My fluid is up to specs and very clean. No leaks. First I lost my reverse, then when I parked on my driveway, (which has an incline), it wouldn't lock into park. Held the brake down shut off the vehicle and then it locked into park. Turned on the vehicle and the lock comes off??

What's going on? (Please... can only shade tree mechanics shine in)? Anyone who just cleans and waxes his/her van on weekends and drops off the vehicle at the local shop for oil changes or any repair, please refrain from typing suggestions. I want to hear from DIY'ers.

I've already ordered a DVD on how to rebuild the transmission because I'm at that level. I'm hoping for the simplest repair resorting to dis-assembly last, (perhaps maybe a valve body rebuild)?

Anyone ever had this DVD:

 

Does the transmission move in a forward gear? If it doesn't, then I would look at one of the drive axles. The axle maybe broken at one of the joints.

 

Lock issue was fixed with a new shift solenoid. But still no reverse. Transmission goes into all shifts except reverse. I use it daily without any problems other than parking slots were I have to use reverse.