On the way home I tried just that and after a few tries it finally came in but with a delay of about 10 seconds from switching. A few more goes got the delay down to a second or so. As I was nearly home I left it at that.
Tonight Pam & I went out for a drive and after a bit more use the overdrive comes in almost instantly. No Bachman, no Turner but I've got overdrive.
What a difference it makes. The car is much more relaxing to drive.