Engine/Transmission (1994 - 1998) transmission shift problems

[GMac]

i have a 98 12 valve with 47re transmission and it will not shift right. I changed the tps sensor and vss and it still does it. It doesn't do it as often but it still does it. It is constantly searching for a gear. It will go from od to drive and sometimes down to second. I need help please. thanks

 

[illflem]

Some folks have cured this by removing the tps wires from their loom and separating them. Seems that stray current around the wires can affect the voltage the pcm sees from the tps.

 

[JerryB]

Sometimes a transmission temp. sensor going bad can cause odd shifting problems, as well. The transmission is not supposed to shift into overdrive, nor lock up the torque converter until a certain operating temperature is reached.



JB

 

[GMac]

where is the transmission temp sensor located? I have a autometer temp gauge and the temp usually runs about 150 degrees. Also it doesn't do it when it is cold, only when it warms up to operating temperature.

thanks,

Gabe

 

[illflem]

On your '98 the sensor is inside the transmission. You can eliminate the sensor as being the source of the problem by unplugging it's connector and jumping across the wires going towards the engine with a 700 ohm resistor. This will trick the pcm into thinking the trans is at proper operating temp.

PM tdr member shendren, he went though every possible cause of this problem and can give good advice.

 

[GMac]

what color are the wires that i need to jump the resistor to? I am going to try this this afternoon. thanks

 

[illflem]

They are light blue and violet on '94-'96. Could be the same on '98 bit I'm not guaranteeing it.

 

[JoshPeters]

I had this problem with my 96 during the winter, mostly when cold. I talked to a friend that works at a Dodge dealership and he said to Change the Transmission fluid, and filter. I did that and problem... gone! Mine would hunt for third, like you are talking about and sometimes overdrive. He said it was from the fluid pressure being low and the change of path in the valve body. The sudden change of path from full to empty the valve body would loose just enough pressure for it to hunt like that.

Something "cheep" to try.



Josh

 

[grtescpa]

Originally posted by Gabe32

i have a 98 12 valve with 47re transmission and it will not shift right. I changed the tps sensor and vss and it still does it. It doesn't do it as often but it still does it. It is constantly searching for a gear. It will go from od to drive and sometimes down to second. I need help please. thanks

Make sure the throttle linkage is set properly. I think its 5 inches or so. The line pressure has to be correct along with the kickdown setting. If your throttle cable is old its probably out of adjustment. The service book shows two cable adjustments that must be accurate. I don't have my book handy at the moment. You will need a hydraulic pressure Gage and a special tool to set the kick-down. The tool costs $16. 00 from Miller tools. After all that simple stuff checks out and you still have a problem I would let a professional trouble shoot it.

 

[GMac]

these are also good ideas about what could be wrong. My fluid levels are up, and it is less than 5k miles old. I ran amsoil synthetic in the transmission and the transmission has 55k on it. I don't think it is a fluid issue because it shifts exactly how it is supposed to when it is cold, but then when it warms up it doesn't know when to stay in drive or overdrive. I separated my tps wires about a foot back from the connector and that didn't do the trick and I just got back from radio shack to pick up a 700 ohm resistor but all they had were 680ohm resistors. I don't know if it has to be a 700 or would a 680 work? I want to cover all the baby steps before i have to dive into my transmission. thanks

 

[illflem]

680 will work.