2001 Yukon XL SLT 2WD Porpoising Like a Boat

Hello,
Looking to see if I can get some help. 2001 Yukon XL SLT 2WD is porpoising when I go over dips in the road, thing is like a boat on the water at higher speeds. The thing is it's only happening on the passenger side, the fist thing I replaced was the shocks but that didn't help. I have also replaced the steering box, inner and outer tie rod ends as well as all of the sway bar bushings. The torsion bar seems to be ok since it's not sagging also the upper and lower control arms seem to be in good shape. The Yukon has just over 200,000 miles on it and is now primarily used for baseball practice and such. Any help would be greatly appreciated.

James

New set of rear springs but also, what brand and quality of shock? Tire sizes and air pressure too? Rear sway bar bushings?

What about the front bump stop thingies? I keep reading on here how important they are to the suspension on this gen.

89Suburban said:

What about the front bump stop thingies? I keep reading on here how important they are to the suspension on this gen.

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Good call. Forgot completely about them.

89Suburban said:

What about the front bump stop thingies? I keep reading on here how important they are to the suspension on this gen.

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Definitely check out the jounce stops.

And check your allignement. Especially the caster and toe.

If the caster on right an left side is severe different, your toe will change in different amounts, according to steering ankle, what will result in unstable driving.

OR VietVet said:

New set of rear springs but also, what brand and quality of shock? Tire sizes and air pressure too? Rear sway bar bushings?

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Original GM shocks and OEM tire size. Have not touched the back yet.

Sam Harris said:

Definitely check out the jounce stops. View attachment 396339

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Will be replacing the jounce stops.

jamie2 said:

Original GM shocks and OEM tire size. Have not touched the back yet.

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Are you saying you only did the front shocks?

nonickatall said:

And check your allignement. Especially the caster and toe.

If the caster on right an left side is severe different, your toe will change in different amounts, according to steering ankle, what will result in unstable driving.

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Any update on this? Did you try adjusting the caster? I am having this EXACT issue and can't figure it out. See my thread.