I was plowing a parking lot doing minor clean up. After I had been plowing for 20 minutes, when I shifted from reverse to drive there was a clunk that shook the truck. It did this in 2 or 4 wheel drive. At first I though it was universals. I got home and turned the truck off and went in the house for 10 minutes. I then got my older son to shift from reverse to drive and back several times. I could not get the truck to do it again. I then went and plowed another area for 15 minutes and the truck has not done it since. Any Ideas.

Thanks

2004 Chev D/A

It's not uncommon to get a weird shift every once in a while. You probably just confused it for a second. If it doesn't happen again I wouldn't worry about it.

Thanks, I just hope it doesn't do it when I need it most.