Tire cupping

[Crusty old shellback]

Typical of a shop like that, throw parts at it that wont fix the issue.

Do you have any other suggestions?
I can't see anything that stands out as the issue.
The track bar has slop in the bushings. And shocks have 62K miles on them.
I can not see or feel and play in the ball joints or tie rod ends. And wheel bearings seem good.

 

[G Mcpherson]

If those are worn then start with that. Process of elimination for wear items. Certainly won't hurt. If your alignment is in your spec.

 

[H3LZSN1P3R]

Do you have any other suggestions?
I can't see anything that stands out as the issue.
The track bar has slop in the bushings. And shocks have 62K miles on them.
I can not see or feel and play in the ball joints or tie rod ends. And wheel bearings seem good.

sure the trac bar could be replaced it wont fix the issue but if there is slop its worth changing. The shocks if they are not causing a bouncy ride then i would not bother changing them, the 4600 shocks last a long time not like a tradition oil shock. Shocks wont cause cupping on the edge they will cause odd wear across the whole tire in a very odd pattern.

When you check your ball joints do you have the axle supported and use a bar under the wheel to check the lower joint for play?

 

[Crusty old shellback]

sure the trac bar could be replaced it wont fix the issue but if there is slop its worth changing. The shocks if they are not causing a bouncy ride then i would not bother changing them, the 4600 shocks last a long time not like a tradition oil shock. Shocks wont cause cupping on the edge they will cause odd wear across the whole tire in a very odd pattern.

When you check your ball joints do you have the axle supported and use a bar under the wheel to check the lower joint for play?

Put the axle up on a jack stand. Checked up and down rotated the tire. With all 4 on the ground, had the wife swing the steering wheel 10 to 2. That's when I saw the play in the track bar.
Also lately, when I hit the little divits on the centerline stripe of the road, I get the death wobble for a bit. Never had that before

 

[Crusty old shellback]

Here's a few pictures. The cupping/scalloping is on the inside and outside of the tire.

 

[Crusty old shellback]

Just checked it again, both with tire on and tire off, no play in anything that I can see. Actually lifted the truck a little when prying up on my bar to check for slop in the bearing and ball joints.
My pry bar is a 4 foot 1 inch dia solid steel pole they used for aligning railroad track back in the day.

 

[G Mcpherson]

You could also pull a front shock and check it.

 

[H3LZSN1P3R]

Here's a few pictures. The cupping/scalloping is on the inside and outside of the tire. View attachment 72645View attachment 72646View attachment 72647View attachment 72648

What tire pressure are you running?

 

[Crusty old shellback]

I run 32F/28R cold.
That gives me 37F/33R hot when tires are up to temp.
But it's still a bit overinflated, especially in the rear as I only get wear on the center 2/3 of the tire.

I've played with pressures from 42F/37R hot down to where I am now. Any more and I can see daylight between the outer treads and the pavement.

 

[dslbrnr]

Front tire pressure seems low. I'd go at least 45-50 PSI up front where most of the weight is JMO

 

[AH64ID]

Front tire pressure seems low. I'd go at least 45-50 PSI up front where most of the weight is JMO

Nah, not for a PW with 35x12.50R17. 30 psi will support 4,310lbs. 32 psi is likely right at 4,500lbs.

The FAWR is only 4,750 so 35 psi is the most ever needed with those tires.

 

[Crusty old shellback]

My truck weighs:
4280 front axle
3080 rear axle.
I had it weighed.
This was when I had BFG 35x12.50R17 tires on it.

 

[Crusty old shellback]

So everything I see in my research says:
alingment; had it done after the issue started.
Balance; added balance beads last week.
Shocks. Looking at buying a set.

Anyone got any other ideas before I go drop $1500 on shocks and track bar.

 

[Poolmonkey]

My truck sees a lot of dirt and gravel and I mean a lot..at speed, we travel long distance off road regularly.
Everything checks good by all who have looked including me and it’s been thuren-ed twice, is on it’s third set of shocks..tires rotated religiously.
I have accepted that using this truck like that is going to eat tires.
My solid axle Scout II that I hunted with for years did the same, I was spoiled by the 90 Bronco and then the Raptor both of which didn’t abuse tires.
Well, the Raptor could eat a set in 1000 miles and did to it’s factory BFGs. It destroyed them by removing big chunks of tread doing 90 + off road and me being silly.
Anyway..It is what it is with this PW thing, apparently.
No death wobble here, just a beaten and wobbly third set of treads in 24k.
I would replace that track bar. Have you been on more dirt/gravel than before?

 

[G Mcpherson]

Get them through Thuren for less than a Carli Track Bar and Fox Shocks. A little anyway.

 

[Crusty old shellback]

My truck sees a lot of dirt and gravel and I mean a lot..at speed, we travel long distance off road regularly.
Everything checks good by all who have looked including me and it’s been thuren-ed twice, is on it’s third set of shocks..tires rotated religiously.
I have accepted that using this truck like that is going to eat tires.
My solid axle Scout II that I hunted with for years did the same, I was spoiled by the 90 Bronco and then the Raptor both of which didn’t abuse tires.
Well, the Raptor could eat a set in 1000 miles and did to it’s factory BFGs. It destroyed them by removing big chunks of tread doing 90 + off road and me being silly.
Anyway..It is what it is with this PW thing, apparently.
No death wobble here, just a beaten and wobbly third set of treads in 24k.
I would replace that track bar. Have you been on more dirt/gravel than before?

It's seen it's share of off road. Baja, and now here in Reno.
And now I live 2 miles down a dirt road that is not always smooth, they do grade it when it gets rough.
Had no problems with the BFGs in Baja.

 

[LateToTheParty]

So everything I see in my research says:
alingment; had it done after the issue started.
Balance; added balance beads last week.
Shocks. Looking at buying a set.

Anyone got any other ideas before I go drop $1500 on shocks and track bar.

Any reason you don't want to pull the front shocks and check them before simply buying new?

 

[Crusty old shellback]

I can pull them, but at 61K miles, I'm sure they are wore out.

 

[Rockcrawlindude]

Not uncommon to wear front tire edges on a truck with 4K lb on the front axle. The tires are going to roll and scrub every time you turn. Doesn’t necessarily mean there is something wrong with the truck.

I don’t see cupping in your pictures. Cupping usually shows a distinct high to low spot over a lug, most noticeable at sipes where a low meets a high. Looks to me like you’re just wearing edges.

Tire cupping pics from internet

 

[Crusty old shellback]

It's hard to see but there is cupping on both edges, just hard to see, plus I'm rotating about every 2K miles to try and minimize it. None of the other tires I had on for 30K plus miles did this.