Chrysler Repair: chrysler mini van 3.8l v6 awd: bucking/shifting problem, 4 digit numbers, odometer reading

Question
I was driving to work and all of a sudden I heard a clunking noise from the engine area, and my van began to buck and seemed to shift into a lower gear, pulled into work and then I tried to get it to move again slowly and doing so but bucks crazy, then when engine is on i have no reverse and no neutral, when i turn the engine off, and shift into neutral i can move it. Can this be the transmission? all fluid are good, and nothing looks out of place underneath.. thank your anticipated help!!

Answer
Hi CJ,
The several observations that you made are consistent with a transmission problem. The automatic shifting into a lower gear by itself is a self-protective effort that is designed into the controller which is called "limp-in" and where the shift is into second gear which is the position of minimal parts involvement. Then the loss of reverse would point toward that clutch which is used for low and reverse not being accessible. The controller probably has recognized the malfunction and placed a fault code in its memory. You might try the ignition key:"on-off-on-off-on and leave on" doing that in 5 seconds or less elapsed time. The watch either the check engine light which remains on to begin to flash, pause, flash, etc. Count the number of flashes before each pause, then group them in pairs to form the 2-digit fault codes (this applies to '96 and earlier models) OR observe the odometer reading to see if it shows some 4-digit numbers (more recent year models). It may be in the latter 90's models that the codes will only be known by plugging in a diagnostic readout box to a plug that is under the dash to the right of the steering column. The codes will help direct the diagnosis toward an appropriate repair.
If you get any codes, let me know. Otherwise you might want to have the vehicle towed to an independent transmission shop (not a nationwide franchise) for a diagnosis.
Roland