Ok i'm almost positive this problem is electrical related, what happens is i'll be out driving & then sometimes the tranny is delayed lockup or slow lockup & sometimes it wont go into lockup & once in a while it will jump out of lockup when it's acting wierd, but then 50% of the time it will run awesome & stay that way for a while kinda like it's in the right mode, but what I was wondering is, should I try the happi box? anyone have this problem at all? i have done the apps reset & same thing, the tranny runs awesome when it's working the way it should TC locks right up ect. then it will just be like someone hit a switch & sometimes it's really bad then get's better, when it get's bad it's a bare to drive because i know it;s not good for the tranny just wondering what all your thoughts were on this, electrical problem? Valve Body Problem? also I heard of something about a govener pressure switch that goes bad what are the symptoms of this? I also heard a bad lockup solinoid can cause problems similar to this also, i'd love to hear your thoughts on this. one thing to is sometimes my battery gauge will only show my batt's chargig to 14 & thne if it's colder out they will show a charge of 14.5. I have never seen this before, I am going to get the codes checked this weekend.

& also the other thing is does your truck shift out of second faster than the rest of the gears I can only get 30@ wot & it seems i would be way better if it shifted later like the rest of the gears, other than that it's great!

DRecu!

 

Hey Drceu, I have a 99 truck also. my tranny would kinda hang up in 3rd and seem like it was slipping especially when it was cold. I have the happi box and and let me tell you, it works. My TC locks up at the same rpm thru out the shifts except 3rd to 4th. I will hang there another 350 - 400 rpms like it's suppose to. I installed it in May. Now I have had a problem with the tranny in the last two weeks. The speed sensor went up causing the tranny not to shift out of first gear. Replaced that, about 4 days later, it kept jumping in/out of overdrive. On this website, i was told to do a APPS reset and after that, three days and 400mi, it seems to have fixed it.
good luck,
Jim