[Davescort97]

Welcome to AF!

When it's in reverse does the engine rev up before it grabs that gear, too? Normal time lag between the shift of the lever and feel of the shift engagement is .9-1.1 seconds on the Aisin Warner 80-40LE transmission. If it takes longer than this with engine rev-up you probably have insufficient line pressure. If it does it in both low and reverse this is the problem. If the problem is line pressure the fluid pump isn't creating enough pressure from the onset. This is the internal pump on the tranny not to be confused with the torque converter. Once the engine runs a little faster, the pump creates enough pressure to engage the low/reverse clutch pack and go. When you changed the fluid did you use type IV fluid, Mobil JWS 3309 or GM specified fluid part #88900925? Any other fluid is not reccomended. Usually when this happens the pump is weak or the filter is clogged. Did you change the filter or just drain the tranny with the plug?