Transmission slipping or shuddering between 45 - 55 mph

Race · #1 09-17-2008, 03:43 PM

I have an 04 FX4 Screw with 58,000 miles on it. Ive recently noticed what feels like the transmission skipping or shuddering while going 45- 55 mph. It only does it while driving at that speed. If I'm slightly accelerating say upto 65 i cant feel it.

What do I need to do to fix this?

Thanks
Race

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glc · #2 09-17-2008, 03:45 PM

Are you sure it's not an engine misfire?

When was the last time you changed the tranny fluid?

Race · #3 09-17-2008, 04:31 PM

I'm pretty sure its in the transmission. Its a slight tugging or jerky motion and it only happens if I'm driving a steady 45- 52. It doesn't do it if I'm accelerating or at any other speed. I haven't changed the transmission fluid yet?

NTXRockr · #4 09-17-2008, 05:14 PM

I've had mine do that to me every once in awhile. It almost acts like it's hesitating or is in between gears, and when it does drop down a gear it jerks into it.

Someone posted one time that it's a PCM issue, that in that speed/power band the computer gets confused and doesn't know whether to go into OD or stay in the current gear, etc. If I remember correctly there's a dealer fix to where they flash the PCM with the update, but I haven't done it and can't remember which post I read it in. You might try searching for it as it was about a month ago now that I think about it.

glc · #5 09-17-2008, 05:17 PM

At 58k you need to go get the tranny fluid changed. I'd recommend a place that has a fluid exchange machine so you can get it ALL out, unlike with a simple pan drop. There's no drain plug on the torque converter.

Those are still possibly symptoms of a low grade misfire, but go get the tranny serviced first.