This one has got me stumped. Last night I put a new set of 2001 S class wheels on my W140. They look great but the car has started to pull hard to the right. I switched the old tires (not really old, less than 8K miles) onto the new rims and balanced. The tech was very careful to put the tires back in their original location on the vehicle. The car drove perfectly straight before the switch so I can not figure out why it has started pulling. There is no irregular tire wear and I checked the tire pressure on all the tires and it is at 35 PSI all the way around. Any ideas on what would make this car pull? Also, if I need an alignment does it require a four wheel and what is everyone paying for this service?

Thanks for the help!!