Interesting immediate change stop slam from TRANS 2005 SS Impala
I had a couple of intermittent occurrences of the TRANS slamming into 1st pulling away from a light. I also noticed a shudder in the car after that occurred for while. Fearing the pressure control solenoid everyone states as the problem, I did some research. The car has 75,000 on it and I know the previous owner had it "flushed" at a 10 minute oil change. The fluid is red with a light tan tint. So, in my research I came across a bunch of people who had suggested to them that a varnish cleaner be used and then a full pan clean and full push out refill be done through te cooler lines making sure to use to full 14.3 quart capacity in the process.
So the most recommended varnish removing cleaner was Seafoam Trans Medic.
I sucked out a pint of fluid and put it in. Immediately it shifted smoothly both up and down and no start slams. Been 3 days without repeat. Next up the full change flush using a good grade fluid like Mobil 1 full synthetic.
if this doesn't stop it I'll put a 1/2 pint of TRANS medic back in. You can operated with it. I'll update if it works. Makes sense though. Solenoids a
Usually work or try don't. Ony something causing more force to be required from the coil like gummy varnish should cause an intermittent problem.
Side note, I've had one of these "flushes" done by an oil change shop. They only flush till the fluid "looks" clean. On my 01 that was 8 quarts. Told them that wasn't enough and they argued it was good. Because fresh fluid soluablizes old dirt, in a week the fluid was back to the same dirty color. Had them do it again but it still was back a week later. Lesson learned, don't waste your money. The pan MUST be cleaned and ALL the capacity flushed through. I also question highly the quality of the fluid they use.