Peterbilt rough ride

Hi I have a 2004 379 with a 63in stand up with low air leaf suspension about 6 months ago it developed this terrible bounce or shutter while going over bumps it is only while hitting a bump like a lip of a bridge or pot hole will not do it on smooth road it is way worse bobtailing literally feels like the cab is gonna bounce of the frame put a trailer and load on it still does it but feels weighted down from the weight. I can also feel it when the trailer goes over the bumps to for example if I’m turning a corner and the truck axles miss the pot hole but the trailer tire hit it it will bounce the same in the trk. Also if I’m backed into the dock I can feel it when the fork lift goes in and out of the trailer. I took to Peterbilt for a alignment to see if it was that but they told me they couldn’t do it due to 2 bad shocks so I took it home and replace all shocks including bunk ones still no difference and they said they didn’t think the alignment was the cause anyway cause I have over 100,000 miles on my tires and they are wearing perfect I am going nuts over this spent tons of money trying to figure it out just wondering if anybody else ever had this issue? Thanks. Here is a list of what I have done trying to figure it out.

king pins
Front spring bushings
Rear spring bushings
Cab mounts
Sleeper shocks and stabilizer bar
Rear end stabilizer bars
Front and rear shocks
Checked out frame and crossmembers dozens of time nothing out of the norm

 

Yes sorry I forgot to mention I replaced both leveling valves and set ride heights

 

It does it bobtailing way worse then when have trailer on

 

I was wondering this myself but Peterbilt said they didn’t think that was the problem I probably should just replace them

 

I replaced leveling valves and moved the valves up and down by hand and they lLinflate and deflate