Recently, my 99 Taurus has been developing some transmission problems. It has an automatic transmission, and when it shifts from first to second or from second to first the shift is very rough. Also, when accelerating on a hill the transmission seems very hesitant to shift. Almost like it's hovering in neutral. I have a couple ideas on what it may be; however I would like some ideas from others if you don't mind.

In my opinion it is the main solenoid, a damaged separator plate, or possibly the assembly gaskets are damaged. Because of the hesitance on the hill I am thinking it is the main solenoid.

Take a look at the following for possibilities, and remember that sometimes what we think are transmission problems can actually be engine problems.



if it's def slipping, here are some possible sources of your problem:
(taken verbatim from the Ford Techtran manual)

1) EPC Solenoid
~inoperative or damaged

2) EEC-IV processor
~inoperative

3) Oil pressure
~high or low oil pressure

4) Accumulator regulator valve and plunger
~stuck, nicked or damaged

5) Number 12 check ball
~missing ball

6) 1-2 capacity modulator valve
~valve stuck, nicked or damaged
~spring missing or damaged

7) 1-2 accumulator assembly
~piston stuck or damaged
~seal damaged or missing
~springs damaged or missing


ACTION

Symptoms 1 and 2 require an electrical system diagnosis

Symptom #3 requires perfoming a control pressure test-service as required

Symptom #4-determine source of contamination or damage-service as required

Symptom #5 replace check ball

Symptoms #6 and 7- determine source of contamination or damage-service as required

Post in the Taurus Club forum (http://www.taurusclub.com/forum/87-engine-drivetrain/99883-slipping-transmission-help.html#post1029400)