2.8l v6.....when i press my brake at approx. 35-40 mph my car feels like its tryin to shake water off like a dog

it doesnt happen at just 35-40 mph, sometimes a little lower but mostly around that time

tire balancing? drive shaft? brakes?

any help is appreciated

 

With my very limited knowledge of cars, I can say that it might just be that your brakes might have been tightened too much. My Cavalier does that when I going fairly slow and then hit the brakes, the ABS will go nut.

 

warped rotor possibly

 

i was thinkin warped rotor as well, i took it to the place i bought the wheels from thinkin i might be able to con them into fixing it for free sayin they over torqued my lugs but that didnt work lol so i took it to a shop close to my house. the rotors werent warped hardly at all but i had em turn them neways. well the car didnt shimmy when i pressed the brake nemore but i got goin down the road little ways to about 45 mph and it started shakin hardcore without me pressin the brakes so i took it back. they said i had a bad tire in the front so we switched the suspected one to the rear and the rear started floppin around. the mechanic then told me i just had a bad tire. welp by this time i was pissed b/c the wheel guys told me they couldnt help. so i go back to the wheel place and demanded them fix or replace their screw up. so they took it off and put it on the balancer and it was off 1/2 ounce. they fixed it for free. the end.....yay

 

Good for you, now you have a nice smooth running car.

 

good thing it was somethin easy