had this happen on mine when I installed the first T-A valve body. Luckily, my car was still on jack stands when I found it. Talked with Paul Forte about it over the phone, and he was convinced I had done something wrong (as was I), but agreed to take a look at the valve body, so I sent it to him. He called me a week later, said he had installed it into his test vehicle and it did the same thing. Locked up in D. He appologized profusely and sent me a new valve body which worked fine. My point is simply that it could be in the valve body (???).