Check the drive axle for a broken and leaking boot or bad CV joint.
You forgot to let your wife in
It's really hard to understand what you're asking here."What causes a knocking sound when your car drops into a hole while driving?"If that's your question, I imagine that it would be the sound of your car dropping into a hole.
Gearbox oil needs changing.
It's the spirit of the car knocking on the side saying "HELLO??? TAKE ME TO A MECHANIC!"
If it only happens when backing up, you may have the parking brake engaged.
The combination of fuel still being pumped into the engine and air
Probably you have a bad tie rod (maybe both). You can find it on eBay (around $50.00 L&R). Knocking when turning on front wheel drive is most likely the knuckle on the axle. Look at the rubber boot on the end and I will bet it is split.
are you sure the noise is coming from the transmission. most cars will make a knocking sound due to the lifters being a little stuck. to see if it is a lifter noise, at the net oil change use a qt of lucas oils. there will be one that says something about lifter noises on the front, found at any parts store
the thing that causes a clunk when you turn means that the break pad isn't turning all the way with the car tire and it is slightly knocking on the inner tire or something along those lines
You need to get your car checked.
The engines timing could be advanced to much. If it's a front wheel drive a CV joint could be going bad. Knowing a more precise area of where the sound is coming from might help to identify the problem.