Ford Repair: 93 Ford Ranger Transmission, vacuum modulator, shift into overdrive

Question
I have a 93 Ford Ranger w/4.0 V6 engine & automatic transmission.  It has 160,000 miles on it and just recently it won't shift into overdrive when on the highway and in the morning when I first start driving, it takes a while to shift from the first to the second gear.  Could give me some possible causes and also a ballpark as to what I should expect to be hit for as far as cost.  Thanks Erik.

Answer
Hello and thanks for the question...I'll try to help.
I would check the fluid level, and also the vacuum modulator (on the transmission passenger side, rear), look at the vacuum line--if it has ATF coming out of it, replace it. As far as the cost of a rebuild goes....it really varies depending on cost of parts. Typical is about 1200.00-1500.00
Erik