My 98 e300 is sometimes hard to turn to the right when it is cold, but turns fine to the left. It doesn't do it every day, but it is much more likely to do it after the car has been parked overnight or during the winter months. It only does it in the first few minutes of operation. I talked to the service manager at the dealership about it, and he said it was probably caused by a sticking valve in the rack. I could have them put in a seal kit, but a rebuilt rack would cost about the same. He said they've had good luck using the new synthetic ps fluid for problems with W210 racks (Pentosin CHF 11S, $20 per liter). I flushed the system twice and the fluid that came out was dark and murky. I put the synthetic in, and probably reduced the frequency of the problem to half what it had been. I wasn't satisfied to go through another winter fighting it though, so I thought about what would make the sticking valve work better. I'll probably get scolded for this, but I put in a little NAPA/CRC power steering system seal conditioner that is supposed to be compatible with all fluids. This winter the stiffness has been even rarer, and I can power my way past it, where before, I had to turn the wheel left a little to make the stiffness go away. I figured if I needed a new rack anyway, I didn't have much to lose. No problems so far.