I had a very strange thing happen tonight and I'm not sure what it was. Hoping to find some advice here. 2006 Dakota Club Cab SLT 4x4 6-speed manual, 77K miles. I was in 3rd gear and felt what seemed to be a washboard road in the drivetrain. Except the road was perfectly smooth. This continued for a few hundred feet. I let off the gas but it continued. I got back on the gas easy and it cleared up. Didn't happen again the rest of the way home, another 5 or 6 miles. It felt like a shudder that would start/stop, start/stop, rapidly. The only thing that comes to mind is the pressure plate wasn't completely engaged with the flywheel. Clutch has normal movement and foot pressure - it didn't feel different like the slave cylinder was failing. I thought it happened a few days ago, but it was for a very brief time and I thought at that time it was the road surface. Now I think it was the same thing as today. Any thoughts? It is 13 years old with original clutch, but I don't hot rod it, although I've been known to get on it every once in while. Thanks!