I got a 2006 dodge ram 1500 with 161,000 miles on it. I have noticed lately that if I back up or go forward slow there is a grinding sound I dont think its the transmission but from the rear axle. It does go away when I accelerated through. I have also noticed if say I slid the ignition key and dont get my truck stared it takes a while after that of holding they key to get my truck going. Spark plugs maybe going bad? That is what I am thinking on that. Let me know what you think!!! Thank you!!!