Isaac125

Hi,

The GM dealership in my country does not scan and fixes corvette transmission problems, due to the fact that they don't know a thing about this car (not imported regularly).

The problems I have are on the Z51 09, the gear kicks, slips, and just not smooth shifting.

Do you recommend to try change the transmission fluid before going to someone who will have the courage to open the gear?

FireRoc

Is it doing this in all gears or just some? Did this just start recently, or ever since you have had the car (for how long)?

Do you know what type of fluid is in the transmission now?

Are you sure that the clutch is fully dis-engaging when you shift? Is the clutch resevoir full or low on fluid?

Isaac125

1. It started 4-5 months ago, 2 months after buying the car. knowing the previous owner I know for a fact that it never happened before.

2. The fluid never been replaced, it's the original that came with the car. It's automatic transmission, no clutch.

There are some problems, not just one:

1.After starting the car at morning (cold engine), and driving in reverse for 3-4 meters, when I move the gear to D it has 1 second delay and then you feel a strong "kick", after that you can keep on driving normally.

2. 2nd gear has the same "kicking" problem, when changing down from 3rd to 2nd it gives you a small kick.

3. from 3rd to 4th it sometimes slips, like taking a small "breath" between shifting.

and constantly, the power gain in 3rd 4th and 5th is not in a straight line, it's quiet odd and I posted some videos here 3-4 months ago when it started.
The meaning of the is that the rpm kind of "drops" after several seconds in new gear, and then builded up from scratch.
You change from 3rd to 4th, pushing the gas all the way down, get to 1800-2000 RPM and then out of no where it drops down to 1400-1500, like you changed gear up, but you didn't.

Any thoughts?
All the fun from the car is ruined

FireRoc

Ah....automatic.......not something I know a lot about, but here goes. Hopefully others will jump in.

To me, it sounds like the bands are slipping due to low hydraulic pressure in the transmission. So it could be due to clogged oil passage, clogged filter, bad pump, etc.

Agree, the first step would be to change the fluid......especially if it is brown or smells burned (on the dipstick). If that does not do it, it problably needs to have the pan dropped and cleaned. Past that I would think it needs to be re-built.

Hope someone else can add more ideas.

el es tu

at a stop there is a noticeable kick when switching to D or S

if you floor it in auto mode it will have a lag in its downshift - this is due to the skip shift and torque management

you may want to have the car retuned - the stock shift times suck

RicK T

Everything you describe sounds fairly "typical"........however it shouldn't be normal but many dealers here tell us "it's normal".........that's what I was told when I took my '08 in, and of course GM Customer Service was of no help. So it comes down to whether or not an owner can shop for and find a dealer service dept willing to fix it even though they can't duplicate the problem or consider it "normal".

GM issued a PI (preliminary information, which is not quite a TSB) for it supposedly only applying to '08 model year cars but many cars from many other years have the problems........at least as reported around here.

The main culprit is the factory programming for the TCM, especially the Torque Management.

Here are some prior discussions for you to read, including the PI, known as PIP-4395:

http://forums.corvetteforum.com/c6-c...-shifting.html

http://forums.corvetteforum.com/c6-t...ip-4395-a.html

http://forums.corvetteforum.com/c6-c...ip-4395-a.html

http://forums.corvetteforum.com/c6-t...lp-please.html

My opinion, your best bet is get an aftermarket trans tune.

Cliff Harris

A little late, but this guy fixed the exact same problem (delay when shifting from R to D and then engages D very hard) with a TSB modification (see post #13):

http://forums.corvetteforum.com/c6-c...-problems.html

cclive

Fluid level may be low...if you are going to go under and check it (no dipstick) then I would suggest new fluid and filter while you are there.

hydbyj

mine slipped between 3rd and 4th gear, after talking with folks i changed the tranny fluid with a complete flush, including the torque converter. that helped, but i sometimes have that same slippage, just not as bad.

jerry