This may be a little lengthy but i want to make sure i give all the info. I have 2007 chevy silverado 2500 hd ,6.0 engine and 4l80e trans. When i drive the truck and get it up to temp then stop and put it in reverse, it feels like the torqueconverter is trying to lock in and the truck tries to ckohe down. If i let off the brake it goes backwards like you let out on a straight drive in reverse. It also felt like the converter would lock soon as i pulled off in drive. I have a buddy the works at the chevy dealer and he changed the converter ,fluid and filter. Now it is fine in drive and better in reverse . Sometimes it will still try and lock up in reverse and sometimes it will act just fine. If it tries to lock in reverse at idle i can cut the truck off then start it back up and it will be fine. What i mean by fine is it sits and idles like it should and eases off in reverse like it should. I bought the truck used and it was like this when i got it.

Thanks for any help.