Hey guys, lately when my car is cold(in the AM) and i try to put it in drive it doesnt shift or takes about 10-20 seconds to shift or if i go down to 1st it will ingauge and i can then put it in drive and go

After it warms up it works fine. What could cause this? Fluid level is good and doesnt smell burnt or anything. Is it something as simple as a filter or am I in trouble?

this is a 700R4 in an 84 S-10 4x4 Blazer I have only had this vehicle for about 2 months

Any Ideas?