Engine/Transmission (1994 - 1998) Wierd Shifting Cold Auto

[EDudley]

Hiya folks, first post on here. Before anythign else... GREAT SITE!!!!! ok, so the problem is with my '97 2500, 4x4, auto, with 142xxx on her. bought the truck last feb, roughly 123xxx. No problems with truck other than some front end work. I live in Ct, currently in school in Maine. Heres the routine, rigth now truck is not plugged in, not all that cold, and I usually have to drive about noontime, so the truck is about as warm as it will get just sitting. I allways let it warm up for about 10-15 min in parking lot while i go back inside. When i leave, i usually trun the overdrive off, i am going up and down littel hills and not going very fast ,and i try to warm it up a little. When it sees a hill, or has a decent load on the motor, the transmission seems to jump in and out of... lock-up i am guessing, the overdrive is off, otherwise i would say that it feels liek it is in and out of overdrive, i turn it off for this reason. Sometimes it's liek it can't make up its mind, it just goes back and forth, in and outta gear?? lockup?? once warmed up, it dosent really do it, goign faster with overdrive on seems to help. . 50-60mph it stays in overdrive and does not shift. Im hoping that it is nothing really major, auto transmisions just scare me though!!! Sorry fro the long post but wanted to giv eeveryone out there a good picture of whats goin on, thanks alot..... and did i say GREAT SITE!!!!

 

[bmoeller]

What speed does it hunt back and forth? Do you have 3. 55 gears or 4. 10s in the diffs?



Mine will do the same thing, but at any temp, when driving behind another vehicle and can't speed up any. I've only had that happen twice or so.



The torque convertor clutch is going in and out of lock-up. Mine does it around 30 mph (I have 4. 10s).

 

[BernieFreeman]

Do a search on tps my truck would do the same thing replaced it and the trans works like new for 195K, I would do the test on it. There are explanations on proper setting and such in the forums.

 

[EDudley]

thanks for the info guys, i have 4:10's and its seems do do it the most between 30 and 40, like you said. But sometimes even over 40, when the truck is around 2000 rpm's, so its not that it is being bogged down enough to want to shift. Could it be just cold fluid and torque converter. I know that my '88 half ton gasser did strange things within the transmission in cold wether, and that has over 230xxx on original transmission... . but these are a differnt beast. Plus the thruck has never sat as much as it does now. I only drive it at least every other day. Thanks again. ps. . no bombs done to truck either, soem towing, soem heavy, some not. Thanks

 

[JoeMartin]

TPS TPS TPS.



Just went thru that with my 94 was all over the place when shifting cold or hot, jumping in and out of lock-up. I pulled the TPS out drilled 2 holes cleaned it out and hogged the holes out so I could adj the voltage, even tho I could only get . 998V-1. oV out of it the problem is fixed and its like new, Now alls i have to due is adj the TV cable for my shift points.

Where abouts in CT are you and are you going to be home during the X-mas Holiday?

I'm about 30 mins from Hartford CT right out side Springfield MA. If you want a hand with it e mail me I'd be glad to help you out.



Joe.

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