Engine/Transmission (1994 - 1998) Auto trans shifting issue

[Rosshatfield]

I have a 95 with an automatic. It does not want to kick out of OD when I am at cruising speed. It is frustrating when I am pulling a hill or need to pass. If I romp on it, it kicks down for a second and then locks back up. I have tried adjusting the TV cable back. I like the way it shifts now but it still has the same issues with OD. Could it be the OD button? TPS is brand new.



Thanks,

Chris

 

[Joe G.]

Is it the OD or the TC lock up? In other words, does the OD light turn on and off?

 

[Rosshatfield]

The TC locks up fine and stays locked. The OD light is acting normal.

 

[budctdca]

its probably not the overdrive switch because to my knowledge all it does is prevents the overdrive from happening and allows the tc to lock up in 3rd gear, i have seen some autos that have been used alot that have the tv cable getting stretched and losings its tensile strength. you might want to look into getting a new one, which might help. because the 12valves are heavily mechanically controlled, i doubt it is electrical. whens the last time you got the bands adjusted? hope this helps



luke

 

[Joe G.]

The way it should work is that when you kick down it should unlock the TC then drop out of OD. The TC should not stay locked during the shift out of OD. Then when it shifts back to OD it will lock up the TC after the shift. That's the way a stock trans is supposed to work. I'm not sure from your reply that it is doing that. The OD light is not controlled by the OD button. It is turned on and off by the PCM when it shifts in or out of OD in response to pressing the button. The button is a simple push to make, lift to break kind of like a door bell button. The PCM keeps track of the desired state of OD lock out and controls the light to indicate that state.



If the PCM is operating correctly then your TPS voltage may be too high. It's usually too low on these trucks. The kick down (TV) cable lever on the trans should have about 1/8" of movement left at WOT. Did you replace the TPS in an effort to solve this problem? Are there any modifications to the transmission control circuitry?

 

[Rosshatfield]

I did recently replace the TPS becuase it was kicking in and out of lockup. The problem I am having with it not kicking out of od when trying to pass or climbing a hill is something that it hase been doing since I bought the truck. I did adjust the TV cable abour a 1/4 inch towards the cab. I shifts a little quicker and cleaner but still won't kick down when I am cruising and need to accelerate quickly.

 

[Joe G.]

I don't know what you mean by "toward the cab". The adjustment depends on the position of the lever on the transmission not the engine end of the cable. You don't want any slack so that the throttle moves before the lever does. The adjustment that I use on my '95 as recommended by Bill K of DTT is that at WOT there is about 1/8" of movement left in the lever. The lever controls pressure in the VB which controls shift points.



The ideal idle voltage for the TPS according to the service manual is one volt + or - . 2 volts. Usually the voltage is about . 5 volts. The service manual method of adjustment will just mess up your throttle linkage adjustment before the voltage is correct. Usually a 47RH transmission will shift too soon if there is any wear in it.



If your '95 is stock then a kick down at cruising speed (60+) will just make more noise without a lot of acceleration.

 

[Rosshatfield]

The TV cable ties into the throttle linkage at the pump. Where the cable runs through the bracket the TV cable is adjustable. There is a release button that allows you to run the cable forward or backward. Pull out towards the rear of the rear of the truck, it makes the shifts later and firmer. Push in towards the front and it makes the shifts smoother and earlier. I do need to make sure that everything is good at the transmission, but I was not able to check at the Trans because I need another set of feet. As far as kickdown goes your right it only makes a little difference in acceleration, but its better than nothing. Rightnow all it will do is kickdown for a few seconds and then the TC lock back up. Thanks for your imput, I am just learning about my Dodge. Used to be a ford guy.

 

[Joe G.]

I use a stick and the power seat to push and hold the pedal.



The adjustment at the pump actually changes the length of the cable housing. The cable does not move. The pointed part of the cable housing moves in or out of the lock held by the release button.



It will accelerate a little then it starts to hit the defuel point on the governor for a stock pump. Then it starts to die. When mine was stock I experimented a little. The acceleration when the RPM is below 2000 or so is not as dramatic, but it actually gets going faster sooner if it does not kick down. Anything above about 2000 is going off the good part of the torque curve for a stock pump. My pump has some mods. The engine will pull hard to about 2800 and is still pulling at 3000 but that is about it. If you want more than that you will need to install a GSK. Stock it will be getting weak at 2400 and will defuel somewhere between that and about 2800 depending on the pump. Fortunately, it's cheap and easy to get a lot of power out of one of these pumps.



The 47RH transmission is sometimes a PITA to get adjusted right.



You might be interested in this thread in this forum:

https://www.turbodieselregister.com/forums/showthread.php?t=130979

 

[ronco]

Rosshatfield,



One more item to note. My "95 auto will not down shift or unlock the converter above 60 M. P. H. I have to be below that speed for the P. C. M. to change anything. This is fine with me. At 60, I can open the throttle, boost climbs quickly and I am gone. That is the best acceleration I can achieve (O. D. and converter locked). What speeds are you trying to down shift at?



Ronco

 

[Rosshatfield]

Ronco,

Usually at or above 60. My boost climbs but my accelleration doesn't. I think I just need to take that final step and intall the plate.

 

[biggy238]

If you are trying to kick down from that speed, there is nothing wtong with your transmission, you just aren't getting anything done and you are going to prematurely wear something miles and miles down the road. These trucks have a governor as these guys have pointed out and if you are cranking more than 2100 rpm (some trucks vary), the gov will start to defuel your truck. That makes kicking down from overdrive useless because it goes to third and puts your engine at the top of its rpm range where it isn't getting fuel.



The top of 3rd gear on my truck with 35's is right about 65mph and pushing 2300rpm roughly. No gov. spring. If you need your truck to pull on a hill from that speedand it won't do it without kicking down, you might want to consider these:

1) a 3kgsk which is a governor spring kit, it will allow fueling up to 3000rpm (75=80mph in third might be possible)



2) buy a good set of gauges to monitor with and slide your stock fuel plate forward to give you the power you want on hills (the option I went with and am very pleased)



Hope this sheds some light.

Kyle

 

[biggy238]

missed the thing about the gauges.



Fill out your sig with how you're set up right now.



Resist the plate... You'll go from can't kick down straight into I throttle it and the torque kicks loose.

 

[SDrake]

biggy238 you threw me a ringer. I have been sitting on the sidelines with my 94 4x4 auto trying to understand fuelplates, GSK's etc before taking the plunge to up my power. I was just about to order a #6 fuel plate from TST as I stopped by this site for a quick update. I now have a tripple clutch torque converter as a result of a rebuild at 235k miles.



Are you referring to the torque converter slip from a weak torque converter when you used the term "torque kicks loose" or you referring to some other behavior? BTW I am still trying to understaned why TST recommends against a GSK for the #6 plate. Different thread but they are so interrelated I thought I might ask.



Thanks

 

[biggy238]

Sorry, I missed a day here.



Sdrake Yes and no. I was being intentionally vague because in my case i'm not sure if it is actuallly the torque load i'm creating or the PCM causeing my torque converter to unlock, but yes, I did mean that it was unlocking, and it is directly related to my right foot.



I'm going to install a lockup switch (mystery switch) when I get around to flashing my pcm (long story and only pertains to 96 model year) and hope that the switch fixes my problem until I get a built transmission.



I think I saw another post by yourself so i'll read it before I go on.

 

[HFreeman]

Had the same problem with my '95 dually. After messing around with various "fixes " I got a can of PB spray penetrating oil at NAPA and sprayed (read soaked ) my TPS. This stuff will get into anywhere and no disassembly needed. Works perfectly ever since. BTW, the PB is around $4. 00 per can.