Hi
I am happy the chiropractor helped your TMJ. Ask him if he could work on Longus Colii and Longus Capitis muscles in front of your neck. With whiplash these muscles get a lot of stress and they can stay chronically contracted for years after the accident. Usually back of the neck gets most of the attention and the front is ignored.
Do not worry about cracking sound during adjustment you can get used to it. I have been adjusted for years and it doesn't bother me now at all.
bociak