P0781 - 4r100 - delayed or no 2nd gear

[Drae]

I've been having this problem with my wife's 04 Navigator for a while and been digging around for answers but I've had no luck. I was thinking maybe you 4R100 guys can help me out with solutions if you've had this problem before. The fluid is clean and full first of all and I have 143,000 miles on it.The shift is late between !st and 2nd gear and will shift in between 3500 to 4000 rpms when it was usually around 2000 depending if you're creeping or if you're on it hard then it was around 4000 rpm. If I let it shift on its own in Drive it will start shifting hard into all gears after a while. I've got the blinking OD light only once and when I took it back home and turned it off and back on I haven't seen it do it since and that was over 3 months ago. I baby it now of course and shift it manually into 2nd (D-2-D)at the proper rpm according to how I'm driving it and it shifts in every gear smooth as water all day. It doesn't slip unless I'm on the highway and floor it to pass someone which it usually downshifts to 2nd gear. It seems to be something with second gear because it downshifts to first gear fine if I floor it. I was thinking just change the solenoid block as someone advised me to do, but I wasn't aware of the slip at first and that's what scares me into thinking its more than just solenoids. I also get the P0781 code every once in a while and clear it with my Xcal 2 programmer/scanner. I'm open to any suggestions. Sorry for the long post just wanted to give as much info as possible.

Thanks in advance.

 

[DR3W]

Idk if were having the same problem but mine just started this. It wont go into 3rd. Around 35-50mph, expecting it to shift around 2000-3000 rpm. It just keeps reving but wont shift until about5-10 seconds than shifts violently. Only today has it started, idk either!






2000 xlt 4x2 4.6L 170k miles

 

[DR3W]

So you manualy shift from D-2-D???

 

[Marsr]

2nd Gear

2nd gear is the only gear with a band on it, I was told by the tranny guy that is rebuilding my tranny, it sounds like you may need a rebuild soon.

 

[Drae]

Yeah I am going to rebuild it because it's too expensive to just throw parts at it and get no results. I have someone who is going to rebuild me a heavy duty trans for $2200 with better parts. And yeah I am shifting it D-2-D because it downshifts just fine when I'm stopping. I was doing 1-2-D but when I downshifted manually into first at any speed above 5 it makes a nasty clunk sound that wasn't there before when doing it before this problem occured. It also begins to shift hard, but this way it shifts smooth with no problem. I also only use OD on the highway so I won't have the TC working too hard locking and unlocking on the streets and to avoid as much shifting of the transmission as possible. Because that's when then hard shifting begins then I have to pull in somewhere and turn the truck off for about 5-10 seconds and its fine again. Its been 5 months or so with this problem and nothing has gotten worse so I will continue my method until its replaced ASAP! Thanks for the input fellas.

 

[WCAWI]

Its probably a simple problem that we've run into before. It sounds like the line regulator valve for the 2nd accumulator is sticking. We put in the Transgo E4-VL-LR3 steel valve to fix it. The accumulator valve body is the very front body and is easy to remove. Just take down the pan and filter and unbolt it. Instructions come with the valve kit. You might as well replace all the line reg valves while you in there. Three come in the kit and they are all the same. The same problem will occur with the other gears if their valves stick. If 3rd is late, many times reverse will be delayed too.

 

[tmajikman]

Its probably a simple problem that we've run into before. It sounds like the line regulator valve for the 2nd accumulator is sticking. We put in the Transgo E4-VL-LR3 steel valve to fix it. The accumulator valve body is the very front body and is easy to remove. Just take down the pan and filter and unbolt it. Instructions come with the valve kit. You might as well replace all the line reg valves while you in there. Three come in the kit and they are all the same. The same problem will occur with the other gears if their valves stick. If 3rd is late, many times reverse will be delayed too.

Marked in favorites for the future, just in case, thanks for the info.