I have a 2000 taurus ,transmission won't lock up in 3rd or 4th gears. sorry,automatic.it was slipping,apperantly,bad enough to over heat the motor before they finally pulled over. anyway,the 1st thing i would like to know is,how do i identify which trans it is?2nd,can i drop just the trans or does the whole ***. haveto come out? and lastly,what other vehicles run this trans?

2wd right?(1995 is GEN1, T100)
auto trans or manual trans no told and both are told.
we can't guess drivelines blind,so tell it.?
2.7L, 3.0L and 3.4L engine options new.
toss coin land on A/T box. (most common )
the TCM decides all this not you,
the Tcm/Pcm/or TCU are all transmission brains , the PCM does engine too, and tells the TCM speed, and engine loads (hills etc)
rpm based on all that and gear ratio, in the transmission, 1:1 or overdrive. too and the axle ratio and tire size (circumference)
are tires stock, or low rider tiny.???????
5 speed manual or 4speed automatic and 4 engine choices not one told and if an automatic the TCM is turned to all things stated above.
a hard fact that. the RPM drips in OD ,overdrive and TCC lockup
the service manual lists 5 transmissions
A340F, A340H, A440, A442F and A343F units
top 2 are A340e & A340f (USA answers me) 2wd/4wd

A340F (30-40LE) 4speeds + tcc

seen too on
2000-2004 Tundra (4x2)
A = Aisin-Warner Automatic.
340 generation 3. 3L v6 used.
E=electronic shifted (TCM brain
F= 4wd same as E shifted.
3 electrically controlled solenoids for shifting and torque converter(TC) lock up(TCU runs the SHOW)

There is s TV cable here too, that causes upshifts late or early.
super hard top find this, Asian boxes. but here goes.
?1st: 2.80
?2nd: 1.53
?3rd: 1.00 (end to end lockup , look ma' NO gears here !)
?4th: 0.75 (23-spline, 0.705 21-spline
4th gear cam be less on smallest engine.(less rpm drop)
now you learn vast version of transmissions exits.
I read the side of box and it tells me the model there fully, every time.


so are you not getting 4th gear OD or the TC lockup failing
scan the PCM see if there are P07xx errors"? tranny errors. ?

in 3rd gear the RPM is the axle ratio and tire diameter (pi X r squared is circum and distance moved is that)

I can tell you the math below see the online calc. at end here.
and some TC slip. (it slips not locked up)
4 gear is RPM ,= is 0.75 x 3rd gear RPM. and tc slip.
TCC lock up is is less RPM but that depend slip and hills.
that is why I call them slush pumps, TC SLIPS and turns HP in to wasted heat and is why TCC was mandated by the EPA, for more MPG, and less waste.
that is how the pump slips as they say.

why not just see if all gears work (count them with easy right foot on flat earth)
and TCC locks up, in 4th
and scan the PCm for errors.
1,2,3,4+TCC is really like 5th speed, if you noodle that.
4-1/2" gear,(5th) locked.
make sure TV cable not rusted and jammed up and for SURE not jammed in the Pulled out position, rusted, there. and is WOT
wot is wide open throttle and that make the tranny shift way late
or never goes past 3 gear... test it.(or worse 2nd)
I see folks put a new transmission $2500 for the want of $20 cable.
wow. that. The TV cable bad is an on car fix.
P0750 to P0770 are all tcc errors to the box. scan it if gears ever shift wrong. and speed sensors failing or clutch packs slipping in the box,will dtc code out too.

so in 3rd gear the axle 3.4L auto T100 4x4 should have 4.30 gears.
so 1:1 x 4.3 is still 4.3 so 3000 rpm the read prop shaft.spins

at 3000 rpm and axles spin 698 RPM( AND TAD LESS TC SLIPS.)
knowing tire circumstance or diameter. nets speed.
manual trans runs 4.10 axles. (and no slip at all)
if not running stock tires the SPEEDO lies to you.
taller large tires spin slower and VSS lies. to cluster.
called ticket getter
235/75R15 (stock'ish)
Diameter : 28.9"

here is 4.3 axles.
3rd gear, 60mph , axle above 28.9" stock tires
is 3000 RPM
so shift to 4th, be on flat ground and light right foot and not hills]
and TV cable not JAMMED (rusted and locked out)
https://purperformance.com/p-29669-rpm-calculator.html

so 4th OD is, what .75 x 3000 is 2250 RPM (my guess never seen)
TCC locked up ,is less RPM, a bit.

so learn to scan any TCM(PCM) when gears fails.
scan it. now.

If caught soon enough it may indicate only a relative inexpensive service but that is just a guess. I would not delay getting it checked it will cost you dearly if you do.

I hate to tell you but it sounds like your transmission was rebuilt incorrectly and need to be corrected or tossed and start anew, new transmissions for your truck are roughly $1,600. I'm sorry to hear about your problem.

For Automatic transmission problem,Check the list of help links below.click the link below:----Automatic transmission troubleshooting:----

http://howtobyme.blogspot.com/2011/11/automatic-transmission-will-not-go-into.html

---------
Automatic transmission shift lever issues?-------

http://technoanswers.blogspot.com/2012/01/automatic-transmission-shift-lever-hard.html

-----------
AUTOMATIC TRANSMISSION FLUID LEVEL? --

http://schematicsdiagram.blogspot.com/2011/07/how-to-check-automatic-transmission.html

--------------

AUTOMATIC TRANSMISSION FLUID AND FILTER?

http://schematicsdiagram.blogspot.com/2011/07/how-to-change-automatic-transmission.html

-----------
Transmission fault light on car dash?

http://schematicsdiagram.blogspot.com/2011/12/transmission-fault-light-on-car-dash.html

--------
Transmission shifting problem?

http://schematicsdiagram.blogspot.com/2012/01/transmission-shifting-problem-on-toyota.html

--------
Transmission Slips out of 2nd gear?

http://repairhelpcenter.blogspot.in/2012/02/transmission-slips-out-of-2nd-gear.html

-----------
OD light flashing and transmission fluid leaking?

http://repairhelpcenter.blogspot.in/2012/02/od-light-flashing-and-transmission.html

----------
Why Transmission fluid leaks near radiator?

http://repairhelpcenter.blogspot.in/2012/02/transmission-fluid-leaks-near-radiator.html

----------
transmission fluid leaking?

http://technoanswers.blogspot.in/2012/02/ford-windstar-transmission-fluid.html

-------------
****** wont go in reverse?

http://technoanswers.blogspot.in/2012/02/dodge-neon-wont-go-in-reverse.html

-------------
Automatic transmission will not go into reverse?

http://technoanswers.blogspot.in/2012/02/dodge-automatic-transmission-will-not.html

----------
Transmission is making buzzing noise?

http://technoanswers.blogspot.in/2012/02/transmission-is-making-buzzing-noise.html

-----------

This will help.

Thanks.

could be a solenoid
low oil
worn overdrive friction discs

you can source a used transmission from a wrecker
and drop that in

from the pictures i cant tell if its overdrive is under an external plate at the end of the gearbox
and repaired with an overdrive kit

P0734=A/T 4th gear incorrect ratio. This has nothing to do with the speed sensor. If the speed sensor was faulty, it would also set OTHER gear incorrect ratio codes. My experience tells me the 4th gear incorrect ration indicates the torque converter clutch (TCC) is slipping and nothing more. Unless there was a speed sensor DTC (Diagnostic Trouble Code), the sensor is not the issue (yet). The fact P0734 was set (trust the computer), the TCC is slipping (out of range). Question: Maintenance history may indicate the wrong transmission fluid may have been introduced. Hyundai's Transmission fluid is strictly SPIII... there is no substitute. The incorrect fluid will cause 4th gear slippage. Now, having said that, it doesn't mean the 4th gear (lock-up) clutch isn't worn out. Have a qualified/certified Hyundai Service Technician properly diagnose this issue.

that depends on what is the cause of the problem in the box,,if you took the box sump down all you can realy do it change the oil filter or clean it, thats about all you could do yourself,,,there is nothing more than that,,, the 3rd and 4th gears are driven by cluches if there slipping its a rebuild sorry,,,bad news realy

DTC P0734 is "4th gear incorrect ratio" - that's your torque converter 'LOCK UP Clutch" It's worn out (or you're using the wrong Trans Fluid required by Hyundai - SPIII OR Both). The P1624 is simply the Trans Control Unit (computer) communicating to the Engine Control Module (ECM computer) MIL - on request signal to ECM = asking it to turn on "Check Engine" light. MIL = Malfunction Indicator Lamp. When the torque converter 'lock up" clutch slips or doesn't engage, the trans automatically returns to 3rd gear and stays there (it's called 'fail safe' mode) until you cycle the ignition key, then everything resets until the malfunction occurs again.
You'll need to have an AT (Automatic Transaxel) tester hooked up to verify this. Hyundai has a Service Bulletin specifically for "gear incorrect ratio' codes. If when you changed the trans fluid, was it done at a Hyundai Service Center? If not, someone may have installed the wrong fluid.

Yes, it could very well be a bad transmission.

First thing to do is check the fluid level if that ok you may want to think about having the transmission filter and fluid changed, there are other possibilities but check these first