Need some advice. I have looked through alot of threads but haven't really seen my specific issue. I have a 2004 4x4 Quad Cab 5.7 Hemi w/5speed auto trans., 83,000 miles. I have the 3.55 gears and running 315 tires. Yeah, I know sucky gears for these taller tires ! The problem I have is when towing a fairly light trailer, 2500lbs aprox., at highway speed, 70mph, the trans seems to "hunt" for the right gear to be in. It constsantly downshifts and upshifts. Now with the tires size, my speedo is reading 63mph when I'm traveling 70mph. I have been considering buying a Super Chips Flashpaq. From what I've read this will help the trans at lower (acceleration) speeds, but maybe not help my issue. I dunno, maybe when the speedo is corrected it will help ?? In all honesty, even with the taller tires, acceleration is still pretty good. It doesn't seem to matter much if I use the tow/haul mode. Still does it, just turns more RPM.

 

Just put the truck in tow/haul mode or use O/D off feature. This will stop it from shifting into 5th. Also, it will prob get you better gas mileage since you have such low gears with a tall tire. You wanna be at 2krpms at cruising speed.

 

Using the tow/haul mode does not help...it still does the up/down shifting thing. I cannot turn overdrive off, I don't think ? Like I stated, this is a light trailer..I would think I could pull it easily ??