I have an 03 Z06 With serious Problems. It all started roughly three months ago I was driving the car (obviously), the shifter jammed up and would not go into ANY gear clutch in out, car on or off. I took it to NUCAR chevy in Delaware. 120.00 later they told me nothing was wrong about a month ago it did it again. I took it back they tore the trans apart that second gear and syncros came apart and trashed the trans. They replaced the entire trans under the GMPP warranty. Two weeks ago again driving I went to shift into second let out on the clutch and it popped out tried to put it back in and it grinded. Took it back to the dealership they broke down the trans again and replaced second gear and syncros again. I told them to check the linkage they said it was fine. My question is. Is this a commom problem with these vettes. The car doesnt get beat on........much. If it happens again I would like to have a little more info on the car. to tell the dealership

 

I had problems kind of like what you've described on my 2004.


Even if you don't find this story useful, I'm sure someone else will as I didn't find much info when I was looking on the forum for my trans problems.


It's not a short story and it's still going on...

Before I got the fluid changed, I had problems getting into 5th gear at speed. I then started grinding in reverse. Later in the day the car got stuck in reverse and wouldn't come out. I ended up yanking hard on it and got it out of reverse but then for a while it wouldn't go into reverse, it would just grind.

A forum member told me to try putting it in reverse with the car off. That worked enough for me to get it to a shop to change fluid (fluids were mostly original with 4 years on them).

After the fluid change and trans linkage adjustment, the car drove alright for a couple of days. Reverse still did the grinding thing but I could at least get it to work.

Like the second time I took the car out, I was late for a forum cruise and was driving to make up time. I got there and we left.

About 2-3 minutes after leaving after getting on the highway, I went to shift into third, and the shifter was moving freely. I could move the stick all around like there was nothing attached. I think it was stuck in gear since I got it to a shop driving at 55 MPH at 3500-4000 RPMs.

When the transmission was being taken out at the shop, it was discovered that a pin had fallen out of the transmission linkage and there was no connection to the transmission. The car was put back together and it mostly works again.

Reverse still grinds if you don't go to sixth first. The shifter was adjusted but getting reverse to work perfectly caused second to pop out. Right now I have only have to deal with that reverse thing.

I've heard that it's the fork that is bent or something. It will be expensive to get the trans taken out and investigated. I will eventually get it all fixed.

I was told that it was my hard shifting (and yanking the car out of reverse) that caused the problems with the transmission. Also I was told that I should stop shifting hard to prevent further damage. He said that I could get an aftermarket shifter with adjustable stops to prevent hard shifting from further damaging the transmission. I am getting the Hurst Billet Plus installed soon since it has the adjustable stops, and it's cheaper than a new trans at this point.

That's pretty much my transmission story so far... I don't want to keep putting up with it, so any new stuff is going to be stronger and better built than what is going out.


I know a guy that has had transmission problems on his Z06 and he isn't driving it right now because he says his differential is going out.

I've heard that these transmissions have problems. I imagine that it is due to hard shifting since I've heard that you don't need to upgrade until you hit high power levels. However, why would there be upgraded stuff from RPM Transmissions and Dynotech Engineering if the stuff was strong enough from the start. I was at stock power levels when stuff broke.

Fresh fluids are a good thing and probably would have helped. My transmission fluid was black and cooked when it came out. I've only seen the high transmission temp warning once.

I was going to keep the car stock until I started having problems and stuff.

These days, I'm thinking that it's not a bad idea to build it up better than Chevy did.


I hope all that stuff helps someone out there with transmission problems.


Take care and have a good one,


Grant

 

Ok. I'm guessing you are doing some fast shifts occasionally. If you miss a shift in these things (start engaging the clutch b/f the shift is complete in a speed shift) it will wipe out the cheap stamped synchro keys. You need to put a steel 3-4 shift fork in, bronze fork pads, and billet steel synchro keys. These things are notorious for tranny problems, b/c GM cheaped out here. If you have an aftermarket shifter it will increase your likelihood of tranny dammage too, b/c the increased shift effort will likely make you miss a shift until you get used to it. The amount of HP isn't usually the problem, driver error is, and these things stock don't tolerate it.

 

The first trans definitely had some hard shifting on it but the BRAND NEW one most definitely did not when it went back to the shop maybe 25-50 miles tops they had to put second gear and syncros in......at least thats what they tell me... At first I thought they had put a used trans in it, but i verified that it was indeed brand new. Thats what concerns me the most. Driver error does do a lot of damage and I know Im not the best, but the new trans only had like 50 miles the old only had 17,000 miles