had a transmission replaced in my 97 ford taurus, 120,000 miles. I notice now when i turn right it will sometimes make a noise and i will feel friction in the steering. I drained the fluid and replaced it with some lucas oil for the problem. seemed to fix it but now it's back. I have a few questions?

1. Did the mechanic have to mess with the rack and pinon when replacing the transmission?
2. Is it hard to replace, I have no problem doing things unless it's an internal problem or something, does it take special tools or alignment?
3. Do you think it will be safe to operate in this condition?
4. Could something be out of alignment?

The reason I feel it's the rack and pinion is the mechanic that did the transmission told me so. He's a ford man I feel he knows what he is talking about.

Thanks