Camera won't shoot - with one lens only

[phkc070408]

I have a Canon T5i and 4 different lenses.  One of them is the Tamron.  I've had this lens for 5 years now and it's worked flawessly until last week.

I put the lens on the camera and placed it in auto-focus mode.  1. It won't auto focus.  The AF goes to the one extreme and back to the other, passing over the proper AF setting.  It then realizes that it can't find the AF point and stops searching.  Also, when I then press the release button fully, it won't shoot.  It DOES shoot when in manual focus.

I cleaned the contacts on the lens as well as the camera.  I als placed the camera in manual focus mode and adjusted the focus from one extreme to the other baxck and forth 3 times.  I did the same with the zoom, zooming fully and then wide open back amd forth 3 or 4 times.  This was recommended by Canon.

Any help would be appreciated.  Thanks.

[phkc070408]

I don't know if it's linear or circular, but it's this one 

However, that did not correct the problem. I sent it off to Tamron for repair and was told that they are going to

1. Repair AF Mechinism.

2. Replace Focus Gear Assembly becasue it is stripped.

So hopefully it comes back working as intended.  Thank's for all of yoru help.