Thread: Part (thin, flat metal) that falls out when changing trans filter

I know I've read about this before, so I'll apologize for the repeat post, but I'm wondering what happens if the little flat metal piece that should have stayed in the transmission isn't replaced in the proper position. I really don't want to drop the pan again to double check, as I wasn't sure how it was supposed to go, and I can't remember how I ended up replacing it. I now understand that the "V" should go up. My transmisssion works well enough (134,000 miles, don't know if it has ever been replaced), but it is slow to shift into fourth (overdrive), waiting until 44-45 mph. Strangely, if I engage the cruise control, it shifts into overdrive at slower speeds.

What, exactly does the thin metal piece with the V actually do? I know it redirects fluid at certain temperatures, but why? Also, could my trans be damaged by operation with the piece incorrectly installed? Any true transmission gurus out there?

44-45 is where mine always wants to pickup overdrive. See nothing wrong there. About the only thing I've noticed is that when the car is cold (first drive in the am) it won't lock the converter until it warms up to a certain point.