smarty s06 tnt r
 

Hi guys i have a prblem with my truck hitting 4th gear when the overdrive button is turned on. Its a 2007 5.9 and when Im truck pulling i cant get the truck to stop shifting into 4th gear. I pull in low range drive with the overdrive off button turned on. I put the programmer on high rpm so it turns 3500 then shifts. Will hold 3rd gear for about 3 seconds and goes into 4th gear. The only way to get it back into 3rd gear is hit the towhaul button twice and it will back shift into 3rd. By that time its to late and cant get no distance or momentum out of her. Any info on grounding out the overdrive solinode would be greatful. Not sure if that is the answer but willing to give it a whirl. Thanks guys.