exactly recently, 20 years ago.

Thanks for that. My steering tires are the best in the group.

 

[juanprado]

I had 2 deeply cracked tires on a trailer from the 60's with half worn tread and I suspect the tires were original. I was concerned as I had a 80 mile recovery.
Tires stayed stone cold and did not give any trouble like they are literally designed to last a lifetime......... I also think they have like 12 plys or more unlike modern stuff.

But I have had issues with older tires in that the tubes deteriorate. I had one tube come out like shredded cheese. It was not a blowout but just literally fell apart. I have also had a bad flap. I think the tubes and flaps are more likely to fail than a NDT tire......

 

[Ajax MD]

@juanprado I did have a good tire that the tube let go on. I plan on putting a new tube in it and keeping it as a spare. The part where the valve stem attaches failed.

Your point about temperature is well taken. I always walk around and touch all the tires and hubs after a drive, just to see what's happening.

 

[juanprado]

I had the same problem area but the flap had torn and shifted where the valve went through and caused the problem. I had not really even considered flaps as trouble items before this.

 

[US6x4]

The military tires are special OZ rubber that can last decades,

What is OZ rubber? I haven't heard of this term but I've had my suspicions that military rubber was exempt from the EPA on their quest to eradicate all of the good stuff that actually works.

 

[BKubu]

I don't know what it stands for, but I do recall seeing OZ marked on the sidewall of some of my tires. I could have been on all of them. I never checked. I know I have seen it before, though.

 

[williamh]

Dry rot is a crap shoot. I have had tires with cracks that I drove on for years , made in the 60’s recapped in the 70’s driven till 2020. Still worked till I put on some “newer” shoes. Have some “army” recaps from the 90’s that looked new but came apart as soon as they hit blacktop.

 

[US6x4]

I found this little snippet explaining the OZ in a little more detail.

 

[G744]

At least no one said "They were made in Australia"...

DG

 

[Ajax MD]

Ah, interesting. I've seen the OZ on several of the tires. I had no idea what it meant.
I have a few manufacturers on hand. I notice that the Titan T-Hawk tires do not have the OZ marking.