Help Me Trouble Shoot: Cupped Tires and Front End Rattle

[Rustler]

I am trying to trouble shoot cupped front tires and a front end rattle, and would welcome any feedback or experience you all have. Here is some relevant info:

Truck: 2018 Raptor, 23k miles, bought new, no modifications, original tires rotated three times over course of 23k miles, sees mostly pavement, some gravel roads and some genuine 4WD/Offroad.

Symptoms: Cupping on inside of front tires (at least I think it's cupping, they are wearing more on the inside of the tread than outside, and it seems like every other tread block on the inside is worn more. It's hard to capture in pics but I'll try in a follow up post). There is a metallic rattle which is getting progressively worse, sounds like it's coming from the front end.

What's been done so far: Dealer has acknowledge the cupping and front end rattle, and they had it in for a day this week but they are saying they are still "unsure" what the issue is. They tell me they are taking it up with Ford and it will take a few days to hear back.

On the dealers inspection the alignment was spot on, no adjustment needed. The tires were slightly out of balance, but they did not think enough to cause the tire wear. I never felt any imbalance. The mechanic put chassis ears on it and thinks he has isolated the noise to the front shock assembly. There is nothing loose underneath (I don't know whether they tested both under load and unsprung), there is no seeping from the shocks. The shocks seem to be performing fine on road and off, no porpoising or excessive bounce. Also, no noise from the suspension when it's compressed smoothly over road undulations. Everything feels solid, but it doesn't sound it. The rattle only happens when you hit a seam or harsh bump. Offroad or on washboard gravel it sounds like I'm storing bolts in the skid plate.

Anyway, I'm waiting for the dealer to get back to me but I'm... skeptical, shall we say, of the dealer.

I would love to have my own theory to test moving foward.

What say you Raptor experts?

 

[Donmatteo]

What PSI are you running?

 

[CoronaRaptor]

How have they been doing the tire rotation?? Ask them before telling them the correct way. SOme dealers like to do front to back, back to front, if that's the case, tell them to buy you new tires.

 

[Rustler]

I typically run mnfgr recommended inflation (38 here, if I recall). I add a few pounds in the rear when towing my micro-camper (about 1,500 lbs).

@CoronaRaptor, they were absolutely mis-rotated (front to back, not cross rotated, see below for long and boring story) do you think that's sufficient to cause the cupping, or would that just cause excessive (but even) inside wear? What about the front end noise? I have read that a blown shock is a classic cause of cupping, but don't know that from my own experience.

The mis-rotation is a whole part of the story I left out so as not to bore you all, but it's probably a relevant little nugget:

On my last oil change/rotation, I asked them to look at the cupping and give me an opinion on what was causing it. When I picked up the truck, the tech's written report said: "Uneven tire wear, replacement recommended." To which I said, "no $h!t, that's what I told you when I dropped it off, what I'm interested in is what caused it." I was fed some BS at that point that "Raptor's just do that to their tires." So I went out to my truck and gave it a good look over, and sure enough, they rotated front to back. I returned with the manual to ask why they weren't following Ford's recommendation and at that point the service person clammed up I next heard from the head of the service department.

Well, she has been very forthcoming. Admitted that the tires should have been cross rotated, and scheduled a quick follow-up to check alignment and the front end noise to be sure we know what is causing it (what I described above).

At this juncture it is her position that the incorrect rotations (they did all three that way apparently) did not cause the cupping. But that there is some issue that is causing the noise in the front, and that may be related to the cupping.

I tend to think that the mis-rotation is not the cause of the cupping, but that it greatly exacerbated/accelerated the issue. What do you all think? However, I have reserved my rights on that issue while we check off likely causes. For instance, I would have felt like a **** if I'd insisted that the mis-rotation caused the cupping, only to then find out that the alignment was way out of whack and the likely cause. If the mis-rotation continues to look like the only known issue, then yeah, I'm going to fight like hell for a new set of tires. However, if there is another likely cause, I will look for something less than a full set as compensation for making the uneven wear worse. Maybe ask for my next set at cost with a free mount, or something to that effect.

Needless to say I am skeptical of this dealership, but it's the only one within 90 miles, and as long as the head of service continues to take this seriously and work honestly towards a solution I'll give her a chance.

What I am hoping for here is to be able to follow-up with the head of service armed with some better idea, and maybe relevant experience from you all, about what is going on.

 

[CoronaRaptor]

I typically run mnfgr recommended inflation (38 here, if I recall). I add a few pounds in the rear when towing my micro-camper (about 1,500 lbs).

@CoronaRaptor, they were absolutely mis-rotated (front to back, not cross rotated, see below for long and boring story) do you think that's sufficient to cause the cupping, or would that just cause excessive (but even) inside wear? What about the front end noise? I have read that a blown shock is a classic cause of cupping, but don't know that from my own experience.

The mis-rotation is a whole part of the story I left out so as not to bore you all, but it's probably a relevant little nugget:

On my last oil change/rotation, I asked them to look at the cupping and give me an opinion on what was causing it. When I picked up the truck, the tech's written report said: "Uneven tire wear, replacement recommended." To which I said, "no $h!t, that's what I told you when I dropped it off, what I'm interested in is what caused it." I was fed some BS at that point that "Raptor's just do that to their tires." So I went out to my truck and gave it a good look over, and sure enough, they rotated front to back. I returned with the manual to ask why they weren't following Ford's recommendation and at that point the service person clammed up I next heard from the head of the service department.

Well, she has been very forthcoming. Admitted that the tires should have been cross rotated, and scheduled a quick follow-up to check alignment and the front end noise to be sure we know what is causing it (what I described above).

At this juncture it is her position that the incorrect rotations (they did all three that way apparently) did not cause the cupping. But that there is some issue that is causing the noise in the front, and that may be related to the cupping.

I tend to think that the mis-rotation is not the cause of the cupping, but that it greatly exacerbated/accelerated the issue. What do you all think? However, I have reserved my rights on that issue while we check off likely causes. For instance, I would have felt like a **** if I'd insisted that the mis-rotation caused the cupping, only to then find out that the alignment was way out of whack and the likely cause. If the mis-rotation continues to look like the only known issue, then yeah, I'm going to fight like hell for a new set of tires. However, if there is another likely cause, I will look for something less than a full set as compensation for making the uneven wear worse. Maybe ask for my next set at cost with a free mount, or something to that effect.

Needless to say I am skeptical of this dealership, but it's the only one within 90 miles, and as long as the head of service continues to take this seriously and work honestly towards a solution I'll give her a chance.

What I am hoping for here is to be able to follow-up with the head of service armed with some better idea, and maybe relevant experience from you all, about what is going on.

This is why I mentioned the tire rotation because my original dealer was doing the same thing when my truck was new, exact same scenario, I stopped going there and started doing my own oil changes and tire rotations from there on. You will get cupping from 4x4s if you don't rotate your tires properly, its been like that since the beginning of time, well, my time anyway, lol. Get yourself a cordless impact, it's barely an extra 15 mins to add onto your oil change.

 

[atombombmx]

Time for new shock or rebuild existing,

 

[Winchester30]

I have similar rattle issues in front end, tires wearing fine though 34/32.
Also a 2018 with 24k.
Have not had dealer inspect yet.

 

[jabroni619]

My factory KO2's started cupping very prematurely, like around 15-20k miles. Ended up replacing them around 32k miles even though I had plenty of tread left just because the road noise became too much.

 

[NASSTY]

My factory KO2's started cupping very prematurely, like around 15-20k miles. Ended up replacing them around 32k miles even though I had plenty of tread left just because the road noise became too much.

I had the stock KO2's swapped over to aftermarket wheels @ 4000 miles on my 2017. The guy at the tire shop said my tires were cupping pretty bad for only 4000 miles. I sold those tires when they had 18K miles on them and they were about half tread.

 

[Mister Pinky]

I wonder how aggressive the camber is set on the Raptor stock alignment vs. the regular F150s.

Camber will prematurely wear the inside edges of your tires every time. This combined with improper rotation methods may have worn out your tires.