Just to mention one possible thing to check - I'm not familiar with the T100, but on some other Toyotas, if there's too much grease that's been pressurized into one or both of the driveshafts' grease zerks at the slip yoke, then it'll physically skew the transmission forward or back enough to cause the exact same symptom that you're describing. It's easy to check for that problem - just use a small screwdriver to press on the tip of the drive shaft grease zerks. Have a shop towel available. See if tons of grease wants to come out and the transmission position changes.