I just picked up a 86 Trans am lb9 700r4

I sucked out almost 4 quarts or Trans fluid through the dipstick tube and put freash fluid in it because old fluid was nasty.

When its cold it takes over a second to pop into drive or reverse.it shifts fine just seems like it takes to long to pop into gear.is this a issue or normal? I haven't had one of these cars in. Almost 10 years

Also on acceleration there is a slight whine from either the Trans or rear end and the rear end is wet . So I'm gonna try to fill it. Is the plug on the. Cover or the rear end itself? I see what looks like a rubber plug on the cover but I don't wanna brake it

 

First how bad was the fluid you sucked out? Maybe you nead to changes the filter inside the trans.
And on the diff yes the small rubber cap on the cover is where you fill the diff at.. Fist see if its full , if the fluid is just at the bottum of the fill plug the its full . For a car of this year I'd just change the fluid in the diff. remove the cover and drain and inspecked everything, then put a new gasket and replace the cove and fill.

 

Fluid was brown and smelled now it is redder and doesn't smell.I'm gonna fill the diff. Tonight