2007 cupping on rear tires

Will jumping up and down on a Tacoma bumper actually make the suspension move appreciably? Before I put on my new KYB shocks (recently, shortly after buying the truck), I tried this and there was very little movement. Shocks/struts were original, so 10 years and 111K miles. Factory rear leaf springs. But I only weigh around 150 lbs. so that may factor in the lack of movement.

I've found this test generally works fine on a passenger car tho.

 

Correct, you're not going to get much movement on a 4Runner and weighing only 150 lbs. (Must be nice!) That's why the bounce test is of limited value in my book.

 

So changed the shocks , hopefully this remedies the cupping . I put stock on it , $53 each at the stealership.

 

Remember, assuming the shocks were the problem, replacing them will prevent further cupping. It won't fix what's already there. I run into so many people that think tire wear gets reversed when the root cause is fixed.

 

The tire should wear itself flat again I’m guessing

 

Bad assumption. The tires will continue to bounce, although the new shock will try to dampen the motion.

In reality, the rear tires should be replaced.

 

That's exactly my point. They will not. Although they will somewhat correct the wear pattern, the majority of the cupping is there to stay.

 

Eh I see what you’re saying , I had cupping on my fronts before this started and when I would rotate the tires the rear would wear them flat again .

 

Cupping at the rear tires I would check the rear shocks, maybe they are worn out especially if they have lots of miles on them.

 

Yep that’s the consensus , I changed them this past weekend .