Hey guys I really need some help on my 2002 Ranger auto transmission. These problems have been happening for about a year now and I can't figure them out. Every time I start my truck and put it in gear it is extremely delayed until finally engaging. This goes for reverse and drive. It started out with 1st and 2nd gear but now it is increasing. Once I am on the road, my transmission constantly slips out of gear for a good amount of time. I can even be in 3rd or 4th gear going around 40 MPH and it will slip, then engage. Slip, then engage for about 10 minutes. Every time i stop at a light,stop sign, or hill it goes back in to neutral and I am just stuck there until it kicks back in. The disengagement also happens a lot when I slow down and take turns. I replace my transmission fluid normally. I have been worried about this for a while now so any advice or ideas about what could be happening would be greatly appreciated! Thanks in advance!

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2002 Ford Ranger EDGE Supercab