1998 1 ton transmission problem

automatic transmission won't shift to second without lifting off gas pedal
Manual shifting isn't much help...Any ideas???

I would say off the top of my head...It almost sounds like there is no 2nd gear. So it skips 2nd. Can you tell if there is a wide ratio change between the shifts? I could be way off. As there is 2 types of trannies that fit these.

You probably need to check for codes and watch the data stream within the computer system. You need to see if the computer system is telling it to shift like that or if the transmission itself is at fault.

got the solution

remove the transpan and on the back side of the trans there is an electronic sylnoid valve (there should be 2 right next to eachother) the one on the d.s. is 1-2 shift syl., the one on the p.s. is 2-4 shift.

some of the newer transes have a screen on the ends of these sylnoids that may get clogged. nevertheless, your best bet is to replace these, yes both of them, because you cant go wrong with the new part. list price at the dealer is about 20.00 a piece. (trust me, i have a shop, you want to get them at the dealer.)

if this does not fix the problem, there is a hydrolic syl on the pass side of the trans. this may be stuck or have a seal problem. just take the retaining clip out and it will just fall apart. this is the syl for the 2nd shift band and is the only part of the trans that is engaged during second gear. just replace the seal with the new one, using grease to install and replace the clip. if there is luid in the trans at this time, just jack up the pass side of the van as high as you can for minimal fluid loss.

ALL OF THESE PARTS ARE SPRING LOADED SO BE VERY CAREFUL THAT YOU DON'T LET THEM FLY APART. BE EASY AND TAKE YOUR TIME. AND...ON THE NEW PAN GASKET MAKE SURE THERE IS A GROOVE OR DIMPLE CUT IN ON THE PASS SIDE (you'll see a hole, bout an 1/8 in. that cannot be covered, this is second gear luid pass).

I own a 1999 Chevrolet express van now its 116000 miles but when was about 80 miles its started to abruptly shif up from 1st to 2nd gear, it happens when after a long ride over 50mph or a fast acceleration (full) when go back to lower speed when accelerates its shift abruptly to the next gear either 1st to 2nd or 2nd to 3rd and at the begining of the problem the "service engine soon" lamp went on and from them numerous times i made checked with the dealer an at diferent shops but the problem persist because here in mexico they are not trained according to gm or they don't have enough support

What is the code?

I just return from a several repair all the disc inside the transmission were changed and some bands and the turbine but after all because was a rebuilt turbine its started to sliping shifting from 1st to 2nd at lower revolutions the codes that shows are 161 and 1870

Someone help us its our vacations van

I took to the shop again the problem wasn't fixed at all, although it works fine its start to slipping after a short trip in the highway, with speed over 50mph, when arrive to a reduce speed area like stop sign its start again shifting abruptly from 1st to 2nd and 2nd to 3rd and when i speed up faster (i usually speed up very slowly trying to protect te gearbox) but when i speed up faster the abrupt shift seems to be softer and i think the computer show the same codes again, any help so far? thanks

I took to the shop again the problem wasn't fixed at all, although it works fine its start to slipping after a short trip in the highway, with speed over 50mph, when arrive to a reduce speed area like stop sign its start again shifting abruptly from 1st to 2nd and 2nd to 3rd and when i speed up faster (i usually speed up very slowly trying to protect te gearbox) but when i speed up faster the abrupt shift seems to be softer and i think the computer show the same codes again, any help so far? thanks
Take it back why are you attempting to get an impossible diagnosis in this environment, it has something wrong internally or the electronic controls are are a problem.