Thanks for coming back to me. My seat goes into the correct position but there is no click or clunk like there used to be. But there doesn't seem to be any catch for this to happen. It merely sits in the correct position. Maybe my back rest is not as snug to the base as it used to be as i took this apart too. Everything has been assembled tightly and correctly but no cllick or clunk. Can you see a catch or latch for your base to click into ? I'm concerned my base cushion is not secure without this clunk.mine sometimes takes a determined effort to get it to "clonk" shut, I just put it down to newness but I remember my old T5 had much the same problem until I clunked it too hard one day. Never had a problem after that but something broke., some plastic catch or latch.