Recently purchased a used Volvo S40.
Once on the highway, noticed front end vibration. Dealer said one rim was bent and tires were cupped. Tried to straighten the rim, but made no promises. Vibration still present.
Took car to a tire shop. Said two rims were bent. Moved the two bent rims to the rear. Still vibration.
We are willing to buy 4 new rims and tires. Should we also investigate wheel bearings and shocks? What sequence should our action take?
Take it to a shop know for suspension work and have them evaluate the suspension parts for wear. If the rims really are bent, you may also have bent suspension components. If the car is old enough, you may need new bushings. The only way to know is to have it evaluated by a good tech. It does not appear that either of the shops that you used can figure it out. You probably need to find a new one. Ask everyone you know for a recommendation and eventually a short list will develop.
BTW, what’s the age and mileage on the S40?
I had a bent rim on my car that caused accelerated tire wear and brake rotor wear. The vibration drove me nuts! Since I’d let it go for a while, the bent rim caused the other stuff. Fixed the other stuff first and made it better but it took replacing the wheel to finally fix it. Don’t depend on the mechanic to “fix” a bent wheel, especially aluminum ones. There are specialty shops that can fix your bent wheels but if you have more than 2 to fix, you can probably replace them all for the same price. Fix the bent wheels FIRST and then see if the other problems go away. If so, you are done. If not, check ball joints, tie rod ends and bushings and alignment. Don’t worry about the bent wheels damaging the bearings or struts but check 'em anyway with the front end inspection.
I agree with jtsanders that you need a thorough inspection of the front end. If the rims were bent in an impact, then other parts may have been damaged.
I think people have a misconception about what a bent rim is. They look around the edge of the rim for an indentation and if they find one, they think the rim is bent. What a bent rim really is is when the plane of the mounting plate is not perfectly perpendicular with the plane of the rim. Kind of like the difference with a capital I and an italicized I. ＩＩ
One way that this can happen is when you get new tire. To dismount the old tires, the first step is to break the bead. On a modern tire machine, breaking the inside bead is a blind job and if the bead breaker hits the wheel instead of the tire, it can bend it a little.
Other possible issues, if you’ve had a brake job done and the rotors were replaced, if anything got between the rotors and the hub, it will act like the wheel is bent when it actually is not. To check this will require removing the rotors.