I've got a 2003 SS with 75,000 miles on it. I put a brand new transmission in it (everything but the outer shell) but it's still acting weird. The transmission shop can only guess that it's an electronic problem. I need to give the story though.

A few weeks ago, out of nowhere the transmission started jerking when it needed to shift up a speed (not while downshifting). It also shifted a a couple MPH earlier than usual. For example, if I was accelerating, it would still shift into 3rd at 23 MPH or so instead of staying in 2nd gear to accelerate faster. The service engine light was on, so I checked the code at Autozone. They said that the torque converter clutch was stuck on (very common problem for GM). I checked around and the cheapest I found was $800 to fix this $30 part or $1500 to replace the whole transmission (plus 12 month/12,000 mile warranty). I decided to just replace the whole transmission.

The shop put in a rebuilt transmission, everything but the valve body and the outer shell. When I picked it up the problem was exactly the same (odd because they test drove it). Since I had the warranty, they put in a new transmission (not rebuilt, new this time). After this, the problem was much better. The service engine light wasn't on anymore, but it still shifted hard/slipped about 20% of the time. I took it back and they put in a new valve body (I'm really getting my money's worth from this warranty ). Again this works better, but it's not perfect. If I accelerate normal or hard from a dead stop, it jerks once at the beginning. Sometimes it jerks slightly just after it shifts into first speed; the RPM's don't change when this happens so maybe it's downshifting into neutral for a second? These jerks only happen maybe 25% of the time and never in 2nd, 3rd, or 4th speeds.

The transmission shop can't figure it out. The only thing they can think of is some electronic/computer problem in the engine. This problem honestly isn't a big deal right now; I'm just afraid of it getting worse.

 

Keep getting it fixed under warranty until its fixed, it will probably get worse.

 

x2 with enzo because it has a warrenty and there is a good chance there is some thing wrong with some thing in the internals of the trans. like a bad clutch or a tooth on a gear is messed up make them pull it out and dissasemble it and go threw it if they keep saying some thing electronic most likly it is not. because it will be always in limp mode have them check the shift silinoids as well as every thing