on my 04 screw 4x4 5.4 Automatic trans, I will be driving down the highway around 70 mph. when I slowly step on the gas just enough for it to downshift out of overdrive every now and then I feal a huge shutter or vibration. It feals like ran over those stripes on the side of the highway that make a big vibration and noise. It almost feels like when you upshift in a standard trans into a gear thats to high and the engine cant keep up. But it only happens when the trans shifts from od. I cant figure it out.

 

Did you ever find a solution to this problem? You pretty much described word for word what my truck is doing. Any info. would be greatly appreciated. I am going to have my truck scanned tom.

 

ttt

 

First thing to try is a complete trans fluid change. If that doesn't do it, investigate the secondary ignition. It could be a bad coil, boot, or spark plug.

 

Did you ever find out the problem???

my 97 is doing exactly that at low rpm, low speed , when shifting OD.

 

my 98 does the same thing

 

Just adding my comment adding my identical symptoms.

 

mine did the same thing acted like it was trying to shift down but just couldn't do it i did the plugs and cops and it doesn't jerk or shudder any more but it still shifts into od at 65 - 70kmph and wont shift back down unless i press the pedal at least half way
but ya change your cops its most likely what the issue is

 

Guys, hey does anyone have a solution for for the problems described above regarding shuttering when down shifting from overdrive? Have tried many things but nothing to solve the problem.

 

Its an engine missfire-most likely..

 

Is second the low grade misfire comment. Not enough to throw a code but enough to feel.

 

Hey, Im not a mechanic, but does that mean i need to have my sparkplugs changed?

 

Maybe.

 

Anybody think it could be shift selenoid problem, torque converter,engine of tanny mount? I would think a COP or plug would be at any RPM . Torque converter going from lockup to unlock would do that too. Hell even a U-joint could do some weird stuff like that.

 

Low grade miss fires generally are not constant its an intermittent miss. When I've had one it would happen in OD and it can feel like a transmission problem its frequently misdiagnosed as a trans problem usually by the owner. Make sure your engines running right before you haul it down to AAMCO For the big dollar overhaul. If you haven't tuned up lately its probably time..