alright sooooo 93 s10 blazer 4.3 cpi vortec, approx 40000 miles after a rebuild, standard 4L60E/700R4 transmission, 4x4 with transfer case.
i installed a transcooler ran all new lines did a fluid change, fliter gasket cleaned the pan the usual, seemed fine drove it a bit, started to shift hard 1-2 when cold, softened up when warm didnt worry to much let fiance drive it no reports of anything. i drive it one night shifting reallllly hard 1-2 and a lil hard 2-3, so i parked it, checked transfer case to see if the seal had failed and was sucking fluid into the vacuum tubes i could not feel ANY fluid, checked trans fluid level right on the cold line, so my question is can a dry transfer case cause hard shifting, and if thats not the problem wth is

 

will be checking throttle position sensor

 

nah transfer case really shouldnt have anything to do with the way your transmission shifts. its a whole separate unit. i was always told my whole life if you have a older vehicle to never change the trans fluid due to that gritty old trans fluid is what actually keeps some older transmissions working. maybe add some transmission additive to it.

also check the lines going to the cooler, make sure none of them are kinked or if you installed a used trans cooler that nothing is clogged

 

If it is the original trans. The fluid change could have freed some particles that drained into your valve body and is causing ur shift solenoids to stick.

Transfer case wont affect shift quality.

 

So change solenoids?

 

I would start by adding a bottle of Lubegard (red or platinum). Its OEM approved trans additive and is designed to free shift valves and improve trans fluid.

 

There are some good post about this. Problems and the fix. One called things I have learned I think. Do a search until you find the post. I had a problem also and it helped me. However I think if I remember right your problem is the solenoids but not positive. Do the search and save some time and money. I think swartikk wrote the thread and it's under helpful threads at the top of the page. Good luck.

 

Look in this section-- Engine and Transmission. Sticky: Helpful threads. Submit threads here!! There is a lot of good info on the 4L60E trans.

 

how do i check the kickdown, i believe its electronic i dont see any odd cables attached to the throttle

 

if its a 4l60e (look on passenger side at the trans,the big plug,if its round its a 4l60e,if its square its 700r4,big difference)

if its a 4l60e there isnt any cables. kickdown? its all electrical with help from the throttle position sensor on the throttle body. (which i would change before doing anything)

40k on a trans rebuild and this is happening? Strange. either the one who rebuilt it half assed it, or you just got a lemon.

id say its a valve body issue/shift solenoid issue. If you dont know enough to get into the valve body etc id suggest to take it to a good shop..

change the tps on the throttle body,and if no change. take it to a reputable shop. NOT a trans shop. they will just suck you into a trans rebuild.