Hello , I don't know if this will work or not but here goes.
I've got a 97 chevy p/u 2wd 4.3l v6 with 208k on it best eng I've ever had. However, the trannny a 4l60e, on the other hand is giving me problems. It doesn't want to stay in overdrive (o/d) at all. I just changed the fluid and filter recently and now the thing won't even go into o/d at highway speeds, seems to do fine around town once it gets warmed up. I took it to a shop guy and he said could be the solenoids acting up not wanting to shift when they need to. I 've had to rebuild this thing once at about 116k which is normal for chevy electronic controlled tranny's. Is it normal to have these thing to be rebuilt about every 100k or so, and can anyone give me any help as to what else to try to diagnose? The fluid is full and thecoolant is full and no leaks that I can see.
shadtree mx