[deerhunter5639]

Just recently my transmission (I'm assuming) has begun to make a buzzing/rattling sound. It only does it when I'm in drive or reverse and sitting stopped. I don't know if it's just my imagination but the truck doesn't seem to be accelerating as quickly as it used to. I mean it still drives fine, I'm just worried it could be something that might lead to a serious problem. And it doesn't do it all the time. I know nothing about transmission work so any advice would be greatly appreciated. Thanks

-Collin