Hard time engaging in drive

[TXPSDmatt]

I have a 2000 F-250 PSD with auto trannie, it has a problem engaging into drive. I will put it in drive and the truck does nothing even when pressing the gas, but on occation it will work fine. Usually i have to put in 1st, 2nd, then drive, even at times it still wont engage after taking off in 1st. Reverse and neutral work just fine. The truck has a 2.5" lift, 35's, Bullydog programmer, 4" exhaust, and a K&N intake. I changed the oil in the transmission as well as the transmission filter, hoping to fix the problem and still nothing. The trans oil level is good. Can anyone give some advice or help, I would greatly appreciate it. Thanks.

[Justin.Hutch]

So does it go into drive everytime when you put it into 1st? Or only sometimes also?

Also if you put it in drive (D) and it doesn't engage, will giving it a little throttle help in engage or feel like its trying to engage?

[TXPSDmatt]

Only sometimes does it go into drive when i put it in 1st. Sometime giving it throttle does help and when it does move it shakes. Just Earlier this morning it took off in 1st then I shifted to second then put in drive, after putting it in drive the truck reved up while rolling forward and went no were almost causing an accident, then it eventualy engaged and i was able to accelerate and move out the way.

[TXPSDmatt]

Putting it in drive and then giving it throttle, sometime helps and sometime it will roll forward like its trying to engage.

[SixStringMadness]

do you have any idea what your line pressures are?

[TXPSDmatt]

I havent checked pressure on any lines yet. Also which line are you asking about?

[SixStringMadness]

Originally Posted by TXPSDmatt

I havent checked pressure on any lines yet. Also which line are you asking about?

internal line pressures. Could be an issue with the pump.

[Justin.Hutch]

Originally Posted by SixStringMadness

internal line pressures. Could be an issue with the pump.

I was gonna suggest the same thing

[TXPSDmatt]

Well i put in an oil treatment from lucus and it helped for a bit but i still have the same problems from time to time

[TXPSDmatt]

I've done some research and some work to the truck since last post, i finally got it to a science, once the transmission is in park while running it doesnt go into drive. Even putting it in 1st doesent work either. Im thinking its getting hot or the oil is breaking down very easily. Im going to flush the oil out and put a new filter and put in a trans temp guage. If all else fails i will pull out the valvebody and flush it out/clean it. I've been told that it could be debris stuck in one of the valleys or in a spring. Any other info would be great.