After installing my 3.5” lift the front of my jeep shakes up and down like a stutter for about 1-3 seconds when i hit speed bump or sewer grate. I think its the springs but I’m not completely sure.All bolts have been checked twice to make sure they’re properly tightened. And its not DW.

 

This will either sound ridiculous (superstitious), but torquing versus unbolting and then torquing?

Tires all aired up correctly, balanced?

I have 3.5" of lift as well. You have 35s?

 

If it's not DW, I would guess you have a bad shock. Unbolt the lower shock mounts, tie them out of the way and go for a short drive. See if or how it changes and report back.

 

Do you have a raised front track bar and DL flip? It may be the bump steer. I had a similar effect u described. It seemed to be more prominent when I hit bumps that crossed both tires like speed bumps and bridge grates, etc. Do you notice the steering wheel kicks left when u hit bumps. If so it may be bump steer.