Every time I include a pair of jeans in a wash load, the machine can’t make it through the spin cycle without getting stuck several times because of an unbalanced load. Usually I just give up and pull the jeans out and throw it in the dryer.
I just empty the pockets, turn the jeans inside-out, ball them up and put them in with the rest of the “darks,” but always making sure the machine isn’t overloaded. I’m used to machines with the door up front, rather than vertical loaders; when I used a vertical I had to relearn how to size loads, as I’d tend to overload.
For a door-in-front machine, the load shouldn’t go above 2/3 of the height of the space. About half for a vertical. IME, Your Machine Will Likely Vary, etc etc.
And that’s why I always wash two pairs of jeans instead of one. Put them in first, arranged around the center washer (assuming you have a top-loading machine).
As Beadalin says, arrange them in a circle around the perimeter of the washer as you load it – put the waist at 12:00 then loosely wrap the legs around the basket, so the ankles of the pants (what do you call the cuffs when there are no cuffs?) meet up again with the waist the long way around – or at least get to 9:00. Do the same thing with towels and other heavy stuff.
I second An Arky’s point about maybe having a problem with your washer. My washer used to have one of its legs misadjusted by like 1/32 of an inch. It worked fine for most loads, but the weight of towels made is vibrate something awful. I readjusted the legs and haven’t had a problem since.
I just shove things in pretty much any-old-how, except bedding. Very rarely unbalanced.
The only exception that I can bring to mind is a waterproof jacket.
Front loader. The same has applied for the past four machines (30 years).
I think it’s your washer. I do probably 2 loads of laundry a week (not counting whites) and make no effort to evenly distribute jeans or balance the loads. This is in a machine I bought new about 4 years ago, but was one of the cheapest I could find. I’ve never had a problem. I’m not sure if it’s possible, but maybe there’s something you can adjust to make it less sensitive. Or make sure it’s level.
I’ve never had problems with jeans. If I put too many towels in and they are grouped together in the spin cycle I would have a problem. Maybe you’re overloading the machine?
One reason to turn them inside-out is so that the agitation spares them any excessive wear-and-tear on the fabric fibers, and thus keeps them from looking faded and washed-out quite so fast. And you ball them up because with the seams on the outside, there are more chances for the jeans to get tangled and snagged under the agitator vanes.
Jeans are supposed to look faded. Hell, a lot of people pay extra for jeans that come pre-faded. If you ball them up, they’re just going to get unballed in the machine anyway - unless you tie them in a knot or something, and then they’re not getting fully washed.
As for the OP, your washing machine sucks. Get it fixed or get a new one.