Hits the steering wheel from 140 km / h - Toyota Caldina, 1.8 liter, 1998

In recent months, he often began to ride 200 or more kilometers. So here, at speeds over 140 km / h, the steering wheel vibrates quite strongly (beats, but does not fight yet).
The car doesn't pull anywhere. No visible damage found.
Tires Michelin Energy Saver 195/65 R14

There is a little background:
in the spring of 2009 I bought new ones (3200r 1 cylinder). in July struck the front right. The disk on the inner contour is slightly bent, the rubber is in the trash :(
I put a normal wheel forward, I roll the disk (1000r).
I put a set of old Nokian NRHi 185/65 R14
on the rear axle . than I bought in the spring.It is worth noting that only two Tomsk firms agreed to bring: Koleso (for 4600r) and Premio (for 3950r).

Accordingly, the summer season of 2010. I drive a full set of Michelins. put the newly brought wheel back (front-wheel drive cars)

In July I noticed a beating.

Where to begin? gathering / entertaining, balancing or rolling the disc (discs)?

I want to spend as little as possible because I will sell soon.

comments like "forget it" can not work and not write. Thanks for understanding!