I have a 1998 chevy ck1500 with a 4.3l vortek and 4l60e trans. Driving to work one morning the trans acted like it popped into neutral, when I got below 50mph it went into third and stayed there. I could manually get second and reverse but no first or fourth. Also the check engine light went on. If I shut the truck off then restart it drives normal for a few hundred miles then it happens again. I checked the code and it came up "shift solenoid B electrical circuit". I replaced both A and B solenoids and it still does it every couple of hundred miles. took it to a trans shop and they think it might be the computer but not sure.

 

try to reset the computer..take the pos. off the battery and wait 30 mins or so.. and it'll reset it..see if it does it again

 

I've done that. Still does it every 200 miles or so.

 

Thread search the Silverado section. Apparently the 4l60e has a couple of common problems.

 

These are in the Valve Body, Right? did you do it yourself (the change ) or a shop. If a shop how much did it cost you? I'm having issues with mine but my Service manual says possible clog (I don't have any codes however). Just need a heads up on how hard it would be to take out the VB.....