Uneven wear on tyres

[Derren]

Good morning...

My Hilux's tyres (BFG MT) are wearing uneveningly (see photo) - every second "block" is worn more. This is from the front right, front left is similar.

Tyre fitment place reckons shocks. The shocks have done approximately 50,000 km so they could be due for replacement although 99.9% of that has been on tar.
The issue with the tyres started probably 10,000 to 15,000 km ago (maybe longer). So in theory, if it is the shocks (TJM XGS Gold), they were a waste of money.

What are your thoughts? Is it possible that the camber/toe-in is out but I have had alignment, etc done so would think that would all be sorted. According to the alignment report they were within spec to begin with (now a little bit better in spec after adjustment).

WornTyre.jpg

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[BenRich]

Would love to hear the answer. Cannot believe that you will only get 50000km's out of those shocks!

[Toppie4x4]

yip agree 50,000km is not a lot for s set of shocks??

[Derren]

If I had driven gravel all the time then maybe but at least 49,000 km of that 50,000 km was on tar

[Mars]

I have been wondering why I haven't seen such a discussion and have actually been meaning to start one based on my own experience using all terrain tyres now for 155 000 ks.

I have noticed the same thing on two sets of A/T tyres now as well as on one set of a colleague with whom I have been discussing the phenomenon.

Actually there are two kinds of uneven wear I have noticed but I'm not sure if the two are related although I suspect so.

The first that became apparent with a set of BF Goodrich K01 A/Ts and a set of Bridgestone D694 A/Ts both on my Lux was the advanced wear of every alternate block on the tyre. My colleague also has D694s with almost the same kilos as mine. As the BFs grew older I would accept that it could be due to shocks but on the Bridgestones definitely not as I replaced the shocks very shortly after getting the Bridgestones as I did not want uneven wear. The same thing happened to the Bridgestones also after about 50 000 ks. Perhaps the Bridgestones took a little longer but I cannot recall exactly. 95% of kilometres were also covered on tar and mostly town driving.

So the story about the shocks is absolute BS. (and no that does not stand for Bridgestone....)

The other phenomenon I noticed on both sets of tyres is that the leading edges of the blocks seemed to wear less than the trailing edges. The trailing edges having a smooth rounded appearance but the leading edges having a sharp edge and eventually over time almost a forming a "fringe" for the want of a better word. This is accompanied by a marked increase in tyre noise. To the point where I am wondering if the entire drive train's bearings are going. I suspect it is more a case of the leading edges wearing less than the trailing edges wearing more as the blocks appear flat on top and not tapered in the direction of the trailing edges.

When I fitted the Bridgestones I was advised to keep the pressure at 2.5 Bar. This I have religiously done using nitrogen. I have also rotated the tyres at every 10 000 ks, had them balanced and checked wheel alignment every single time.

I recently had a discussion with a guy at a fitment centre about this and he advised that the tyres should be rotated every 7500 ks as the tread pattern has bigger blocks. He also advised that the tyres should be rotated cross-wise in the following manner. Front Right to left rear, front left to right rear and the rear tyres in their positions to the front i.e. Left stays left and right stays right. This sequence is followed at every rotation. Now I know that conventional wisdom states that one should not cross rotate radials but I wondered about the uneven wear which is clearly directional and if cross rotation would not address that even before getting this advice.

Seeing as I had already rotated my tyres shortly before getting this advice and that I was getting very sick and tired of the noise I decided to swap the tyres from right to left and vice versa. I did this before driving down to Cape Town two weeks ago. I expected the tyres to be noisier but interestingly they weren't. After covering almost 4000 ks over the past two weeks the noise has gradually declined. It is also clear that there is some more wear taking place on the trailing edges of the blocks now (which used to be the leading edges).

It will be interesting to note if the wear on the tyres speeds up now but I was not prepared to live with the noise anymore.

If this will address the wear on every second block as mentioned by the OP remains to be seen as I cannot see that that could also be ascribed to the direction of rotation of the tyres.

I really hope someone with knowledge on this subject would chime in here.

[CasKru]

I'm speaking under correction but all mud terrains do this. That is why you have to rotate them more often or run them at a higher pressure.

[Derren]

Hi Mars,

Great (in a way), I am not the only one.
Yes, what you have described is what I have experienced including the one edge wearing more than the other.


From new I had whatever HT tyres the bakkie came with and they wore ok.
I then fitted BFG AT and they also wore well.
Then a set of Coopers STT and when I replaced them with the BFG MT they also had this "peculiar" wear.

Now after the BFG MT, I have Coopers ST/MAXX and would like them to wear better. Driving the bakkie today on my new tyres as a like driving a new bakkie... smooth... quiet... and no vibration, etc...

I probably will look into the shocks and have them removed to check them out properly before deciding to replace.

And rotation more often than I used to is on the cards.

Thanks CasKru.

[CasKru]

PS: some other guys description of what happens

That is called lack of rotation... Mud tires develop this much more easily than other styles of tread, because of the blocks, where as other treads overlap more in pattern from side to side and front to back the load of the vehicle is spread more evenly across the footprint. Ever seen wore down tractor tires? The leading edges of the lugs almost always wear down more quickly than the rest of the lugs. Normal AT tires can survive a long time on lack of rotation, but do it with mud tires and you've just 1/2ed the life of your tires. Get them re-balanced and rotated they will straighten out, but by the time they do, the fronts will be cupping again.

[Derren]

[Mars]

Except for one thing that I am absolutely sure of and that is that the leading edges wear less. I rotated every 10 000 as advised which now seems is too long. I am also talking about A/Ts and not MTs. My Buddy at work is just as fastidious about his bakkie as I am about mine (if not more).

Thanks Cassie