94 lumina apv tranny problems

hi i was wandering since it has gotton colder my tranny wont engage right away , after it warms up its fine but if it sits overnight when its cold out u have to let it warm up about 5 min before it will go anywhere but after that it shifts fine anybody know what might be wrong thanks much

Old seals get hard in cold weather, and don't conform to sealing surfaces 'till fluid warms them up a bit. An additive that contains a seal conditioner may postpone the inevitable for a while. I've had cars that did that for years before going bad completly. Had a Caprice that wouldn't go into reverse at all during winter months.