Hi guys, new to this forum, but regular {performance} forums are not much of help, so I came to you.
My 2006 focus zx3 that i got new has been having some vibration issue. It was lowered, yeah I know I was dumb at the time, but now is back to stock. After lowering, and maybe before I had this vibration that is more of a rattle, or more like my tires would be out of balance. It is felt in the steering wheel more like a back and forth motion. Also in the shifter manual, i get a knock sometimes and also the same vibration. The vibration is not from the tires, wheels and all that since it stays even after I change tires, wheels and all that.

Now things that were change by me and the dealer:

Dealer: engine mounts, all of them, pads and rotors, some other parts, that are not related.

Me: springs, about 1.5 inches but when back to stock. Now I have new shocks(tokico), new strut bearings, new stock wheels and tires, new brakes front and back, new sway bar endlinks.

The knock in the shifter tells me it might be something in the engine mount, the back one.
The steering wheel vibration seems like a bushing is bad, or something is loose but nothing presented like that.
Now I also have a griding noise coming from the bottom of the manual trany wich the dealer tells me all is ok, but I find it odd, could that produce this things at higher speeds? Someone told me it might be the throw out bearing rattling.

 

Might check for loose subframe mounts.

 

Have the wheel bearing checked. the same thing was happening to my wifes car. I heard they were notorius for bad wheel bearing. They are fairly enexpensive.