When I'm going down the highway (speed limit=40) and I'm not really gettin on it, just puttin along, it will shift into OD like 35-40. But when I really get on it like taking off from a stop sign I'll get up to 55, won't go into OD, it shows its at about 1800-2000 rpm and then i'll be cruising at 55 and like 2 minutes later it will finally go into overdrive. It seems like when I'm puttin along it goes into OD real quick but when gettin on it, it takes some time to finally go into OD. I'll speed up to like 60-65 so its about 2000 rpm, ill let off gas to go back down to 55 and still won't go into Overdrive. Do I have a problem or am I just worrying too much?

 

Yes worrying way to much.....Trannys react to different speeds, elevations,weights etc in different ways. As long as it's not slipping your prolly just fine.
You can have a filter and fluid change if you just feel somethings wrong or if it act like it's hesitating going into gear.

 

alright, I just bought the truck pry like 2 months ago, but my brother has a 99 250 Lightduty, and hes on like his 3rd tranny and 2nd motor, so I'm worried I'll go through the same thing

 

Well that's not normal about your brothers truck. Most of these trucks can go 400,000 miles on stock engines if not more.

 

Yea it was my sisters fault. Somehow the airfilter disappeared? ha I have no clue how, but she took his truck and went and beat the hell outta it in mud and sand and got it stuck and ****ed up the 4wd and she sucked up a bunch of sand into the motor. and he bought the truck with 70xxx miles, 6months later the tranny went. Got a new one installed at Ford dealer, lasted like a year and then he only had first gear. took it in and they said it was a sticky valve. It never shifted right after that, then last year it went out, so he had it rebuilt with a shift kit, now a year later reverse is gone. you give it gas, it free revs then it will struggle but will reverse slowly. the guy is blaming it on him runnin 35" tires