Hello,
I bought my 05' tl in the spring with 143k miles. Shifted fine when I bought it. As the summer heat came it seemed to shift different. Not bad just different. It almost has a bit of a "lunge" from time to time. Wasn't sure what it was from. I did a 3x3 fluid change, and changed the internal filter. Seemed to help, but still did it. Now that fall is coming in its shifting better now. Maybe I'm crazy but I think the weather is affecting it. It seems the worst in humid weather. Anyone else experience this? Does this mean something? Any input would be greatly appreciated.
Thank you

 

Not sure, maybe the heat thins out the oil (just a guess). I notice the shifts too, especially in low gears. 1-2 is really noticeable and 2-3 a bit, but much less. I noticed it in my tl tranny that I just replaced with an accord one. I still notice the shifts with the accord tranny and I recently took my buddy's TL for a ride to see how it shifts and same thing. I dunno, I think/hope this is normal with these cars

 

yes the cars shift differently when it gets warmer outside. unless it is doing something obviously wrong, don't worry. you can change the fluid if it is old...

 

Mine always has since it was a couple years old. Changing the pressure switches helps a lot.

I think a lot of it is the engine is making considerably less power than it would in the cooler months. The throttle is opened further, if the switches are out of calibration the throttle timing is off and you end up with a bump shift, the throttle opening back up before the shift is completed. It probably has something to do with the shift timing vs line pressure rise as well since line pressure rise is determined by actual torque output and timing is electronic which isn't going to change by temp other than by the switches being off..

All you can do is have a decent fresh fluid in there and make sure the switches are no older than 2 yrs.

 

I notice it with my 07 TL-S, I've done 3x3 fluid changes and a drain & fill every other oil change. Changed my pressure switches aswell before doing the fluid change. None of which has really helped my car. Thinking about changing up the fluid next with some Redline mix.

I wonder if it's possible to use a newer TL Transmission 09-11 FWD 5at, whenever I drove one of these cars it shifted a lot smoother than our TL's. I know it wouldn't work with the 3.2 but it will with the 3.5 due to the bell housing.