I have a 07 auto that I bought in October and love it! I have noticed that my 1-2 and 2-3 upshifts are somewhat harsh. Not smooth and seemless like any other auto I've driven. The harshness can be lessened with either a super light or heavy acceleration. Just drives me nuts. Any input would be appreciated.

 

im far from an auto expert. my h3 is so smooth i can hardly feel the shift,for comparison.
years ago i read that smooth shifts were done by slowing down the gear change time,letting the bands/clutches slip,causing more wear but silky smooth and more wear!
shift kits speeded up the shift to be more positive and reduce wear.
old trans had a vacume modulator to help set shift timing,not used anymore i guess. they failed,causing odd shifts.
bottom line,i guess if yours is actually going bad,its something like a shift kit effect.

bottom bottom line ,,,change the fluid completly at a shop equiped to drain it completly,,then???

 

stinger95, are you sure you are not simply feeling the effects of a slightly underpowered engine wrestling with a 5000 lb vehicle?

I have no clue what drtom is talking about. My truck is not "silky smooth" when it shifts and never has been. If you are feeling any unusual delays in shifts or any really sharp engagements there might be a problem. Also, if you notice a change in the way it shifts, it is time to get it looked at. If it is simply not as smooth as other (translate lighter) vehicles, it may just take some getting used to. The fact that shifting under throttle and with neutral throttle is not a problem tells me that it is working like it should.

 

the years ago,were old caddies and lincolns that WERE silky smooth.
i knew it would get tricky,your smooth or mine,but my 2 h3 both the same ,barely feel a shift so if ure feelin it get help.

 

try clean vent tub on top of the transmisson and ck for broken vac lines

 

try clean vent tube on top of the transmisson and ck for broken vac lines

 

That's exactly what it feels like. An old muscle car with a shift kit.

 

The 4L60E is electronic shift controled by the trans control module. If you have towed something or another driver with a lead foot has been driving the vehicle it can change the trans shift adaptives which is how hard and when the TCM shifts the transmission through the gears. Any check engine lamp or Service Stab message lately ?

 

No check engine, but did get a service 4 wheel drive message not to long ago. Thought it was the 4hi "lock" button that was stuck in for a couple minutes bucause the message went away and it went back to 4hi. Can I reset the TCM to default myself?

 

by any chance did you check the fluid? mine did the exact same thing you are describing and guess what half a quart low on that $7 a quart gm approved vehicles, and what do you know it's like a brand new transmission, also you might want to think about changing out the transfer case fluid, did mine and it feels like it is running smoother, I have about 60k on my h3, the fluid that came out looked like brown oil from a chicken wing fryer. Good Luck