Greybeard14

Hi fellas, hope I could get some opinions on my shudder issue on my stock 2013 XLT s-crew 5.0 w/ 48,000km. I'm getting a misfire/shudder feel under constant or light acceleration at speeds around 30-60 km/hr (not throwing a code), almost feels like the engine is lugging. Seems to disappear with added or reduced throttle. It's got that feel like you're running over small bumps in the road...which combined with running over small bumps in the road, makes it an awkward thing to track down.

I had gone for a drive with the dealership shop foreman for another issue and he noted the herky jerky himself although the laptop hooked up to the truck didn't show any misfiring then, or during the last 10 run cycles. I understand it could be an elusive faulty coil causing a misfire but not throwing a code, but I feel like it is transmission related.

Something I have also noticed with this truck is it seems to occasionally do a half-shift under specific increased throttle, that is it doesn't shift down to 4th from 5th, but the RPM's jump up a few hundred. Is this the torque converter unlocking? With these newer trucks where you don't touch the tranny fluid for an ungodly amount of mileage...I can't change the fluid and filter with the slip additive.

Any advice on where to start would be helpful.