Why is my gearbox playing up after having to replace the alternator today????

[MelB Lurker Find all posts View Profile Close MelB]

I had to replace the alternator in my 2008 Diesel auto Prado today and when i picked it up and was driving home the gearbox was taking ages to get in to top gear and then once i got home, i phoned the mechanic and he asked me to bring it back to him and then when i put t in to drive it made a clunking noise, he told me that it may need to be re learnt???? the gear box was perfect before i replaced the alternator, does anyone know if this is the case???? sorry for the vague information but being a female i am not mechanical minded.