I have a 2000 Z28 (4L60E) and having major problems with the vehicle shifting from out of 2nd and into OD as well. Car shifts GREAT from 1-2 without problems and into reverse and all as well. I just don't know if the tranny is truly gone or I need to replace a servo or possibly something else. Any help would would be greatly appreciated before I sink money into a tranny I might not need! Thanks in advance.

 

I am not sure I understand you say your having problem with it shifting out of second and into overdrive as well, Then you say it shifts find to second?
describe exactly what happens when you take off 1-2-3-4