This is a 6cyl AWD vehicle I purchased new. Despite proper inflation, frequent rotation, an alignment and tire replacement, I cannot prevent the tires from cupping, which leads to terrible road noise. The vehicle came with Kumho Crugens and I am running Michelin Premier LTX’s on it now. The tires were silent on the road when I first bought it. The tire size is 235/65/17. Help!
You need shocks and/or struts. But once the problem has started it will continue until you replace the tires.
I don"t think shocks and struts are the problem on a 4 year old SUV. Now some cars tend to do this even if they are in perfect alignment with the shocks and struts in good shape. Some do this more with one brand of tire than another.
I think it is an alignment and an owner problem. I think the alignment is not right for the way you drive.
If you’ve been having the alignment checked when you get new tires because of the cupping issue and it is in spec or they make small adjustments and you still have the problem… you need to have a chat with a shop that specializes in alignment. Look for a local suspension specialist. The shop might be able to make this better.
If you know a good body shop or two - ask them where they send crashed vehicles to be aligned. That place probably does more inspection, and a more professional alignment job, than you have been getting.
Everything has been attempted to prevent the tire cupping.
The only thing that hasn’t been tried is replace the struts.
Are there many bumps on the roads you travel? I’m thinking about pot holes, speed humps, and anything else like that. If so, how fast do you drive over them? If it’s too fast and you do it often enough, that can shorten the life of your struts. I don’t know you and don’t know how you drive. It’s one possibility.
I looked up alignment specs on this car. Front toe in can be 0.10 to 0.27 degrees toe in. Rear is 0.24 toe out to 0.42 degrees toe in. 0.42 degrees toe in is way too much and will cup the tire. Since the spec allows 0.10 toe in, setting it there will help. Fron toe should be the same or a little more, say 0.15 toe in.
I think that will fix your problem if you can find an alignment shop to set it that way for you.
Cupping or feather edging? Sometimes those terms are used interchangeably but they and their causes are different.
First, most published alignment specs are too wide - by half. It is common for alignment techs to just get the vehicle “In Spec” - and that isn’t good enough for good tire wear. The alignment has to be within the inner half of the spec. In the case of toe, that means within 0.06° of the target value (I am not arguing about the target value, just the tolerance!)
Second, any camber over 1° is too much. If the spec allows for more than 1° camber, then the spec is not going to get you good tire wear. Yes, the vehicle won’t handle as well, but that is the choice!
Third, it is common for alignment techs to think that if the factory doesn’t allow for adjustment, it can’t or shouldn’t be adjusted. This is very wrong. It may take a camber plate or an eccentric bolt (extra cost!) to get it right and many alignment techs don’t want to argue with customers about that extra cost.
So the first thing to do is get an alignment with a tech who will give you the prints outs. He needs to be willing to dial the parameters to the inner half of the spec even if it means getting a part to will allow that to be done. You have to be willing to pay the cost of those parts. He also needs to be willing to dial the camber out if it is over 1°. (That may take some discussion!)
Speaking for myself and other alignment techs I know, we have never been of the type that close is good enough nor have we ignored a problem such as camber being out of spec with camber being built in. Customers have always been alerted to any potential issues.
Granted, there are some who fit the close enough mold. In some cases getting close is the only option as any wear at all in wheel bearings, steering or suspension components will mean that the alignment will never be dead-on until the problem is fixed.
At this point I’m not sure if we are talking about cupping or feather edging as some people use those terms to mean the same thing. Maybe terminology varies by locale but to me cupping means balance or struts/shocks and feather edging means an alignment issue.
That is my understanding also.
Perhaps the OP can clarify matters for us.