[Ford_Girl]

My husband and I recently purchased a 1997 Ford Taurus G. When we purchased it it needed a head gasket, and my husband replaced it. It has roughly 192k on it. (Poor car wasn't really taken care of, I think it had original head gaskets on it!)
On a road trip from Arizona to Louisiana, the cars transmission randomly down shifted out of OD to Third. Husband slammed the gas pedal went to 65 and it shifted fine.
Then during in town driving it would not shift out of first until about 3500 rpm's or higher on slow acceleration. It only happens once the tranny is warmed up and shifting into drive is a hard engagement like the torque converter is locked up. Letting the car cool eliminates issue until warm again. It also randomly down shifts when warm.
I would like to fix this but don't know where to start. Any advice is appreciated. (Not sure what tranny we have either.)

 

[glyphmon]

Ford_Girl,

Taurus G was about the lowest trim model in that year, IIRC, so it's most likely the Vulcan engine (3.0 OHV) tied to the AX4S transmission. Since it seems to be a problem as the transmission warms up, an additional aftermarket transmission fluid cooler may be of sizable benefit. It is a recommended modification to all Taurii/Sables of the first four generations anyway, but since yours is demonstrating these kinds of signs, it may be of more immediate benefit to you. Others may chime in with additional suggestions.

 

[Monsoon]

You need to determine the health of the transmission. If the tranny fluid was not change on regular intervals, anything is game to go wrong. As stated above this is the lowest trim line for this model and among all the trim lines this has the weakest transmission for its year.

Next is the engine, the engine needs to be operating fairly well. A vacuum reading between 18 to 22 inches is normal at idle. You may need to adjust for altitude.

If the engine vacuum has a large variation in vacuum or is uncontrollable I can only imagine the computer may be mis-shifting the transmission. I believe these transmissions are electronically controlled based on sensor data. The computer will only shift based on the data given, whether the data is good or bad (out of normal range).

In a nutshell the engine and transmission should be in a healthy state.

 

[Ford_Girl]

Thank you for the replies. When we bought the car, there were receipts for work that was done to it in the glove box. It had the TSS replaced less than a year ago so I called them. I explained what was going on, and he said that he had the tranny out of the car to inspect which means he had to redo seals and things of that nature. The fluid had a flush on a different receipt, new filters ect.
My husband and I went and got a TRS/ neutral safety switch and replaced that today. We went for a looooong ride to heat to see if it would fail as it normally would. It hasn't had the issue as of yet. My husband is calling it fixed. If there are any recurrences of the issue, I will let yall know!!

 

[sheila]

If problems reoccur, i would change out the vss (vehicle speed sensor) based on the extended 1-2 shift, although dbfruth was able to solve a harsh 1-2 shift on a vulcan by changing out the tps (throttle position sensor).

 

[sheila]

It sounds as if the tss (turbine shaft speed sensor) has already been changed.