so this seems strange
my trans 4 spd auto, shifts pretty badly, and late. sometimes it seems to want to stick in a gear.
let off the gas and it shifts, in an old truck it would be the vacuum modulator, I doubt a 99 has one??
for instance at mild acceleration (around town) it will be at 3000-3500 rpm before it will shift at 30 mph

when I installed the hypertech programer III 87octane program, it got so bad it would hit the rev limiter in third gear and still not shift. and if I let off the gas it would just act like the truck hit a wall, then it would shift after it slowed down a lot, then when I stepped on the gas it would accell a bit, then slip back into 3rd and rev all the way up again.

GRRRR
why the #$%% do trucks need computers anyways, it was so much easier to work on things that only had mechanical parts!

help help help [sm=pcwhack.gif]

 

did you pull codes off the truck? the hypertec will do it for you too, but soulds like the tranny is going

 

oh mother ... i pray your tranny is ok... i just got a new one and a bleeding rectum from the bill!

now you mention it... my tranny never acted this way untill i installed the hypertech...

aaaahhhh crap now im paranoid

 

Well I don’t see what the hypertec could have done I mean the tranny isn’t comp controlled. I have a superchip and it will adjust shift points on some vehicles but mine isn’t one of them because the tranny doesn’t work off the comp

 

yeah, i know the shift points are cable adjusted.
i am thinking maybe it is only seriously loosing it with the Hypertech because of the extra power.
I am almost certain the tranny is shot, but just do not understand why?
and it is not throwing a single code at all!!!!!!!!!

 

well that is a little odd if its not throwing a code but the little extra power could be making it a little more noticeable take out the hypertec and see what it duz then take it to a good tranny shop and see what they say

 

yeah i did take out the hypertech, and it is better, but still feels messed up.

 

well if its better with the hypertec then i would say the extra power is making it more noticeable, id take it to a tranny shop and see what they say

 

I can't see a programmer causing the trans problems. When my trans puked it didn't set a code at all. what year is your truck? Chrysler has some software updates for delayed up shift for the newer trucks and also addresses some durability issues. By the sound of what your descibing I'd say that your about to joint the rebuild club.

 

the hypertech programmer just made my truck ping pretty bad under load or going up hills.. that CANT be healthy for the engine but im running 93 octane now and get a low temp stat monday so maybe that will help out