Should i buy a new transmission

[Mxminiracer99]

So I have a 99 ranger single cab long bed with a 4.0l 4x4 and a 5r55e. The transmission has almost 200k, I saved it from being junk and previous owner never changed the trans fluid, so I did that at 160k when I got it and it was black, the only problem I am having is that at 50mph when you punch the throttle it wont up shift till you got off the throttle, other than that its been fine. Should I just get a new trans with a shift kit for $2400 or buy an upgraded valve body with shift kit for $300 and try that, nobody around me rebuilds transmission and is dont have the time to rebuild mine, I have no trans codes either

 

[superj]

Maybe the kickdown is out of adjustment?

 

[pjtoledo]

are you saying that at 50 mph you floor it, the transmission downshifts and the truck gains speed, but the transmission won't shift back to the higher gear until you back off the gas pedal?
how fast does it go in that gear, what are the RPMs?

sounds like how my 2000 has always run, but it's a 3.0 and struggles above 75-80.

 

[DILLARD000]

Your describing slipping that is typical with high mileage 5r55e Transmissions.
Insure ATF Level is good with Tranny warmed up, engine idling, in Park on level ground.
I'd try the following in order listed to extend life of this tranny as much as possible::
* HandPump ~24oz of ATF from DipTube, replace with 24oz LucasTransmissionFix; this is basicly HiViscoity ATF that can help shifting.
* If no improvement, HandPump 1qt ATF from DipTube, replace with MerconV AmsOil#SSMV or RedLine#D4; drive 50+ miles; repeat several times.
* If no improvement, drop TrannyPan + ReTorq VB Bolts + NewFilter + NewPanGasket + BandAdjust.
* If no improvement, new\rebuilt ValveBody with New BondedGasket+Solenoids+ShiftKit+ReverseKit; CentralValveBody\Donny in OK is a source.
If none of those help, prepare for a complete rebuild or new Tranny.

 

[rusty ol ranger]

Your describing slipping that is typical with high mileage 5r55e Transmissions.
Insure ATF Level is good with Tranny warmed up, engine idling, in Park on level ground.
I'd try the following in order listed to extend life of this tranny as much as possible::
* HandPump ~24oz of ATF from DipTube, replace with 24oz LucasTransmissionFix; this is basicly HiViscoity ATF that can help shifting.
* If no improvement, HandPump 1qt ATF from DipTube, replace with MerconV AmsOil#SSMV or RedLine#D4; drive 50+ miles; repeat several times.
* If no improvement, drop TrannyPan + ReTorq VB Bolts + NewFilter + NewPanGasket + BandAdjust.
* If no improvement, new\rebuilt ValveBody with New BondedGasket+Solenoids+ShiftKit+ReverseKit; CentralValveBody\Donny in OK is a source.
If none of those help, prepare for a complete rebuild or new Tranny.

Slipping would result in no or little gain in speed though.

Are you *sure* it wont upshift? Or do you do like i do and lay off when it sounds like its going to come apart?

If you have a tach most auto trans wont upshift untill redline or close to it under those conditions

 

[DILLARD000]

He's describing slipping while trying to shift, not a constant slip at steady speed in a specific gear.