The term “Slipped Belt” implies that a tire’s belt was in one position and moved to another position. I hope I don’t have to explain why that simply isn’t possible.
The 2 most common usages for the term are:
1) For a tread separation – and while a misplaced belt COULD result in a tread separation, tread separations are very rarely caused by a misplaced belt – so one can’t use the term unless one has X-ray vision.
2) For the cause of irregular wear – and misplaced belts rarely cause irregular wear. Irregular wear is usually caused by mis-alignment. Again, X ray vision is required here.
Chaissos asked “……but what was it? I'd rather know what it was so I can be correct from here out…..”
Not enough information. If it was a tread separation, with a few rare exceptions, these take thousands of miles to develop.
Cigroller asked “….. so if a "slipped belt" - or internal issue with the tire's structure is impossible what does cause tire issues with unworn tires (such as new) or with tires that have no measurable wear issues?....”
As I explained above, the term applies to a specific condition. If we expand the term to include a mis-placed belt, then a pull could be caused by that – but the use of that term is rarely applied to that situation.
But, cig, not enough information. What was the issue that developed suddenly? A pull would be there from the git-go.
There are a lot of things that can happen, only some of which are caused by the internal structure of the tire – and typically, these don’t appear suddenly. Even tread separations develop over time – typically thousands of miles to start and they grow from a barely perceptible vibration to a pronounced one over hundreds of miles.
There are a lot of terms that are commonly used in the retail end tire business that don't quite fit - which is why the manufacturing and design end of the business never uses those terms. This one is particularly onerous as it applies to something that can not be seen without cutting the tire apart.