It seems like something happened when they were building Time Traveler that caused that one section of ride to get really bad. It's definitely a jarring bump/ jolt, and it doesn't feel good. Not sure what needs to be done to fix it exactly, but it does need something done.
No need to replace the whole coaster though- just fix the one section and give it a nice refurbishment as a whole. It's a good mine train coaster. There are a few I like better, but if you're in middle America then it stands out above almost everything similar within a 10-12 hour drive.