2000 SR5 auto. SS1.2 current lift. 33in tires.
I've googled and googled, but seem to only come across high speed issues. I've got a shudder when going over small road bumps, mostly at low speeds to about 45 or so mph. I feel it in the floorboard, but not in the steering wheel so much. It's not brought on by braking, just by certain road conditions. It feels like something is loose, but as far as I can tell nothing is. If I had to pinpoint a location, it feels like front driver, but I don't rid passenger to know if you can feel it there too.

I've recently done the steering rack bushings, inner tie rod replacement and a check of the outer tie rods.
The upper ball joints are the JBA older style and the boots look good. I even put some extra grease in there, but no real change. These are about 2yrs old.
The lower ball joints look fine- no grease and no cracked boots. These are probably 4yrs old with 2.5yrs on the lift.

New/different tires did not make a difference.

I did the tire test before I changed the tie rods and the ball joints did not have a lot of play. However, I have not pulled everything apart to really take a look.

I picked up some new lower control arm bushings, but I'd really prefer not to do this if it isn't actually the issue. The control arms are factory and she stays in alignment. A recent alignment shop made no mention of the bushings being bad. Is there anyway to really check these? I've heard the pry bar test is insufficient. Anyone have similar symptoms before changing them out?

CV's are napa's and are about 2.5yrs old, swapped in shortly after the lift. They don't make any noise and the boots look fine.

I guess the other possibility could be U joints? Shocks?

Anyone have input for me before I throw more parts at it?

by shutter you mean it seems choppy?

because what you describe to me seems like a stuck break caliper? they can start out like this, only happening every once in a while. it can feel like a vibration when then caliper is slightly sticking and pads/rotor heat up and kind slip causing a shutter like feeling.

I would jack the front up and spin the wheels, does once wheel drag? if it does you might want to look at the front calipers.

Thanks for the reply.

I wouldn't say choppy. When I think of choppy I think of that warped rotor feel. This is more of a loose shake. I'll still check the brakes as I was suspicious of my calipers sticking due to uneven pad wear when I did my brakes a ways back.

Finally had some time to pull the driver's side apart. Tie rods and lbj were still good. Got the lower control arm disconnected from the ball joint and shock- seemed like it was in good shape. Some up and down movement, which is normal, and no discernable lateral movement with a pry bar on them. Since the shock was mostly out I figured I pull that and take a look. I can't remember how much play the bearing (lower shock mount heim joint on radflo 2.0) had when I installed them, but there was quite a bit now. Even installed you can wiggle them what seems kike an eighth of a turn or so. Took a pause to Google it and it the Nissan guys are always going on about how these bearings need changing and cause similar symptoms to what I have. I ordered two new FK Com10t spherical bearings and will update again after I install.