2000 Ford F-150 - Chatters at 45

When my truck is between 45 and 50 it seems to chatter a bit
Then going 50mph it is fine,if I take overdrive off around town
I have no problem

Offhand I suspect a problem with the torque converter lockup. Start by checking the transmission fluid but I doubt it’s that simple. Bring it in to a good independent transmission shop for a diagnosis.

1 Like

Try changing the transmission fluid and filter. It sounds like a rumble strip torque converter shudder which is pretty common with Fords. Worst case scenario is a new converter but I would not fret over that at this point.

Every Ford I’ve owned that developed this shudder was resolved by a simple fluid change which I normally do at 30 to 40k miles intervals. In the event I let a 30k slip by me I usually get a reminder around 35k miles when the transmission starts to develop very subtle signs of this problem.

If the transmission fluid/filter change doesn’t work. then try this in the transmission fluid.

https://www.lubegard.com/products/isf/

Tester