35" Tires And Overdrive

Took a vacation drive to Austin this summer not long after installing the new rims/tires. On the day I left my hypertec Speedo calibrator came in and did not install.
When driving 75/85 the cruise had a hard time holding it in OD after climbing any small hill. When i got to Austin I installed the hypertec and it made no difference. The way I was able to keep it to stay in OD was to move the shifter to manual, bump it to 6th then it had no problem staying/going back into OD after downshifting.
Any vet thoughts would be appreciated.

 

Have you thought about re-gearing? The hypertech won't affect anything here as far as RPMs or shifting. All it does it take the MPH input the vehicle is giving it and covert that to the MPH you see on the dash based on what tire size you entered in the software. Although, it should also make your odometer more accurate.

 

Yes I believe the hypertec is doing it's job (no tickets), just wonder why when it's in Manuel shift it will go back to overdrive no proplem. As for re-gearing I think that 4th gen will be out soon.

 

My truck does that too occasionally when I shift out of D and put it into S6. Not every time, though. When I say re-gearing, I mean going to a 4.88 gear ratio. That is likely the best way to solve your issue of your truck dropping out of OD. Not exactly cheap, though.

 

Roger that, but it will go back into OD when in manual when using cruise.

 

Roger that on the 4.88s, would have done with a SC but the wife keeps me in check.
If after it downshift for incline it will not go back to OD unless you have a slight decline, take the cruise off or putt it manual s6.

 

Same exact situation I had rolling north and south the length of Illinois with the lifted truck I owned. Constant in and out of OD or just holding in direct with any puff of wind. I was able to do the same bump shift to get it to settle down a little. I have no solution to offer, I traded that truck, just noting you aren't alone.