Ok, I have around 20k on my car, the car started to shift VERY hard the first 2 or 3 gears when in auto. This only happens when the car is cold. Sometimes when I leave to go to work in the morning, the tranny will not shift to 2nd gear!! even if I go to sport shift and shift to 2nd, the indicator will indicate 2nd for a couple of seconds, but the car does not shift, and the indicator will go back to 1st. The car will just rev very high in 1st and after a 5 or 10 seconds, it will finally shift very hard into 2nd. Once when I was in sport shift mode and I manually shift into 2nd, there was even a clunking sound when it shifted, but that has only happened once. This happens only when the car is cold.. anyone have any ideas???

sounds like a bad modulator. Does anyone know if the TL has a vacuum modulator? If so, it could be a leaking vacuum hose as well.

well since it is under warranty. it needs to go to the dealer.sounds like a a-b switch or just a bad trans. there just like the 2nd gen trans but better gears, better cooling and shift points. but are kinda the same.we all know the problems with the 2nd gen.

dealership trip....keep us posted...

If it only happens when cold I would start by checking the fluid level.

Trew- no modulator and no TV cable. It's all electronic. I actually miss the simplicity of the older stuff.

Acura's 5AT SUX!!! they cant get it right. My 07 TL-S shutters when going real easy on the gas from 2nd to 3rd and 3rd to 4th, makes my car shake. When i bought it I thought the the tranny problems were only happening with the 2nd gens.
I cant believe i bought another Acura...

^ dunno what you're talking about. Going on 3 years and i've never had a problem - with ANYTHING.

Have u tried flushing ur tranny fluid. Try that GM tranny fluid, dunno if its right for 5AT,but I heard it works so who knows. My 3rd gear is having problems too, I should try out that stuff..hope it saves me a trip to the dealership! Good Luck!

GM Syncromesh = BAD!!!! for the 5AT TL. That is MANUAL transmission fluid, not AUTOMATIC. USE THE HONDA FLUID FOR 5AT

if your trans is acting up cold, it's toast

I have Amsoil tranny oil inside completely. Think that might be causing problems? shouldn't though...

amsoil is ok and wont cause the problem- that anyone knows~
but most of the people using it are all higher mileage TL of gen2

Sounds like you have a bad clutch pack- when they replace the trans leave it on its honda fluid to be safe