I have a 1997 SL2 Sedan DOHC automatic transmission that is just at 110,000 miles and has had perfect maintenance and upkeep throughout it's life.

Just yesterday it started shifting through the gears very hard, as if someone was slamming the whole car each time the gears shifted either up or down.

The transmission fluid and filter were just serviced a few days ago and I wanted to know what the general consensus was.

My fiance's father is a former UAW employee and said it probably is a lack of pressure in one of the vacuum lines, but my question is which one and how do I determine which it is / replace it? He can't physically help me because I live on the coast and he's in the midwest.

Also through looking at other posts about this similar topic other people have said it could be: Throttle Position Sensor, Valve Body, Pressure Regulator, Transmission Shift Module, or even the Vehicle Speed Sensor.

Which makes the most sense and do you suggest I do this myself or pay a pro? (I've done a lot to this car myself and am fairly mechanically inclined)



Also a secondary problem I'm having is when I turn on the AC I have a huge loss in Horsepower and I wanted to know if there was something I could do, other than replacing the entire unit about this issue?

 

The transmission on these things is Electronic controlled. No vacuum lines that I am aware of anyway.
Slamming through gears, sticky somethings in side the transmission. Why Sticky.
Clue: you U just had it serviced.
Question:
Buy who or whom, was the filter changed? How was it serviced, there are different ways to do it.
was the correct fluid used,
Depending on who serviced the transmission, was it really serviced?
Yuh, I'm annal that way.
The wrong fluid can make things sticky.
Transmission fix it in a can has the capability of making things sticky.
Mine got a tad sticky after sitting in the drive way for 3 years.
After 6 months of quasi regular driving, it is back to not as smooth as silk, but it never was and it would scare me if it got that way.

 

Also go by Auto-Zone or the equivelent and have the codes read out. There might be a clue there as to what is going on.

 

1 Transmission shift module if you sit at idle and with your foot on the brake put it into drive or reverse and it slams into drive or reverse.

2 loss of power with the ac on in a 4 banger is normal. unless it is a discusting amonut, like it is stupid slow. then you may have another issue