Had the front right wheel bearing replaced and all wheels balanced. still shakes at high speeds though? any thoughts? the mechanic looked and said u joints were good and only the back left ball joint had play in it.

Check wheel balance.

could be a few things , wheel balance , wheel bearings , top / bottom ball joints , track rod ends , will need to be looked at by a mechanic to find the actual cause

Recently ballanced ? If they are steal rims they could be one bent if you have your tires rotated and its not as bad then thats it if it shakes at high speeds like freeway speeds then your car may need alignment and all the joints in the front end replaced along with the wheel bearings too

If it only does it when you are using the brakes, I would check the brakes on both sides.
If it does it without using the brakes, I would look for a bad tire on the front. One of the tires could have a broken belt inside the tread.
Could also be a bad wheel bearing on the front.

have the front wheels balanced

lol Make sure you wash the inside of your rims after you go playing in the mud. a small amount of dried mud will make your wheel shake at a high speed. It will unbalance your wheel.

Why drive side bearing could be a bad other.balance yes, tie rod could be bad.

You might take a close look at the ball joints on the front suspension/steering arms. I've had the same problem on another vehicle. Also you should check the front wheel bearings for loose play.

At what speed do you feel the shake and does it only happen when you apply the brakes?

check your tyres and wheel alignment and wheel balance if all that is good inspect your engine mounts for wear