Hello I'm new to this but I have a question I hope someone can help me with. I'm looking to buy a 2008 Chevrolet 2500 with 170,000kms on it. It has a 3 in lift and 33 inch tires. I have taken it for two test drives, first one went good, today I went to take it for the 2nd and take it to a shop to get them to look it over, but it left the lot and stopped at a red light, I went to go and it just revved like it was in neutral, it also made a clunk sound when shifting. I shifted into reverse and it was fine, I shifted into drive again and nothing, so I backed up into the lots again. The sales man got in and shifted from reverse to drive a few times and every time it made a slight clunk going into drive. Also the engine light came on when this happened. They pulled the pan on the tranny and it was empty, they said the fluids have all been changed shortly ago. And the test drives were only a couple days apart, and it worked fine the first time and there is no fluid on the ground where it was parked? Does this sound real or just a dealer line to hide a larger issue.