Transmission slipping at low speeds - 2000 Mercury Villager

the process involves plenty of hydraulic fluid as well as gears and clutches.
If you have an automatic transmission, and it "slips" while you are driving it-that is, the car engine revs without the power going to the wheels-the most common cause (though not the only possible cause) is low transmission fluid. If the slipping is caused by low fluid, it will get worse as the transmission gets hotter.

You may be low on transmission fluid or the transmission is goig to fail.

If the tachometer is increasing (or you can hear the engine reving faster), then the transmission may be slipping - assuming constant speed. You should check the auto transmission fluid level at once. Low fluid can cause this. Slipping usually will happen when the transmission is hot - so it is less likely to happen when - for the first few miles. Most auto transmissions require checking be done when hot, and idling in park on a level surface. The fluid should be pinkish-red and have an oily smell. Brown colored and burnt smelling fluid is not a good sign. You may be able to flush and fill the transmission to save it - - but no one will tell you it will definitely work or not. Good luck!

it dont lie, it is slipping.
the TCM sees the input speed and output speeds, (trans)
and knows the slip rate. (TC's do slip naturally) and then if it slips too much. it throws the DTC,
must folks do the full flush service. and pray it fix it. (filter and all new ATF fluid)
is the ATF LEVEL too low or too high?, (the test is in the operators guide. not checked at all like the engine, RTM first)
some newer cars have no A./T dip stick to do this, and needs under car, check.

just take it in for service. and check the trans.

ATF = automatic transmission Fluid, RTM means read the manual.

If you mean the engine speeds up, but the vehicle doesn't speed up straight away, sounds like your clutch is slipping (manual transmission). If it's an auto, bands in the auto box slipping or low transmission fluid. Hope that helps?

A/T or M/T (auto or stick ,we dont know)
n moving in drive, reverse or Low or 1? or 2? (me too lazy to look what tranny you have)
it can be 2 things
1: lack of engine power
2: bad clutch or transmission

who do we tell? easy
you step on gas , RPM goes way high and MPH dont. (slips)
tranny slip.
you step on gas, RPM tracks with MPH, good ,
you then do the 5second max. tranny stall test in every car FSM made. and see the stall speed, with brakes hard set.
too high is tranny slip
way to low, engine power POOR.

alldata.com has all this on tranny. stall speed.
the FSM turn to on car A/T service, see STALL test.
bingo.
or youtube the vast number of videos on topic, stall.


wont move at all ,can be :
brake drag (passes stall test)
but first , the tests are, for bad engine or trans,
pick the one it is , state so, and we can go much farther.

IF you have a cable clutch (manual) look for a reason the cable is causing the clutch to slip when the motor shifts position. IF auto and cable select check for same problem. Check for bad or loose engine mounts--all mounts.

code p0720 refers to output shaft speed sensor(OSS)--circuit malfunction====causes--wiring--OSS sensor--ECM/TCM
of it has just happened check the wiring and connections to the transmission for water and corrosion or replace the OSS sensor in the transmission.

CHECK FOR LOW TRANSMISSION FLUID LEVEL.IF FLUID LEVEL OKAY, BUT TRANSMISSION FLUID LOOK DARK SMELL BURNED, CHANGE TRANSMISSION FLUID AND FILTER.HAVE GARAGE OR DEALERSHIP CHECK ABS BRAKE SYSTEM. YOU COULD HAVE FAULTY WHEEL SPEED SENSOR OR ABS BRAKE MODULATOR SOLENOID PROBLEMS.

Transmission speed sensor is most likely bad. Professional mechanic can determine with Ford OBD device.