I got the same rocking motion on mine! It will even fall back if i put too much pressure back on the seat without using the lever.

If i got some time this weekend i will check it to see if i can find a reason for it and a solution. I will let you guys know!!!

 

I had that problem when I first got mine. Power seat drivers side. The handle felt like it was going to break I had to pull it so hard. I noticed that it didn't work too well if I had the power seat totally dropped to the floor. It would work much easier if I raised the seat just slightly. Now there's no problem with adjusting it. But I do feel the seatback nudge a bit further when I lean hard on the rout side. I didn't notice any issue with the passenger side.

Where did you buy it? Private owner or dealer? Any warranty on it? If it was a big place like carmax or a reputable dealer they should make sure most things are functioning as close to factory spec as reasonably possible.

 

Have the same occasional issue with mine as well - '06 QC Laramie. Power seat driver side - slight shift or rocking upon braking usually. The recline mechanism seems to work smooth and the shift is minimal.

First thought it might have been related to the adjustable lumbar support snapping - adjusting wheel on side of seat just spins freely at this point. Anyone deal with that issue yet?

 

mine did that once also. BUt i just stopped puttin too much pressure on the back.. bbut it does rock

 

I had the "rocking" issue on a tahoe. The dealer told me in that case that there are plastic bushings in the power mechanism that wear. When they do the seat will slightly rock. I am noticing a very slight rock in my seat now. I wonder if it is the same issue as my tahoe. I might have to pull the seat and investigate.