Since rebuilding my trans and VB, I've had an issue with shifting in my truck. '96 47re w/ DTT master rebuild kit and VB kit. All sensors and solenoids replaced with new at the time.

I worked with DTT over the phone with the 1-2 and 2-3 shifting, but was told the 3-4(OD) shift can't be cured, since it's done by the PCM. At the time, I lowered the line pressure some from 78psi to 72-73ish at 750rpm in gear and adjusted the TV stop and TV cable enough to better the 1-2 and 2-3 shifting, but still have 3-4 shifting too early.

I've checked TPS voltage and adjusted it in increments up to 1.5v at idle with no effect. No Check Engine light has come on for overvoltage or out of range. If I cut anymore on the TPS to adjust any higher, there won't be anything to bolt to.

I still have 3-4 shifting as early as 25mph, but mostly 30mph under light throttle. If I had no governor spring kit, it might be fine, as I'd need more throttle for accell and the shift would probably be delayed enough. I didn't seem to have the issue with the governor spring kit and the stock trans with the TV cable pulled about as tight as possible. Maybe I just didn't notice it though.

Is there anything else other than a potentiometer that I can do? I didn't install the DTT resistor box thing that keeps you from having 3rd gear starts, because I don't have that problem. Would that box effect shifting too? Would it help?

I'm not sure about these trucks, but I know a lot of the other Chrysler vehicles learned minimum TPS voltage at key on, then uses that to determine position from. Minimum voltage is not a set voltage that never changes and is stored in the PCM for those. That's what it seems is going on with my truck when I adjust it higher and higher.

Thanks

 

can 3-4 be shifted manually or do u only have a tow/haul button?

 

mines in od by forty with light throttle, but have 4.10's. usually drive around town with od off gets annoying kicking in and out, but figured thats nature of the beast. keep posting i'd like to change how mine shifts also.

 

I have an OD on/off button and it works fine, but VERY aggravating to use. It shifts to 3rd and then locks up hard, lugging the engine slightly at 30mph. Then when I push the button to shift into fourth, it has to unlock in 3rd before shifting to 4th then lock back up at 48mph.

I normally keep OD off in town also if speeds are slow, but 45-50mph speed limits and 3rd gear buzzing at 2000+rpm are annoying and not fuel efficient I'm sure.

 

Anyone have an idea? Will the resistor trick for PCM line pressure effect shifting any?

 

Just to update because.

The DTT adjustable pot to cure 3rd gear starts doesn't affect any shifting points as far as I can tell, nor did it cure my 2nd gear starts, then kickdown to 1st as soon as I start rolling. Adjusting the TV cable tighter seems to help the 2nd gear starts, but of course raises 1-2 and 2-3 shifts...