New member here with an issue.
I have an intermittent issue with my truck when driving at or near 50mph and faster. The problem occurs when I’m driving on a road or highway with elevation gain. The transmission seems to jump between 4th and 3rd gear back and forth while driving ‘up’ a road. If I turn the Over Drive off allowing the truck to run at a higher RPM the problem is nonexistent at any speed. This leads me to believe I do not have a transmission problem and probably more of a electrical/sensor issue. The frustrating part is I receive no error codes from the car. I’ve replaced the TPS sensor, cleaned the throttle body, and recently replaced the fuel filter and added fuel injection cleaning solution via the gas tank. I’m at a lost here so any advice would be greatly appreciated.
truck can’t make up its mind on which gear it wants to be in? it sounds normal to me. your driveng at a speed where you start up a grade and it needs to drop a gear to maintan speed and as you level off it ups shifts again . you can drive a little faster or take it out of overdrive
Big Marc - Thank you for your reply. I understand what you mean but there is a true problem here. I have owned my truck for 6+ years and this has now just started. The ‘gear skipping’ happens repeatidly back and fourth. Not your normal up and down shift.
Is it possible you have a misfire problem? When a coil(s) go bad (you have COP’s, meaning a coil on each spark plug) you will get a misfire and it is most noticeable upon light acceleration. Before the computer registers a “code” the misfiring has to be pretty bad - so at the start of this problem there often is no code.
If you do find it to be a transmission shift issue, it is likely the lock up torque converter is the culprit.