Vibration after tranny rebuild

Just got my 2000 sle back. Transmission was rebuilt, new torque converter and pump. All electronics were replaced as well (what they told me). As soon as i started to leave the parking lot i noticed a vibration accelerating. Car can be in park and if i hold to around 2000 rpm it feels like those rumble strips on the road. I told them and they said valve body wasn't replaced but put larger pistons in. He said give it about 2000 miles to break in. I saw some posts saying it could be the torque converter or a pressure problem. Or will it just break in like he said?

That's total bull......there is no "break in" period for a vibration in a transmission....what was the original concern and their "fix" for the concern? Was the CE light on? Were codes set? Was the vibration there before the work was done?

Doesn't anybody road test their work before giving it back to a customer anymore?

Local garage, chain, or dealership?

Park the car in their lot, ask for a loaner, and tell them to call you when it's fixed right......I'm sure you paid big bucks for this job....

Well the transmission has been going for quite some time. Had the pressure valve out that caused the hard shifting and the noticeable "whine". It would also slip from time to time. So I knew it was only a matter of time. I guess what happened was the transmission cooler was 80% blocked and the torque converter seized to the pump shaft. So I had a new torque converter and pump installed as well. I noticed it as soon as I got in to drive off and mentioned it. He just told me because they put "larger" valves in the valve housing and to put 2000 miles or so and if it was still doing it to let him know. It was not doing that before at all. The only code that he said was set was transmission slipping. So the transmission was completely rebuilt with a new torque converter and pump. It was what I thought was a reputable establishment in business for over 35 years. Paid about $2000. I guessed that they didn't do something right and instead of having to take it apart again figured I would drive it until the warranty was out. Which is 6mo/6000 miles. I was kinda hoping that what he said was true. Just because of the inconvenience.

I wonder if they cracked the flex plate when they put it back in. That would explain a vibration even in park.

I have done a few 4T60E( somewhat different trans I know ) rebuilds on my own.. I have never had one that felt like it was out of balance or that had a jiggle or shake.. They were all smooth and all lasted way more than 6 months.. I never gave it any time to break in either..I built one for my van at one point.. I bought $600-700 in parts.. I wish I could say it held together, in the end the reman torque converter failed...I did put a lot of hard miles on it.

My guess is one of 2 things like stated above, possible cracked flex plate.. As well if they remove it( don't see why they would need to ) its possible to bolt it back on 180* off, leaving the counter weight on the wrong side causing the engine to shake like a leaf..

The other could be a piss poor rebuild..

By chance is the car down on power? Does it feel like it could have a dead cylinder? Check engine light ?