I have a 97 Chevy G2500 with 4.3 v6 automatic and when I put it in drive it will shift fine until it tries to go passed 3rd gear. After 3rd gear it just seems like it goes into neutral. It seems like it goes into 4th for a second but then it just revs up and never goes into 4th. It doesn't seem to slip in any of the other gears. If you have any help to offer please let me know your tips. Thank you.

 

what tranny do you have 4L60 or 4L80?

gm stated on 4L60/4L80 there is a replacement harness for the VCM because of a bad ground condition developing

also starting 1998 GM revised the shift solenoids, so if you got a 4L80 it's a possibility you would have to change solenoids 1-2 and 2-3

 

I have the 4l60e in my van

 

check out the transmission fluid. has it turned brown ? if yes then get it changed. also check the transmission mount.

 

do the easy checks first, but deffo take a look at the VCM harness, if you can use white lithium grease on the connectors if you need to replace it

 

My 1994 Silverado 5.7 would not shift into overdrive. New spark plug wires solved the problem.