superk
I'm surprised nobody has suggested engine miss due to weak ignition coils. I had the exact problem you are now experiencing. Under load at about 3200 rpm shaking and vibration. Let off the throttle and it smooths right out. Had 2 weak ignition coils. Replacing them totally fixed problem. Which one is the problem? You have 10. The dealer will diagnose for about $100 plus $200 each to replace and you will be good until the next one fails. This is a common problem. I suggest you go on Ebay or Amazon and buy a set of 10 for about $150 total and find someone to change them if you can't do it yourself. Even Rock Auto sells them for $17 ea.
Please do yourself a favor and check this out before you start mucking with driveline or transmission.
