How to Spread 2-3 from 1-2 shift. Why only Two turns?

biggy238

biggy238

Active member
Joined
Aug 3, 2008
Messages
10,994
I have a couple of questions.

I've been reading for days, google searches, here and cummins forum.

My DTT 47re in the 96 was soft shifting into 3rd and then not coming back down at a stop, even with a new governor pressure sensor and solenoid. I had also installed a 120ohm resistor. I posted another thread with some pressures that I will have to dig up again.

I adjusted the TV cable today, and got my shifts back, but they were softer than they should have been. I came back and adjusted my line pressure. I was sitting on 130 WOT before so I went 10 turns. I have to retest for where I ended up.

I took the Throttle valve screw in two turns as directed by DTT and BD in their adjustment directions. I've run just under 100 miles. My shift firmness is back where it should be, but part throttle I'm shifting 1-2 at 15mph and 2-3 at 20mph. Lockup is at 45mph with this throttle input. Why only two turns on the screw?

I bought an adjustable voltage reg, LM317T to feed the gov sensor. Does it need a 12V supply, or does it run from the 5V that the PCM provides? IT would be better to run it from +BAT but I'm afraid it would cause a Voltage High code from the PCM?

Any help is greatly appreciated. I almost have it back to where it needs to be.
Kyle
 
The governor solenoid runs on 12v from 0 to 1amp according to the factory manual.
 
I hadn't thought about that, but it isn't a bad idea either.

I guess I should explain more. If I use the voltage regulator for the governor pressure sensor supply, I can either use 12V input from battery and the reg will knock it down (Not is series with the PCM), or I can use the 5V already run to the trans from the PCM, put the reg in series and then the reg should cap to whatever The pcm sends to my chosen output.

If I use an external source, I'm affraid the PCM will see an open circuit on the 5V supply and throw a code. I can;t find instructions for the DTT or goerend version of this online. Having that could answer some questions. I'm sure some other guys would like to know how to build one for cheap also. I have about $5 tied up in radioshack parts.

How far can I crank in the Throttle Valve screw and not cause a problem? I keep finding that past 2 turns is not good but no explaination of why.

Love the Giada (sp) gif
 
Be very careful with he 5v feed from the factory. It's for the sensors only and can't support much current. Definitely not the current required for the solenoid. You need a PWM signal to feed to the gov solenoid so you can adjust it's duty cycle. At 0v, the transmission will see no pressure and it will limp. At 12v, it will be 100% duty cycle and you'll never make it out of first gear. It needs to ramp proportionally to the speed and TPS inputs.
 
joefarmer said:
Be very careful with he 5v feed from the factory. It's for the sensors only and can't support much current. Definitely not the current required for the solenoid. You need a PWM signal to feed to the gov solenoid so you can adjust it's duty cycle. At 0v, the transmission will see no pressure and it will limp. At 12v, it will be 100% duty cycle and you'll never make it out of first gear. It needs to ramp proportionally to the speed and TPS inputs.
Click to expand...

So what about guys that have potentiometers in place of the TPS? Gain on the circuit only from the speed sensor?
 
Its soft down shifting. I can't feel them
Im not sure who mis spoke but I never intended for anyone to think im feeding the solenoid. Only the sensor/ Transducer.


I just want to knock down the sensor supply instead of using the resistor


Oh really?!
 
So what's up with only being able to adjust the throttle valve screw two turns guys?

Oh really?!
 
Yes. Why my dumb ass didn't express it that way im not really sure. But yeah, its shifting out of 1st at 15mph and then out of 2nd at 20mph.

Oh really?!
 
You can turn throttle valve screw as much as you want , it will raise your light throttle shift point for 1-2 and to avoid stacking shifts you need to change the 2-3 spring in valve body accordingly.
 
Lavon,
Does valve body wear account for it stacking shifts over the course of about 100k? The springs should have been upgraded from the get-go as it is a dtt vb
Oh really?!
 
I was thinking you can put a tv spring out of a V10, to move the shifts out.
 
And this is gonna raise the governor pressure needed to shift for 2-3

Oh really?!
 
You must log in or register to reply here.
Back
Top