2002 Chevy Trailblazer Front end vibration

There are many stages of vibration. The most common is in the steering and USUALLY a steering dampner will correct this. However, your description is not real defined and until the technician actually experiences it, it cannot be properly diagnosed

bent tyre or dish rim, check tyres and rims and speed balance would help.

Does the shake match tire rotation or drive shaft rotation speed? If it's at tire rotation speed,have the new tires been dynamically balanced on a brand name motorized balancer?Re balance them that way.If a wheel weight has come off you will have a shake.You can also rotate the tires from front to back and see if that helps.Also,brake rotors can be out of balance and even with a perfectly balanced tire,the rotor can throw the balance off.

Replace the right front wheel bearing

I'm thinking tires. Have the balance
checked.

Let me see know at 45 miles per hour a vehicle usually shifts gears into the highest gear so could it be the torque converter hanging up and not shifting quick enough or maybe its the U joints. Have the transmission fluid checked for proper level and color.
Here's a small test for you when your accelerating up to 55 miles per hour try letting off the pedal at 44 miles per hour and then reaccelerating up to the 55 mph and tell me if it`s smoother if it is then chances are that it`s hang up on third gear. There's also a electric sensor located on transmission that assist shifting it`s usually controlled by the engine timing.
One more thing did the repair man check to see if the tires where directional tires if there not put on right it could cause vibration and early wear out .Hope i helped you.

The drive shaft needs to be replaced.its slightly bent or damaged.Check end float on both drive shafts for excesive movement.Also check for lift in the driveshaft gearbox bearings.Hope that is helpfull.good luck.

Does the left front go click, click, click on tight slow turns.

sounds like tie rod ends with the shaking.check struts and sway bar links on the snapping. hope this helps you.

Check wheel bearings on all four corners and check front ball joints and tie rod ends for play.