A very likely possibility other than problems within the transmission itself would be the transmission mount. This is a rubber bushing in a metal bracket that supports the transmission by connecting it to the frame. When the bushing becomes worn it allows the transmission to move and it is very noticeable because the hard shifting of an automatic transmission is masked or absorbed by this bushing.
Hope that helps, good luck!
I would first check the u-joints in the driveshaft. But it sounds like the transmission rear mount is broken. CHECK TRANSMISSION MOUNT.
it is probably the input speed sensor in the transmission. i have the same problem and that's the cause of it. shifts hard going from first to second then a bit better going from second to third. and from park to drive. but if you put the car in reverse then jam it into drive quickly then it wont clunk lol. if you check the computer at a auto shop it will probably say turbine speed sensor no signal or something like that.
First thing to check is your fluid
Sounds like the front pump in the transmission is tired.
My 1984 corvette transmission is not shifting into overdrive. It shifts first thru third fine.
The "ECT" stands for Electronically Controlled Transmission. The "Snow" mode starts the transmission in 2nd gear rather than first so that the wheels don't have quite as much torque and are less likely to spin in inclement weather. Secondly, it changes the whole shift pattern of the transmission, particularly when accelerating from a start or when passing. It has the transmission change into higher gears earlier so that, again, when it is bad conditions you are less likely to spin the tires each time the transmission shifts up and when you go into a passing gear, it down-shifts only one rather than the usual 2 gears so that you don't have as dramatic a change in the power going to the wheels.
No shifts...jerky shifts....engine faster while car does not. All this while tranny has a full fluid level. Low level can cause the first three.
That is one possibility for that complaint
my 98 vw jetta atuo shifts hard in first but fine in 2,3
The LS has a five speed transmission. Therefore it shifts from first to second, second to third, third to fourth and fourth to fifth. Four shifts.
if its the GTA with the 5.7, the 700R4 is, in my opinion, the best transmission out there.mine is amazing, shifts on a dime, has a low first gear, and really runs great with the 5.7
I think it;s called the shift solenoid in the transmission!