suspension issues... do I need new shocks?

[Gulfport4Runner]

I have a '97 4Runner SR5 w/ 98k miles. I think the suspension needs some work. When I go over small dips or bumps, the rear hits w/ a thud and has very poor recovery. I'm trying to determine if the problem is w/ the shocks, suspension bar, springs or something else.

Any feedback is appreciated.

 

[Chicago-Spike]

While my expertise is with motorcycles, this sounds to me like the shocks are done and the truck is hitting the "Bump stop". Meaning, the shocks are not absorbing the bumps and the truck bottoms out.

 

[Kmvreter]

You can check it out yourself by doing the following.

Start with the shocks. Grab the corner of a bumper. Start pushing down and pulling up to cycle the suspension. Do this cycle several times to build up a "wave" pattern. Let go of the bumper after a final push down. The shocks should recover and stop any movement within 1 to 1 1/2 cycles (one up, one more down and maybe up again.) Now do this on all 4 corners of the vehicle. You will easily recognize a difference between the rebound of 1 or 2 shocks if a problem exists. Try this on a similar sized newer vehicle if you aren't sure how it should feel. Yours will obviously be different than new but it will give a good indication.

If this doesn't show a problem then the only other thing I would do is crawl under and inspect the springs. Look closely toward each end of a spring to see if it's collapsed which means it's cracked. Visually compare one side to the other if you aren't sure.
While you're under there grab onto various bars and links to check for movement. Everything should be firm. Again, compare one side to another if you aren't sure.

Hope this helps.