Ok so my front tires are real low tread and they have worse grip. I get that. But after doing some steering work and getting it aligned the shop went " hey part of the wheel shake is due to your badly worn tires. You should buy some new ones we have right over here."

Is that just them trying to sell me tires or does that really affect my wheel that much?

 

I guess it could effect it if they were worn uneven

 

uneven wear can cause ball joints and tie rods to become loose after a long period of time. i dont think its tires. put your rears on the front if you can and see if it does the same thing. if so then the alignment shop did an alignment on old worn out steering components

 

rears are bigger then fronts

 

Yes worn out tires can cause shakes. After the tread starts to wear down, the tire it self gets lighter and needs to be rebalanced. And depending on how hard of a life the tire has had, it can start to come apart (called tread seperation) and cause some hellacious noises and vibrations. At 2/32 of an inch of tread left, the tire is considered unsafe and should be replaced.