Why can't I get transmission to shift up out of low on it's own, or manually??
1991 GMC 2wd 1500 5.7 4l60e transmission: trans. won't shift up out of 1st to 2nd or any
other gear on it's own or even when i manually try to shift to 2nd or any other gear. It
freewheels exactly like it's got a stall converter. It pulls normally until i try to shift up?
Vacuum problem or possible solenoid (s)??? Thank you for anything you can help me
with!!!