My chevy truck made a large bang after backing out of the driveway and put it into drive. Since that happened the transmission will jump out of park and roll a foot or so before going back into park. This happens at med to high idle and it will do it every minute or so. It will wake you up for sure and the panic on the passengers face is not good lol! It sounds like grinding as you take off down the road for about 50 to 100 feet then quiets down. Trans does not slip in gear or act differently other than this problem. I don't trust it now, I don't want it to take off down the driveway by it self. Trans is stock other than a hydraulic lock up valve being installed in it from superior trans. I had a trans shop put that in and it has worked fine for 5 years now so I don't suspect that. I have checked the linkage it is adjusted fine. The truck is 4WD and transfer case is stock also. I have never come across this before. When it jumps out of park it is quit a jolt it does not do it at normal idle as frequently maybe about 2 or 3 minutes it will do it. Has anybody seen this before.
- posted
17 years ago